风力发电技术外文文献翻译
毕业设计风力发电外文文献
Abstract--The purpose of this paper is to find an innovative, high efficiency, practical and low cost control system structure with an optimized control strategy for small-scale grid-connected wind turbine with direct-driven permanent magnet synchronous generator (PMSG). This research adopts the sensorless vector control strategy based on phase-locked loop (PLL) for PMSG control, and the grid-side inverter control strategy is based on the single-phase PLL. The simulation demonstrates that the sensorless control strategy and single-phase grid-side inverter control strategy are practical solutions for grid-connected PMSG wind turbines, and they can provide both generator speed control for optimized wind power tracking and good power quality control for electricity delivered to the grid. The designed system offers many unique advantages, including simple topology, optimized control strategy, cost-effective and fast respond to grid failures.Index Terms--Maximum power point tracking (MPPT), PMSG, pulse-width modulation (PWM) converter, speed control, variable-speed wind turbine.I. I NTRODUCTIONn recent years, great attention has been paid on renewable energy sources, such as wind and solar energy. Wind energy is the most popular renewable energy source due to its relatively low cost. The overall system cost can be further reduced by optimal control of high efficiency power electronic converters to extract maximum power in accordance with atmospheric conditions [11].The wind energy conversion system based on permanent magnet synchronous generator (PMSG) is one of the most favorable and reliable methods of power generation. Reliability of variable-speed direct-driven PMSG wind turbines can be improved significantly comparing to doubly-fed induction generator (DFIG) wind turbines with gearboxes. Noise, power loss, additional cost, and potential mechanical failure are typical problems for a DFIG wind turbine because of the existence of a gearbox. The use of direct-driven PMSG could solve these problems. Moreover, low voltage ride through (LVRT) is also a big issue for DFIG because the This work was supported in part by the special funds from Beijing Municipal Education Commission.Chunxue Wen, Guojie Lu, Peng Wang and Zhengxi Li are with the Power Electronics and Motor Drivers Engineering Research Centre, North China University of Technology,Beijing,China(e-mail: wenchx1980@, lugod307@, catdapeng2008@, lzx@).Xiongwei Liu and Zaiming Fan are with the School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston, PR1 2HE, UK (e-mail: xliu9@, zmfan@) electromagnetic relationship between the stator and the rotor is more complex than PMSG. Therefore, it’s more difficult for DFIG to solve LVRT problem safely and reliably.In a variable-speed PMSG system, vector control approach is often used to achieve nearly decoupled active and reactive power control on the grid-side inverter which is a current regulated voltage source inverter. In this way, the power converter maintains the DC-link voltage and improves the power factor of the system [1], [7], [10]. Different control methods for maximum power point tracking (MPPT) in variable-speed wind turbine generators have been discussed in [2], [4], [7].This research adopts the sensorless vector control strategy based on phase-locked loop (PLL) for PMSG control [2]. The method requires only one active switching device, i.e. insulated-gate bipolar transistor (IGBT), which is used to control the generator torque and speed so as to extract maximum wind power. It is a simple topology and low cost solution for a small-scale wind turbine because of the sensorless vector control strategy. The grid-side inverter control strategy is based on the single-phase PLL, which applies a control method in Direct-Quadrature (DQ) rotating frame to single-phase inverter and achieves superior steady state and dynamic performance [6].For small-scale wind turbine, single-phase power supply to consumers is popular. There are many control methods for single-phase inverter, such as PI controller, quasi-PR controller, etc. [5]. However, these methods can’t decouple the active power and reactive power so as to have good power control performance. Single-phase PLL method based on DQ rotating frame can well solve this problem. On the other hand, encoders are vulnerable components for wind turbines, particularly for small wind turbines, because small wind turbines experience severer vibrations than their large counterparts. The sensorless vector control opts out the encoders, and therefore the reliability of wind turbines is much improved. For these reasons, the sensorless vector control and single-phase PLL method have their unique advantages for small-scale wind turbines.This paper is structured further in following three sections. In section II, the principle of the full power back-to-back PWM converter is introduced. Then the vector control of small-scale grid-connected wind power system including sensorless control, vector control of PMSG, single-phase PLL, vector control of grid-side inverter are described in section III. Finally, in section IV, the simulation results and conclusion are given.Vector control strategy for small-scale grid-connected PMSG wind turbine converter Chunxue Wen, Guojie Lu, Peng Wang, Zhengxi Li Member IEEE, Xiongwei Liu Member IEEE,Zaiming Fan Student Member IEEEIII. T HE PRINCIPLE OF FULL POWER BACK-TO-BACK PWMCONVERTERTypical topology model of direct-driven PMSG wind turbine is shown in Fig. 1. Converters of the system adopt back-to-back pairs of pulse-width modulation (PWM) architecture. The generator-side converter controls the generator speed in order to achieve maximum capture of wind power, and the grid-side inverter controls the stability of DC-bus voltage and the power factor of the system. This topology can be a good way to improve performance, and the control method is flexible. Converters have four-quadrant operation function, which can fulfill the generator speed control anddeliver the fine quality of electricity to the grid [7], [8].Fig. 1. Topology of permanent magnet direct-driven wind power systemIII. T HE VECTOR CONTROL OF SMALL-SCALE GRID-CONNECTEDDIRECT-DRIVEN WIND POWER SYSTEM CONVERTERFig. 2 shows the back-to-back PWM voltage convertervector control block diagram. The machine-side PWMconverter controls the electromagnetic torque and statorreactive power (reactive power is often be set to 0) byadjusting the current of the d-axis and q-axis of the machine-side converter. This control mechanism helps the PMSG tooperate in variable speed, so that the wind turbine can workwith maximum power point tracking (MPPT) under the ratedwind speed. The grid-side PWM inverter stabilizes the DC-busvoltage and accomplishes active and reactive decouplingcontrol by adjusting the current of the d-axis and q-axis of thegrid-side. The grid-side PWM inverter also controls thereactive power flow to the grid, usually at unity power factorcondition.A. Sensorless control based on PLLThe speed and position control is achieved throughsensorless vector control of the machine-side converter basedon all-digital phase-locked loop. The phase-locked loop isdesigned to control the frequency of the D-Q axis voltagethrough minimizing the difference of the output voltage phaseangle and the given voltage phase angle, until the outputvoltage phase angle tracks the given voltage phase angle. Asthe phase-locked loop has frequency closed-loop trackingmechanism, the generator voltage frequency and the anglebetween d-axis voltage and rotor flux can be measured withthis characteristic, then the generator speed and rotor positionangle can be derived [2]. The control accuracy is generallygood using this method, however some problems may occurwhen the generator operates at very low speed. The windpower system often works above the cut-in wind speed, so thismethod can be applied to wind power generation system.Fig. 2.The back-to-back PWM voltage converter vector control block diagramThe actual rotor position of PMSG is indicated in the D-Q coordinate system. The estimated location for ∧θ is the d q ∧∧− coordinate system, αβ is the stationary coordinate system, as shown in Fig. 3. As the rotor position of PMSG is estimated rather than measured in the sensorless vector control system, there exists an error θΔ between the actual rotor position θ and the estimated location ∧θ. At the same time, the back-EMF (electromotive force) generated by the rotor permanent magnets generates two d-axis and q-axis components in the estimated rotor position orientation coordinates, which are expressed as sd e ∧and sq e ∧respectively. Conventional PI controller can achieve zero error control, i.e. sd e ∧or θΔ can be adjusted to zero value. The PLL sensorless vector control schematic diagram is shown in Fig. 4, and the value of sd e ∧and sq e ∧can be obtained from (1).sd sd s sd dq sq sd sq sq s sq q d sd sq di u R i L L i e dt di u R i L L i e dt ωω∧∧∧∧∧∧⎧=+−−⎪⎪⎨⎪=+++⎪⎩(1)Fig. 3. Presumed rotating coordinate systemFig. 4. Principle of PLL based sensorless vector controlIf we ignore the current differential items in (1), then wehavesd s sd q sq sd sq sq s sq d sd ˆˆˆˆˆarctan(arctan(ˆˆˆˆˆu R i L i ee uR i L i ωθω−+Δ=−=−−− (2)where sd u , sq u , sd i and sq i are the d, q-axis components of the output voltage and current of the generator stator; d L q L and s R are the inductance and resistance of the stator; ω is thegenerator electrical angular velocity of the generator; "∧" indicates estimated value.Block diagram of sensorless vector control based on digital PLL is shown in Fig. 5. The back-EMF (electromotive force) value of the estimated rotating coordinates can be obtained by calculating the three-phase voltages and currents of the PMSGstator. The calculated angle difference θΔcan be used to estimate the angular velocity through the PI controller. Then the value of the estimated angle can be obtained by integral element. Generally, the speed has considerable fluctuations using this method. Therefore it will achieve a better estimation by adding a low-pass filter (LPF), as shown in Fig. 5.∧Fig. 5. Block diagram of sensorless vector control based on digital PLLB. Vector control of PMSGIn order to study the torque control of PMSG, it is necessary to establish a mathematical model. Because q-axis leads d-axis 90° in the D-Q coordinate system, the generator voltage equation can be expressed as [8]: sd sd s sd d sq sq sq sq sq q d sd di u R i L L i dt di u Ri L L i dt ωωωψ⎧=+−⎪⎪⎨⎪=+++⎪⎩(3) The significance of various physical quantities in (3) is the same as in (1).The generator electromagnetic torque equation can be expressed as:33()22e sq d q sd sq T p i p L L i i ψ=+− (4) where p is the number of generator pole pairs, and ψ is the magnetic flux.Based on the above mathematical model, the sensorless vector control program of PMSG is established, and its controlblock diagram is shown in Fig. 6.sa i sbi Fig. 6. Sensorless vector control block diagram of PMSGGenerator rotor position and speed which are estimated by sensorless algorithm can be used in vector control. Thereference value of motor torque can be obtained by the speedcontroller. The voltage reference of generator can also be gotby current controller, and then the control signals of rectifier switching device can be obtained by a set of PWM modulation algorithms. The position and speed of generator rotor which is necessary to vector control is obtained by sensorless algorithm.C. Single-phase grid-connected PLLFig. 7 shows the block diagram of the single-phase gird-connected PLL. In order to ensure that the converter outputvoltage is in the same phase with the output current, the PLLis used to achieve unity power factor control. At the sametime, the converter also provides the angle of the referencecurrent transformation [5].Fig. 7. The block diagram of the single-phase PLLThe transformation between orthogonal a-b and D-Q reference frames can be described by trigonometric relations, which are given in (5) and (6), and the rotating reference frame is shown in Fig. 8.Fig. 8. Definition of rotating reference frame⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡b a q d f f f f θθθθcos sin sin cos (5) ⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡q d b a f f f f θθθθcos sin sin cos (6)Active power and reactive power equations can beexpressed as:⎩⎨⎧−=+=d q q d qq d d i v i v Q i v i v P (7) If the phase voltage and q-axis coincide, then 0=d v andv v q =, active power and reactive power equations can besimplified as:||||q dP v i Q v i =⎧⎪⎨=−⎪⎩ (8) D. The vector control strategy of the grid-side inverterFor a three phase converter, simple PI compensators designed in a D-Q synchronous frame can achieve zero steady state error at the fundamental frequency, but this method is not applicable to single-phase power converter because there is only one phase variable available in a single-phase power converter, while the D-Q transformation needs at least two orthogonal variables.In order to construct the additional orthogonal phaseinformation from the original single-phase power converter,the imaginary orthogonal circuit is developed, as shown inFig. 9. The imaginary orthogonal circuit has exactly the samecircuit components and parameters, but the current b i and the voltage b e , maintain 90D phase shift with respect to their counterparts in the real circuit- a i and a e [6].Fig. 9. Real circuit and its imaginary orthogonal circuitFrom Fig. 9, the voltage equation can be expressed as:⎥⎦⎤⎢⎣⎡−−+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡b b a a b a b a v e v e L i i L R i i p 11001 (9) Transforming the voltage equations into the synchronousreference frame using (5) and (6), and considering 0=d v and v v q =, we have: ⎥⎦⎤⎢⎣⎡−+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−−−=⎥⎦⎤⎢⎣⎡||1//v e e L i i L R L R i i p qd q d q d ωω (10) To achieve decoupled control of active power and reactive power, the output voltage of the inverter in the synchronousreference frame can be expressed as:||)(1v i x L e d q +−=ω (11))(2q d i x L e ω+= (12)Substituting (11) and (12) into (10), system equations canbe rewritten as follows:⎥⎦⎤⎢⎣⎡+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡211001x x i i L R i i p q d q d (13) The active power and reactive power could be controlled by d i and q i respectively. Therefore, system control can be completed by current feedback loops as follows:))((211q q i i s k k x −+=∗(14)))((212d d i i sk k x −+=∗(15) Fig. 10 shows the control block diagram of the grid-sideinverter. It should be noted that the given active and reactive power should be set at two times of the desired values, because the imaginary circuit will not deliver any active andreactive power to the grid.θωFig. 10. The vector control block diagram of the grid-side inverterIV. S IMULATION RESULTSA simulation model in Matlab/Simulink is developed based on above theoretical analysis, and the system simulation block diagram is shown in Fig. 11.Fig. 11. The system simulation block diagramA. The simulation results of the machine-side converterIn the simulation model, the Reference speed represents the wind speed. At the beginning of the simulation (i.e. 0s), the generator speed is 4rpm and its input torque is -50Nm. At the time of 0.5s, the generator speed is 17 rpm and the input torque maintains at the value of -50Nm. At 1s, the generator speed maintains at 17 rpm and the input torque is -80Nm. The simulated waveforms are shown in Fig. 12, Fig. 13, Fig. 14, Fig. 15, respectively.It can be seen from Fig. 12 and Fig. 13, the error between the estimated rotor position angle and the actual measurement of the rotor position angle is very small in the steady state, there are some fluctuations in the dynamic response, but the rotor position angle is stabilized quickly.It can be seen from Fig. 14 and Fig. 15, there is a small error between the estimated and measured generator rotor speed at low speed. At high speed, however, the error is very small and can be ignored, and the transient response is very short. At the time 1s, the input torque increase affects thegenerator rotor speed slightly, and soon the transientdisappears.ˆ,(d e g )θθ()t sFig. 12. The estimated and measured rotor position angle(rad/s)θθ∧−(s)tFig. 13. The error of estimated and measured rotor position anglet(s)()nrpmFig. 14. The measured generator rotor speedt(s)t()esirpmnFig. 15. The estimated generator rotor speedThe simulation waveforms of the machine-side converterdemonstrate that the sensorless vector control algorithm canestimate the rotor angular position accurately, and the vectorcontrol strategy of the machine-side converter can realizegenerator speed control for the wind turbine to follow theoptimized power curve, i.e. MPPT when the wind speed isbelow rated wind speed.B. The simulation results of the grid-side inverterThe simulation results of the grid-side inverter is shown inFig. 16, Fig. 17 and Fig. 18 respectively.It can be seen from Fig. 16, when the generator outputtorque increases, the DC bus voltage is maintained constant.Fig. 17 shows that θu followsavvery well, and Fig. 18shows thatai followsavvery well.Fig. 16. The simulated DC voltageavuθuθFig. 17. The generator output A phase voltage and the grid voltage vectorangleFig. 18. The output voltage and current of the grid-side inverterFrom the simulation results of the grid-side inverter, it canbe seen that the single-phase PLL algorithm can accuratelytrack the grid-side voltage, and the vector control strategy ofthe grid-side inverter can stabilize the DC bus voltage, andcontrol the grid power factor.V. C ONCLUSIONThis research developed a power electronic converter for asmall direct-driven PMSG wind turbine using the back-to-back pulse-width modulation (PWM) topology. Thesimulation results demonstrate that1) The machine-side converter can control the generatorspeed and torque for the wind turbine to follow the optimizedpower curve, i.e. maximum power point tracking (MPPT)when the wind speed is below rated wind speed.2) The sensorless phase-locked loop (PLL) controlalgorithm can realize the vector control of the generator.3) The grid-side inverter control algorithm based on single-phase PLL can stabilize the DC bus voltage of the converter and control the grid power factor.VI. R EFERENCESPeriodicals:[1]De Tian, “The wind power technology status and development trend inthe world,” New Energy Industry, in press.[2]Ruzhen Dou, Lingyun Gu, Baotao Ning, “Sensorless control of thePMSM based on the PLL,” Electric Machines & Control Application, vol. 32, pp. 53-57, 2005.Books:[3]Qingding Guo, Yibiao Sun, Limei Wang, Modern permanent magnet ACservo motor system. China Electric Power Press, Beijing. In press.Papers from Conference Proceedings (Published):[4]S. Song, S. Kang, and N. Hahm, “Implementation and control of gridconnected AC-DC-AC power converter for variable speed wind energy conversion system,” in Proc. 2003 IEEE Applied Power Electronics Conference and Exposition, vol.1, pp.154 – 158.[5]M. Ciobotaru, R. Teodorescu and F. Blaabjerg, “A new single-phasePLL structure based on second order generalized integrator,” Record of IEEE PESC 2006, Korea, pp.1511-1516.[6]R. Zhang, M. Cardinal, P. Szczesny, M. Dame, “A grid simulator withcontrol of single-phase power converters in D-Q rotating frame,” Power Electronics Specialists Conference, vol.3, pp.1431 – 1436, 23-27 June 2002.[7]R. Esmail, L. Xu, D.K. Nichols, “A new control method of permanentmagnet generator for maximum power tracking in wind turbine application,” IEEE Power Engineering Society Meeting, vol.3, pp. 2090-2095, August 2005.[8]Yang Zhenkun, Liang Hui, “A DSP control system for the gridconnected inverter in wind energy conversion system,” IEEE ICEMS 2005 Electrical Machines and Systems, vol. 2, 2005, pp. 1050-1053, June 2005.[9]N V Suresh Kumar Srighakollapu, Partha Sarathi Sensarma, “Sensorlessmaximum power point tracking control in wind energy generation using permanent magnet synchronous generator,” Industrial Electronics 2008, 34th Annual Conference Of IEEE, Iecon , pp.2225-2230.Dissertations:[10]Cheng Lu, “The coordination control of dual PWM converter for VSCFwind power generation system,” MSc thesis, Graduate School of Chinese Academy of Sciences, Beijing, 2004.[11]Shenbing Wu, “Research on CSC-based small-scale grid-connectedwind power generation system”, MSc thesis, Hefei University of Technology, Hefei, 2009.VII. B IOGRAPHIESChunxue Wen received his BSc degree from Inner Mongolia University of Technology in 2001, MSc degree from Wuhan University in 2006, and PhD degree from the Institute of Electrical Engineering, Chinese Academy of Sciences in 2009. In 2010 he joined the Wind Energy Engineering Research Group at the University of Central Lancashire as a visiting researcher. He is currently working as a Lecturer at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. His research interests include power electronics, wind turbine control system, converters for wind turbines.Guojie Lu received his BSc degree from North China Electric Power University in 2006. He worked in Beijing Xinhuadu Special Transformer Company from 2007 to 2009, and was responsible for the technical service transformer. At present, he is registered as a postgraduate research student at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. His research area is wind turbine control system.The project aims to develop maximum power point tracking control algorithm for grid-connected small wind turbines.Peng Wang received his BSc degree from Taiyuan University of Technology in 2003, MSc degree from North China University of Technology in 2011. Since 2008, he has been working as a research assistant in Electrical Engineering at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. In 2010 he joined the Wind Energy Engineering Research Group at the University of Central Lancashire as a visiting student. His research areas are permanent-magnet synchronous generator control and wind energy engineering.Zhengxi Li received his PhD degree from the University of Science and Technology, Beijing. He is the Chair Professor in Power Electronics and Motor Drivers and Head of the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. He is also Vice President of North China University of Technology. His research interests include power electronics, high voltage power transmission and distribution, intelligent transportation and renewable energy. Xiongwei Liu was born in Xiangtan, China, in 1965. He received his BEng (Hons) degree from National University of Defense Technology, Changsha, in 1985, and his MSc (Distinction) and PhD degrees from Harbin Institute of Technology in 1988 and 1991 respectively.His employment experience included Northwestern Polytechnical University, Huaqiao University, Leeds Met University, University of Hertforshire and University of Central Lancashire. His research interests include wind energy engineering, renewable energy technologies, smart grid and microgrid, and intelligent energy management system.He received a research fellowship from Alexander-von-Humboldt Foundation of Germany, which allowed him to visit Ruhr University Bochum, as a research fellow for 18 months from 1993. In 1999 he was awarded a Bronze Medal by Huo Yingdong Education Funding Council and a Model Worker Medal by the Mayor of Quanzhou, China, due to his excellent contributions in higher education when he served as a professor at Huaqiao University. He received a research fellowship from Chinese Scholarship Council, which allowed him to visit Technical University Berlin as a senior research fellow for 6 months in 2000.Xiongwei Liu is currently working as Chair Professor of Energy and Power Management and Head of Wind Energy Engineering Research Group at the University of Central Lancashire.。
风力发电英文作文
风力发电英文作文Wind power generation is a clean and renewable energy source that harnesses the power of the wind to generate electricity. It is a sustainable alternative to traditional fossil fuels and has the potential to reduce greenhouse gas emissions and combat climate change.The use of wind turbines to capture the kinetic energyof the wind and convert it into electricity has beengrowing rapidly in recent years. Wind power generation has the advantage of being able to produce electricity without the release of harmful pollutants or greenhouse gases, making it an environmentally friendly energy source.One of the key benefits of wind power generation is its ability to provide electricity to remote and off-grid areas. Wind turbines can be installed in locations wheretraditional power infrastructure is not available, bringing electricity to communities that would otherwise havelimited access to energy.In addition to its environmental benefits, wind power generation also has the potential to create jobs and stimulate economic growth. The development, installation, and maintenance of wind turbines require skilled labor, creating employment opportunities in the renewable energy sector.Despite its many advantages, wind power generation also faces challenges. One of the main challenges is the intermittent nature of wind energy, as the wind does not blow consistently. This variability in wind speed can make it difficult to rely solely on wind power generation for electricity supply.In conclusion, wind power generation is a promising and sustainable energy source that has the potential to play a significant role in the transition to a low-carbon economy. With ongoing technological advancements and investment in wind energy infrastructure, it is likely to become an increasingly important part of the global energy mix.。
风力发电外文文献翻译中英文
风力发电外文翻译中英文英文Wind power in China – Dream or reality?HubacekAbstractAfter tremendous growth of wind power generation capacity in recent years, China now has 44.7 GW of wind-derived power. Despite the recent growth rates and promises of a bright future, two important issues - the capability of the grid infrastructure and the availability of backup systems - must be critically discussed and tackled in the medium term.The study shows that only a relatively small share of investment goes towards improving and extending the electricity infrastructure which is a precondition for transmitting clean wind energy to the end users. In addition, the backup systems are either geographically too remote from the potential wind power sites or currently financially infeasible. Finally, the introduction of wind power to the coal-dominated energy production system is not problem-free. Frequent ramp ups and downs of coal-fired plants lead to lower energy efficiency and higher emissions, which are likely to negate some of the emission savings from wind power.The current power system is heavily reliant on independentlyacting but state-owned energy companies optimizing their part of the system, and this is partly incompatible with building a robust system supporting renewable energy technologies. Hence, strategic, top-down co-ordination and incentives to improve the overall electricity infrastructure is recommended.Keywords: Wind power, China, Power grids, Back-up systems1. IntroductionChina 'wsi nd energy industry has experienced a rapid growth over the last decade. Since the promulgation of the first Renewable Energy Law in 2006, the cumulative installed capacity of wind energy amounted to 44.7 GW by the end of 2010 [1]. The newly installed capacity in 2010 reached 18.9 GW which accounted for about 49.5% of new windmills globally. The wind energy potential in China is considerable, though with differing estimates from different sources. According to He et al. [2], the exploitable wind energy potential is 600–1000 GW onshore and 100–200 GW offshore. Without considering the limitations of wind energy such as variable power outputs and seasonal variations, McElroy et al. [3] concluded that if the Chinese government commits to an aggressive low carbon energy future, wind energy is capable of generating 6.96 million GWh of electricity by 2030, which is sufficient to satisfy China ' selectricity demand in 2030.The existing literature of wind energy development in China focuses on several discussion themes. The majority of the studies emphasize the importance of government policy on the promotion of wind energy industry in China [4], [5], [6], [7]. For instance, Lema and Ruby [8] compared the growth of wind generation capacity between 1986 and 2006, and addressed the importance of a coordinated government policy and corresponding incentives. Several studies assessed other issues such as the current status of wind energy development in China [9]; the potential of wind power [10]; the significance of wind turbine manufacturing [11]; wind resource assessment [5]; theapplication of small-scale wind power in rural areas [12]; clean development mechanism in the promotion of wind energy in China [4], social, economic and technical performance of wind turbines [13] etc.There are few studies which assess the challenge of grid infrastructure in the integration of wind power. For instance, Wang [14] studied grid investment, grid security, long-distance transmission and the difficulties of wind power integration at present. Liao et al. [15] criticised the inadequacy of transmission lines in the wind energy development. However, webelieve that there is a need to further investigate these issues since they are critical to the development of wind power in China. Furthermore, wind power is not a stand-alone energy source; it needs to be complemented by other energy sources when wind does not blow. Although the viability and feasibility of the combination of wind power with other power generation technologies have been discussed widely in other countries, none of the papers reviewed the situation in the Chinese context. In this paper, we discuss and clarify two major issues in light of the Chinese wind energy distribution process: 1) the capability of the grid infrastructure to absorb and transmit large amounts of wind powered electricity, especially when these wind farms are built in remote areas; 2) the choices and viability of the backup systems to cope with the fluctuations of wind electricity output.2. Is the existing power grid infrastructure sufficient?Wind power has to be generated at specific locations with sufficient wind speed and other favourable conditions. In China, most of the wind energy potential is located in remote areas with sparse populations and less developed economies. It means that less wind powered electricity would be consumed close to the source. A large amount of electricity has to be transmittedbetween supply and demand centres leading to several problems associated with the integration with the national power grid system, including grid investment, grid safety and grid interconnection.2.1.P ower grid investmentAlthough the two state grid companies-(SGCC) State Grid Corporation of China and (CSG) China Southern Grid - have invested heavily in grid construction, China 'pso wer grid is still insufficient to cope with increasing demand. For example, some coal-fired plants in Jiangsu, which is one of the largest electricity consumers in China, had to drop the load ratio to 60 percent against the international standard of 80 percent due to the limited transmission capacity [16]. This situation is a result of an imbalanced investment between power grid construction and power generation capacity. For example, during the Eighth Five-Year Plan, Ninth Five-Year Plan and Tenth Five-Year Plan,1 power grid investments accounted for 13.7%, 37.3% and 30% of total investment in the electricity sector, respectively. The ratio further increased from 31.1% in 2005 to 45.94% in 2008, the cumulative investment in the power grid is still significantly lower than the investments in power generation [17]. Fig. 1 gives a comparison of the ratios ofaccumulative investments in power grid and power generation in China, the US, Japan, the UK and France since 1978. In most of these countries, more than half of the electric power investment has been made on grid construction. By contrast, the ratio is less than 40% in China.According to the Articles 14 and 21 of the Chinese Renewable Energy Law, the power grid operators are responsible for thegrid connection of renewable energy projects. Subsidies are given subject to the length of the grid extension with standard rates. However, Mo [18] found that the subsidies were only sufficient to compensate for capital investment and corresponding interest but excluding operational and maintenance costs.Again, similar to grid connection, grid reinforcement requires significant amounts of capital investment. The Three Gorges power plant has provided an example of large-scale and long-distance electricity transmission in China. Similar to wind power, hydropower is usually situated in less developed areas. As a result, electricity transmission lines are necessaryt o deliver the electricity to the demand centres where the majority are located; these are the eastern coastal areas and the southern part of China. According to SGCC [19], the gridreinforcement investment of the Three Gorges power plants amounted to 34.4 billion yuan (about 5 billion US dollars). This could be a lot higher in the case of wind power due to a number of reasons. First, the total generating capacity of Three Gorges project is approximately 18.2 GW at this moment and will reach 22.4 GW when fully operating [20], whilst the total generating capacity of the massive wind farms amount to over 100 GW. Hence, more transmission capacities are absolutely necessary. Second, the Three Gorges hydropower plant is located in central China. A number of transmission paths are available, such as the 500 kV DC transmission lines to Shanghai (with a length of 1100 km), Guangzhou (located in Guangdong province, with a length of 1000 km) and Changzhou (located in Jiangsu province, with a length of 1000 km) with a transmission capacity of 3 GW each and the 500 kV AC transmission lines to central China with transmission capacity of 12 GW. By contrast, the majority of wind farm bases, which are located in the northern part of China, are far away from the load centres. For example, Jiuquan located in Gansu has a planned generation capacity of 20 GW. The distances from Jiuquan to the demand centres of the Central China grid and the Eastern China grid are 1500 km and 2500 km, respectively. For Xinjiang, the distances are even longer at 2500 km and 4000 km,respectively. As a result, longer transmission lines are required. Fig. 2 depicts the demand centres and wind farms in detail.2.2.Grid safetyThe second problem is related to grid safety. The large-scale penetration of wind electricity leads to voltage instability, flickers and voltage asymmetry which are likely to cause severe damage to the stability of the power grid [21]. For example, voltage stability is a key issue in the grid impact studies of wind power integration. During the continuous operation of wind turbines, a large amount of reactive power is absorbed, which lead to voltage stability deterioration [22]. Furthermore, the significant changes in power supply from wind might damage the power quality [23]. Hence, additional regulation capacity would be needed. However, in a power system with the majority of its power from base load provider, the requirements cannot be met easily [24]. In addition, the possible expansion of existing transmission lines would be necessary since integration of large-scale wind would cause congestion and other grid safety problems in the existing transmission system. For example, Holttinen [23] summarized the majorimpacts of wind power integration on the power grid at the temporal level (the impacts of power outputs at second, minute to year level on the power grid operation) and the spatial level (the impact on local, regional and national power grid). Besides the impacts mentioned above, the authors highlight other impacts such as distribution efficiency, voltage management and adequacy of power on the integration of wind power [23].One of the grid safety problems caused by wind power is reported by the (SERC) State Electricity Regulatory Commission [25]. In February and April of 2011, three large-scale wind power drop-off accidents in Gansu (twice) and Hebei caused power losses of 840.43 MW, 1006.223 MW and 854 MW, respectively, which accounted for 54.4%, 54.17% and 48.5% of the total wind powered outputs. The massive shutdown of wind turbines resulted in serious operational difficulties as frequency dropped to 49.854 Hz, 49.815 Hz and 49.95 Hz in the corresponding regional power grids.The Chinese Renewable Energy Law requires the power grid operators to coordinate the integration of windmills and accept all of the wind powered electricity. However, the power grid companies have been reluctant to do so due to the above mentioned problems as well as technical and economic reasons. For instance, more than one third of the wind turbines in China, amounting to 4 GW capacity, were not connected to the power grid by the end of 2008 [17]. Given that the national grid in China is exclusively controlled by the power companies – SGCC and CSG - the willingness ofthese companies to integrate wind energy into the electricity generation systems is critical.2.3.T he interconnection of provincial and regional power gridsThe interconnection of trans-regional power grids started at the end of 1980s. A (HVDC) high voltage direct current transmission line was established to link the Gezhouba2 dam with Shanghai which signifies the beginning of regional power grids interconnection. In 2001, two regional power grids, the North China Power Grid and Northeast China Power Grid were interconnected. This was followed by the interconnection of the Central China Power Grid and the North China Power Grid in 2003. In 2005, two other interconnection agreements were made between the South China Power Grid with North, Northeast and Central China Power Grid, and the Northwest China Power Grid and the Central China Power Grid. Finally, in 2009, the interconnection of Central China Power Grid and the East China Power Grid was made. In today ' s China, the Chinesepower transmission systems are composed of 330 kV and 500 kV transmission lines as the backbone and six interconnected regional power grids and one Tibet power grid [26].It seems that the interconnectivity of regional power grids would help the delivery of wind powered outputs from wind-rich regions todemand centres. However, administrative and technical barriers stillexist. First, the interconnectivity among regions is always considered as a backup to contingencies, and could not support the large-scale, long-distance electricity transmission [27]. In addition, the construction of transmission systems is far behind the expansion of wind power. The delivery of large amounts of wind power would be difficult due to limited transmission capacity. Furthermore, the quantity of inter-regional electricity transmission is fixed [27]. Additional wind power in theinter-regional transmission might have to go through complexadministrative procedures and may result in profit reductions of conventional power plants.3. Are the backup systems geographically available and technically feasible?Power system operators maintain the security of power supply by holding power reserve capacities in operation. Although terminologies used in the classification of power reserves vary among countries [28], power reserves are always used to keep the production and generation in balance under a range of circumstances, including power plant outages, uncertain variations in load and fluctuations in power generations (such as wind) [29]. As wind speed varies on all time scales (e.g. from seconds to minutes and from months to years), the integration of fluctuating wind power generation induces additional system balancing requirements on the operational timescale [29].A number of studies have examined the approaches to stabilize the electricity output from wind power plants. For example, Belanger and Gagnon [30] conducted a study on the compensation of wind power fluctuations by using hydropower in Canada. Nema et al. [31] discussed the application of wind combined solar PV power generation systems and concluded that the hybrid energy system was a viable alternative to current power supply systems in remote areas. In China, He et al. [2]investigated the choices of combined power generation systems. The combinations of wind-hydro, wind-diesel, wind-solar and wind-gas power were evaluated respectively. They found that, for instance, the wind-diesel hybrid systems were used at remote areas and isolated islands. This is because the wind-diesel hybrid systems have lower generation efficiency and higher generation costs compared to other generation systems. Currently, the wind-solar hybrid systems are not economically viable for large-scale application; thus, these systems have either been used at remote areas with limited electricity demand (e.g. Gansu Subei and Qinghai Tiansuo) or for lighting in some coastal cities [2]. Liu et al. [32] adopted the EnergyPLAN model to investigate the maximum wind power penetration level in the Chinese power system. The authors derived a conclusion that approximately 26% of national power demand could be supplied by wind power by the end of 2007. However, theauthors fail to explain the provision of power reserves at different time scales due to wind power integration.Because of the smoothing effects of dispersing wind turbines at different locations (as exemplified by Drake and Hubacek [33] for theU.K., Roques [34] for the E.U. and Kempton et al. [35] for the U.S.), the integration of wind power has a very small impact on the primary reserves which are available from seconds to minutes [36]. However, the increased reserve requirements are considerable on secondary reserves (available within 10 –15 min) which mainly consist of hydropower plants and gas turbine power plants [29]. Besides, the long-term reserves, which are used to restore secondary reserves after a major power deficit, will be in operation to keep power production and consumption in balance for a longer timescale (from several minutes to several hours). In the following subsection, we examine the availability of power plants providing secondary and long-term reserves and investigate the viability of energy storage system in China.中文中国的风力发电–梦想还是现实？胡巴切克摘要经过近几年风力发电能力的巨大增长，中国现在拥有 44.7 吉瓦的风力发电。
风力发电机英语作文加翻译
风力发电机英语作文加翻译Use of wind turbines, wind energy is continuously put into power for our household use. This article uses the low-speed rated at 5KW wind turbine permanent magnet, such a small amount of instability due to wind turbines, it began to turn from their work, to convert wind energy into mechanical energy, and then the mechanical energy into electrical energy, it outputs voltage and current is constantly changing, the controller must be rectified by the regulator, into DC and then to the battery charging, wind turbines will generate electricity into chemical energy. Then there is the power protection circuit of the inverter, the battery in the chemical energy into AC 220V power. If it is only required to output DC electrical voltage to the corresponding electrical voltage and can be used. This ensures stable use. This article is complete with a thyristor trigger circuit to the rectifier circuit; inverter power supply selection switch controller SG3524 integrated inverter to achieve the conversion process使用风力涡轮机，风力发电将持续用于我们的家庭使用。
风力发电技术英语翻译
Wind Power Generation TechnologyWind is very important and reserves of energy, it is safe, clean, and can provide abundant energy, stabilityof the stream. Now, use wind power has become the main form of wind, the world's attention, and the fastest. Wind energy technology is a high-tech; it relates more than a dozen of subjects, including meteorology,aerodynamics, structural mechanics, computer technology, electronic control technology, material science,chemistry, electrical engineering, electrical engineering, so the difficulty of a system technology may beyondthe difficulty of space technology.First, The division of wind energy technologies:Wind energy technology is divided into large-scale wind power technology and small and medium sizedwind power technology, although both are wind energy technology, working principles are the same, the twoindustries are completely different: specific performance of the "policy orientation is different in differentmarkets, different applications, applied technology is different, totally belong to the same kinds of industries inthe two sectors. Therefore, in China machinery industry meeting on the wind to large wind power and windpower to distinguish between small and medium treated separately. In addition, to meet different market needs,extending from the wind and solar technology has not only promoted the development of small wind powertechnology, but also for the small wind power opens up new markets.1. Large-scale wind power technology:The technology of large-scale wind power in China still has a certain gap between international.The technology of large-scale wind power technology originated in Denmark and some other Europeancountries, the wind power industry propelled by the government, because of the local wind resource-rich,large-scale wind power technology and equipment ahead of the international development. Our governmenthas also started to boost the development of large-scale wind power technology, and a range of policies toguide industry development. Large-scale wind power technology are for the large-scale wind turbine design,wind turbine applications for large area on the very strict environmental requirements are applied to limitedresources, wind energy resource-rich wind field, to accept a variety of perennial bad environment thatsomething was the complex nature of the environment, high demands on the technology up on the line.Currently large-scale wind power technology in general is not yet ripe, the core technology of large-scale windpower still rely on foreign, national policy guidance to the domestic wind power project launched in variousplaces, like crazy, all over look forward to slice.Worthy of the name "mad electricity" through the wind beganto Negative effect and Precaution policy. Although wind power projects have been started, but more ascomplementary type, complete with independent intellectual property rights of large-scale wind powersystems technology and core technology few. The test environment needs to have been a large-scale windpower technology to mature. In addition, the large-scale wind power generation technology and networktechnology has also improved a number of issues still restrict the development of large-scale wind powertechnology.2. The technology of small wind power:The technology of small wind power in China could compare with the international technology.In 1970s, the small wind power technology in China had been developed which has wind resources for abetter situation, including Inner Mongolia, Xinjiang areas, the first small wind power technology is widelyused in power transmission project to the Township for a one of farmers and herdsmen household powersupply, continuously updated as the technology improvement and development, not only alone but also withthe combination of complementary optical has been widely used in distributed independent power supply.These years as Chinese exports of small and medium wind steadily. Internationally, China's small and mediumsized wind power technology and wind and solar technology have leapt to international leadership.Small wind power technology is mature and relatively small by natural resource constraints, distributedindependent power as a significant effect not only connected, but also the formation of more stable andreliable combination of optical complementary technologies scenery Moreover, technology is completelyself-localization. Both from a technical or price in the international arena are very competitive; withinternational has now started a small wind power in China brand; "wall flower wall Hong" has intensified. Inthe country's most technical advantages and competitiveness of small and medium wind power has alwaysbeen forgotten by the government and policy in a corner of reasons, in the early states has been to locate thesmall and medium sized wind power in Inner Mongolia, Xinjiang, farmers and herdsmen in remote areas touse and return into the agricultural class, low cost, shoddy, low-performance reliability, security, no security ofland mostly sparsely populated areas, most of the domestic market are subject to loss of reliability of largeprice war; in people subconsciously form a poor understanding of So get national attention and development.Domestic small wind power technology in the "low wind start, low wind speed generation, pitch moment,multiple protection, and a series of technical attention by the international market and international clientsunanimously approved, has a leading position. Moreover, the smalland medium Wind power technology isultimately distributed independent power supply to meet end-market, rather than large-scale wind powergeneration and network technologies to meet the domestic monopoly market, technology, update rate must beadapted to a broad and rapidly growing market.3. wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar EnergyTechnology, combines a variety of applications of new technology, and it covers many areas, the wide rangeof applications, technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature, mostlarge-scale and industrial development of the industry, separate and individual solar wind has its drawbacks ofdevelopment, but both wind and solar power complementary combined to realize the two new configurationof energy in natural resources, the technical programs of integration, performance and price compared toaspects of the new energy source for the most reasonable, not only reduces the demand to meet under the sameunit cost and expand the scope of application of the market, also increases the reliability of the product.In addition: solar and wind power are both new energy, solar energy than the wind started to be late morethan 30 per solar PV / W by the general public about the price of recognition can be converted to a 15% rate;while the price of small wind power conversion rate is only 1/5-1/6 of the same 60% -80%, only the low priceWorse still suppressed, photoelectric production of pollution on the environment greater than wind power,than substantial development in wind energy, this comparison contrast twist of meditation ......, if people usethe energy from the point of view, our goal is to meet the electricity from wind power generating capacity tomeasure the cost of solar energy economy than many .Wind, solar and wind power integration advantages, not only for the "energy saving, emission reduction,"opened up new horizons for the application of science to meet human needs, for the world to open a fourthrevolution.Second，Wind power has three kinds of operation mode:one is independent operation mode, usually a small wind generators to one or a few families to providepower, storage battery energy, to ensure the electricity without wind, Second is the wind turbines and otherpower mode (such as engine power), combining to a unit or an village or an island power supply, Three iswind power into conventional power operate and to provide electric power grid, is often a wind tens orhundreds of sets installed wind generators, this is the main development direction of windpower.Wind power system in the two main parts is wind machine and generators. Wind turbines to change fromadjusting technique, plasma generator toward VSCF technology, this is the development trend of wind powertechnology is the core technology nowadays wind turbines. The following simple introduction of this tworespects.1 the change of wind plasma from regulationWind turbines impeller, will capture the wind by converting wind effects on the mechanical wheeltorque.Change is the change from adjustment with vertical axis wind leaf surface of Angle, thus affecting theforce and the blade, when the wind resistance increases, the output power of the fan is kept constant poweroutput. By regulating mode, fan from the output power curve is smooth. In the rated wind leaf Angle of attack,controller will be placed near zero, do not change, approximate distance equal to adjust for pulp. In the ratedwind above, variable structure control function from pulp, adjust the blade Angle of attack, the output powercontrol in near ratings. Change from the wind plasma starting from wind speed is set slurry machinedowntime at low impact stress relative ease. The normal work, is mainly adopts power control, in practicalapplications, power and speed is directly proportional to the set. Small changes will cause the wind changes ofwind. Due to the change of wind from pulp by adjusting the impact than other wind from small, can reducematerial utilization rate, reduce overall weight. And the change of wind fromaccommodation type at lowspeed, can make the blades, keep good Angle of attack than accommodation type stall wind turbines havebetter energy output, therefore is suitable for low average speed of the region.Change from another advantage of regulation, when the winds reach a certain value, stall type of windand downtime, must from type machine can gradually changes to the wind load without a blades of openmode, avoid wing, increase of wind turbine.Change is to adjust the defect is sensitive response requires gusts. Because the wind accommodation typestall fan vibration power pulse are small, and accommodation type from wind turbines is bigger, especially forthe change from the constant speed windmills way, this kind of circumstance, this does not require moreobvious change in the fan is the response speed of wind system to fast enough, can reduce this phenomenon.Third, the development of wind energy technology requires constantinnovation:At present, China's wind energy development in technological innovation is still very weak, the lack ofcore technologies with independent intellectual property. Thus, much would import technology fromabroad.Although the arrival of knowledge economy era, all countries take full advantage of global resources andinternational cooperation through the introduction of technology to bridge the gap and improvecompetitiveness. But if there is no capability of independent innovation, not know what the introduction ofadvanced technologies, are not able to absorb the future, can not carry out another record, which is on the onehand; on the other hand, the core technology is the introduction of foreign countries cannot, and must be relyon innovation to master the core technology; Moreover, the domestic policy of independent innovation oftechnology needs to supporting, guiding, supporting, with the core technology of wind energy products to beincreasing support, such a "wall flower wall incense" situation can be change, innovation and power can comefrom constant innovation.In short: the wind power industry continuing to creating in a single generation from wind energytechnology to power the various areas of need ,its additional products have emerged such as: street, landscape,traffic control, communication, irrigation, planting, breeding, sea water desalination , fire, alarm, islands,mountains and so on. Shows the development of wind energy in this new industry can be brought aboutnumerous development and transformation of traditional industries, but the application of wind energytechnology in various fields has become the industry's benchmark. World revolution will be caused by windenergy technology from the New Energy and Industrial revolution.风力发电技术风能是非常重要并储量巨大的能源，它安全、清洁、充裕，能提供源源不绝，稳定的能源。
wind power generation作文及翻译风力发电
wind power generation作文及翻译风力发电In recent years, as a renewable clean energy, wind energy has been paid more and more attention all over the world. In recent years, the world wind power has been taking the wind turbine as the core to develop the key equipment of wind turbine power generation system. In the past few years, the localization of design and manufacturing problems has been the bottleneck of China's wind power generation.With the development of localization of wind power equipment in China The research and design of Zhanhe asynchronous generator has always been an urgent problem to be solved in the power industry. With the support and pro motion of the relevant preferential policies of the state, the rapid development of wind power industry in China has reached. With the expansion of the total installed capacity of wind power in kilowatt scale, due to the contingency a nd randomness of wind power, the impact of wind power on the stability of power grid can not be ignored, so the wind turbine was established The asynchronous model of group variable capacity makes the stability of wind turbine i n the wind power generation system can be analyzed and treated by the method similar to synchronous motor.The asynchronous wind generator is an important model of wind power generation. The simulation of asynchronous generator based on SPS module is of great significance because of its simple structure, lowprice and no strict control and control network equipment It is easier to connect with the power grid, but its speed can be changed to a certain extent, which will be able to absorb the transient process of wind energy. However, Xu Jizhu asynchronous generator grid is exciting and increases the demand for reactive power.Based on the requirements of asynchronous wind turbine control system, according to the actual operation model of wind turbine, and using Matlab/Simulink The simulation results are basically consistent with the actual operation of wind turbines.翻译：近年来，风能作为一种可再生的清洁能源日益受到世界各国的广泛关注，使得近几年世界风电一直以风电机组为核心发展风电机组发电系统的关键设备，在过去的几年里，设计和制造问题的本地化一直是中国风力发电的瓶颈，随着我国风力发电设备国产化工作的开展和异步发电机的研究与设计一直是电力行业迫切需要解决的问题，在国家相关优惠政策的支持和推动下，我国风电事业的快速发展已经达到了随着风电总装机容量千瓦规模的扩大，由于风电的偶然性和随机性，风电对电网稳定性的影响已不容忽视，建立了风电机组变容量异步模型，使风电机组在风力发电系统中的稳定性可以用类似于同步电机来分析处理它们的异步风力发电机是风力发电的一个重要模型，基于SPS模块的异步发电机仿真具有重要意义，因为其结构简单、价格低廉，而且不需要严格的控制和控制网络设备，可以更容易地与电网连接，但其转速可以在一定程度上改变，将能够吸收风能的暂态过程然而，许继柱异步发电机电网令人振奋，增加了电网对无功功率的需求，基于异步风电机组控制系统的要求开发了，根据建立的风力发电机组实际运行模型，并利用MATLAB/SIMULINK对其过程进行了仿真，仿真结果与实际运行的风电机组基本一致。
风力发电英文作文
风力发电英文作文英文：Wind power is a renewable energy source that has gained popularity in recent years. It involves the use of wind turbines to generate electricity, which can then be used to power homes, businesses, and even entire cities. One of the benefits of wind power is that it is clean and does not produce any harmful emissions, unlike fossil fuels.Another advantage of wind power is that it is cost-effective. While the initial investment in wind turbines can be high, the cost of producing electricity from wind power is much lower than that of traditional power sources. This is because wind is a free and abundant resource, and once the turbines are installed, the cost of producing electricity is relatively low.In addition to being a clean and cost-effective energy source, wind power also has the potential to create jobsand stimulate economic growth. The construction and maintenance of wind turbines require skilled workers, and the development of wind farms can create new opportunities for businesses and entrepreneurs.However, there are also some challenges associated with wind power. One of the biggest challenges is that wind is an intermittent energy source, meaning that it is not always available. This can make it difficult to rely solely on wind power to meet energy needs. Additionally, wind turbines can be noisy and can have negative impacts on wildlife and their habitats.Despite these challenges, wind power is still a promising energy source that has the potential to play a significant role in our transition to a more sustainable future.中文：风力发电是一种可再生能源，近年来受到了广泛的关注。
风力发电外文文献翻译中英文
风力发电外文翻译中英文英文Wind power in China – Dream or reality?HubacekAbstractAfter tremendous growth of wind power generation capacity in recent years, China now has 44.7 GW of wind-derived power. Despite the recent growth rates and promises of a bright future, two important issues - the capability of the grid infrastructure and the availability of backup systems - must be critically discussed and tackled in the medium term.The study shows that only a relatively small share of investment goes towards improving and extending the electricity infrastructure which is a precondition for transmitting clean wind energy to the end users. In addition, the backup systems are either geographically too remote from the potential wind power sites or currently financially infeasible. Finally, the introduction of wind power to the coal-dominated energy production system is not problem-free. Frequent ramp ups and downs of coal-fired plants lead to lower energy efficiency and higher emissions, which are likely to negate some of the emission savings from wind power.The current power system is heavily reliant on independently acting but state-owned energy companies optimizing their part of the system, and this is partly incompatible with building a robust system supportingrenewable energy technologies. Hence, strategic, top-down co-ordination and incentives to improve the overall electricity infrastructure is recommended.Keywords: Wind power, China, Power grids, Back-up systems1. IntroductionChina’s wind energy industry has exper ienced a rapid growth over the last decade. Since the promulgation of the first Renewable Energy Law in 2006, the cumulative installed capacity of wind energy amounted to 44.7 GW by the end of 2010 [1]. The newly installed capacity in 2010 reached 18.9 GW which accounted for about 49.5% of new windmills globally. The wind energy potential in China is considerable, though with differing estimates from different sources. According to He et al. [2], the exploitable wind energy potential is 600–1000 GW onshore and 100–200 GW offshore. Without considering the limitations of wind energy such as variable power outputs and seasonal variations, McElroy et al. [3] concluded that if the Chinese government commits to an aggressive low carbon energy future, wind energy is capable of generating 6.96 million GWh of electricity by 2030, which is sufficient to satisfy China’s electricity demand in 2030.The existing literature of wind energy development in China focuses on several discussion themes. The majority of the studies emphasize the importance of government policy on the promotion of wind energyindustry in China [4], [5], [6], [7]. For instance, Lema and Ruby [8] compared the growth of wind generation capacity between 1986 and 2006, and addressed the importance of a coordinated government policy and corresponding incentives. Several studies assessed other issues such as the current status of wind energy development in China [9]; the potential of wind power [10]; the significance of wind turbine manufacturing [11]; wind resource assessment [5]; the application of small-scale wind power in rural areas [12]; clean development mechanism in the promotion of wind energy in China [4], social, economic and technical performance of wind turbines [13] etc.There are few studies which assess the challenge of grid infrastructure in the integration of wind power. For instance, Wang [14] studied grid investment, grid security, long-distance transmission and the difficulties of wind power integration at present. Liao et al. [15] criticised the inadequacy of transmission lines in the wind energy development. However, we believe that there is a need to further investigate these issues since they are critical to the development of wind power in China. Furthermore, wind power is not a stand-alone energy source; it needs to be complemented by other energy sources when wind does not blow. Although the viability and feasibility of the combination of wind power with other power generation technologies have been discussed widely in other countries, none of the papers reviewed thesituation in the Chinese context. In this paper, we discuss and clarify two major issues in light of the Chinese wind energy distribution process: 1) the capability of the grid infrastructure to absorb and transmit large amounts of wind powered electricity, especially when these wind farms are built in remote areas; 2) the choices and viability of the backup systems to cope with the fluctuations of wind electricity output.2. Is the existing power grid infrastructure sufficient?Wind power has to be generated at specific locations with sufficient wind speed and other favourable conditions. In China, most of the wind energy potential is located in remote areas with sparse populations and less developed economies. It means that less wind powered electricity would be consumed close to the source. A large amount of electricity has to be transmitted between supply and demand centres leading to several problems associated with the integration with the national power grid system, including grid investment, grid safety and grid interconnection.2.1. Power grid investmentAlthough the two state grid companies-(SGCC) State Grid Corporation of China and (CSG) China Southern Grid - have invested heavily in grid construction, China’s powe r grid is still insufficient to cope with increasing demand. For example, some coal-fired plants in Jiangsu, which is one of the largest electricity consumers in China, had to drop the load ratio to 60 percent against the international standard of 80percent due to the limited transmission capacity [16]. This situation is a result of an imbalanced investment between power grid construction and power generation capacity. For example, during the Eighth Five-Year Plan, Ninth Five-Year Plan and Tenth Five-Year Plan,1 power grid investments accounted for 13.7%, 37.3% and 30% of total investment in the electricity sector, respectively. The ratio further increased from 31.1% in 2005 to 45.94% in 2008, the cumulative investment in the power grid is still significantly lower than the investments in power generation [17]. Fig. 1 gives a comparison of the ratios of accumulative investments in power grid and power generation in China, the US, Japan, the UK and France since 1978. In most of these countries, more than half of the electric power investment has been made on grid construction. By contrast, the ratio is less than 40% in China.According to the Articles 14 and 21 of the Chinese Renewable Energy Law, the power grid operators are responsible for the grid connection of renewable energy projects. Subsidies are given subject to the length of the grid extension with standard rates. However, Mo [18] found that the subsidies were only sufficient to compensate for capital investment and corresponding interest but excluding operational and maintenance costs.Again, similar to grid connection, grid reinforcement requires significant amounts of capital investment. The Three Gorges power planthas provided an example of large-scale and long-distance electricity transmission in China. Similar to wind power, hydropower is usually situated in less developed areas. As a result, electricity transmission lines are necessary to deliver the electricity to the demand centres where the majority are located; these are the eastern coastal areas and the southern part of China. According to SGCC [19], the grid reinforcement investment of the Three Gorges power plants amounted to 34.4 billion yuan (about 5 billion US dollars). This could be a lot higher in the case of wind power due to a number of reasons. First, the total generating capacity of Three Gorges project is approximately 18.2 GW at this moment and will reach 22.4 GW when fully operating [20], whilst the total generating capacity of the massive wind farms amount to over 100 GW. Hence, more transmission capacities are absolutely necessary. Second, the Three Gorges hydropower plant is located in central China. A number of transmission paths are available, such as the 500 kV DC transmission lines to Shanghai (with a length of 1100 km), Guangzhou (located in Guangdong province, with a length of 1000 km) and Changzhou (located in Jiangsu province, with a length of 1000 km) with a transmission capacity of 3 GW each and the 500 kV AC transmission lines to central China with transmission capacity of 12 GW. By contrast, the majority of wind farm bases, which are located in the northern part of China, are far away from the load centres. For example, Jiuquan locatedin Gansu has a planned generation capacity of 20 GW. The distances from Jiuquan to the demand centres of the Central China grid and the Eastern China grid are 1500 km and 2500 km, respectively. For Xinjiang, the distances are even longer at 2500 km and 4000 km, respectively. As a result, longer transmission lines are required. Fig. 2 depicts the demand centres and wind farms in detail.2.2. Grid safetyThe second problem is related to grid safety. The large-scale penetration of wind electricity leads to voltage instability, flickers and voltage asymmetry which are likely to cause severe damage to the stability of the power grid [21]. For example, voltage stability is a key issue in the grid impact studies of wind power integration. During the continuous operation of wind turbines, a large amount of reactive power is absorbed, which lead to voltage stability deterioration [22]. Furthermore, the significant changes in power supply from wind might damage the power quality [23]. Hence, additional regulation capacity would be needed. However, in a power system with the majority of its power from base load provider, the requirements cannot be met easily [24]. In addition, the possible expansion of existing transmission lines would be necessary since integration of large-scale wind would cause congestion and other grid safety problems in the existing transmission system. For example, Holttinen [23] summarized the majorimpacts of wind power integration on the power grid at the temporal level (the impacts of power outputs at second, minute to year level on the power grid operation) and the spatial level (the impact on local, regional and national power grid). Besides the impacts mentioned above, the authors highlight other impacts such as distribution efficiency, voltage management and adequacy of power on the integration of wind power [23].One of the grid safety problems caused by wind power is reported by the (SERC) State Electricity Regulatory Commission [25]. In February and April of 2011, three large-scale wind power drop-off accidents in Gansu (twice) and Hebei caused power losses of 840.43 MW, 1006.223 MW and 854 MW, respectively, which accounted for 54.4%, 54.17% and 48.5% of the total wind powered outputs. The massive shutdown of wind turbines resulted in serious operational difficulties as frequency dropped to 49.854 Hz, 49.815 Hz and 49.95 Hz in the corresponding regional power grids.The Chinese Renewable Energy Law requires the power grid operators to coordinate the integration of windmills and accept all of the wind powered electricity. However, the power grid companies have been reluctant to do so due to the above mentioned problems as well as technical and economic reasons. For instance, more than one third of the wind turbines in China, amounting to 4 GW capacity, were not connectedto the power grid by the end of 2008 [17]. Given that the national grid in China is exclusively controlled by the power companies –SGCC and CSG - the willingness of these companies to integrate wind energy into the electricity generation systems is critical.2.3. The interconnection of provincial and regional power gridsThe interconnection of trans-regional power grids started at the end of 1980s. A (HVDC) high voltage direct current transmission line was established to link the Gezhouba2 dam with Shanghai which signifies the beginning of regional power grids interconnection. In 2001, two regional power grids, the North China Power Grid and Northeast China Power Grid were interconnected. This was followed by the interconnection of the Central China Power Grid and the North China Power Grid in 2003. In 2005, two other interconnection agreements were made between the South China Power Grid with North, Northeast and Central China Power Grid, and the Northwest China Power Grid and the Central China Power Grid. Finally, in 2009, the interconnection of Central China Power Grid and the East China Power Grid was made. In today’s China, the Chinese power transmission systems are composed of 330 kV and 500 kV transmission lines as the backbone and six interconnected regional power grids and one Tibet power grid [26].It seems that the interconnectivity of regional power grids would help the delivery of wind powered outputs from wind-rich regions todemand centres. However, administrative and technical barriers still exist. First, the interconnectivity among regions is always considered as a backup to contingencies, and could not support the large-scale, long-distance electricity transmission [27]. In addition, the construction of transmission systems is far behind the expansion of wind power. The delivery of large amounts of wind power would be difficult due to limited transmission capacity. Furthermore, the quantity of inter-regional electricity transmission is fixed [27]. Additional wind power in the inter-regional transmission might have to go through complex administrative procedures and may result in profit reductions of conventional power plants.3. Are the backup systems geographically available and technically feasible?Power system operators maintain the security of power supply by holding power reserve capacities in operation. Although terminologies used in the classification of power reserves vary among countries [28], power reserves are always used to keep the production and generation in balance under a range of circumstances, including power plant outages, uncertain variations in load and fluctuations in power generations (such as wind) [29]. As wind speed varies on all time scales (e.g. from seconds to minutes and from months to years), the integration of fluctuating wind power generation induces additional system balancing requirements onthe operational timescale [29].A number of studies have examined the approaches to stabilize the electricity output from wind power plants. For example, Belanger and Gagnon [30] conducted a study on the compensation of wind power fluctuations by using hydropower in Canada. Nema et al. [31] discussed the application of wind combined solar PV power generation systems and concluded that the hybrid energy system was a viable alternative to current power supply systems in remote areas. In China, He et al. [2]investigated the choices of combined power generation systems. The combinations of wind-hydro, wind-diesel, wind-solar and wind-gas power were evaluated respectively. They found that, for instance, the wind-diesel hybrid systems were used at remote areas and isolated islands. This is because the wind-diesel hybrid systems have lower generation efficiency and higher generation costs compared to other generation systems. Currently, the wind-solar hybrid systems are not economically viable for large-scale application; thus, these systems have either been used at remote areas with limited electricity demand (e.g. Gansu Subei and Qinghai Tiansuo) or for lighting in some coastal cities [2]. Liu et al. [32] adopted the EnergyPLAN model to investigate the maximum wind power penetration level in the Chinese power system. The authors derived a conclusion that approximately 26% of national power demand could be supplied by wind power by the end of 2007. However, theauthors fail to explain the provision of power reserves at different time scales due to wind power integration.Because of the smoothing effects of dispersing wind turbines at different locations (as exemplified by Drake and Hubacek [33] for the U.K., Roques [34] for the E.U. and Kempton et al. [35] for the U.S.), the integration of wind power has a very small impact on the primary reserves which are available from seconds to minutes [36]. However, the increased reserve requirements are considerable on secondary reserves (available within 10–15 min) which mainly consist of hydropower plants and gas turbine power plants [29]. Besides, the long-term reserves, which are used to restore secondary reserves after a major power deficit, will be in operation to keep power production and consumption in balance for a longer timescale (from several minutes to several hours). In the following subsection, we examine the availability of power plants providing secondary and long-term reserves and investigate the viability of energy storage system in China.中文中国的风力发电–梦想还是现实？胡巴切克摘要经过近几年风力发电能力的巨大增长，中国现在拥有44.7吉瓦的风力发电。
风力发电调查英文文献
Smart Grid and Renewable Energy, 2010, 1, 119-131doi:10.4236/sgre.2010.13017 Published Online November 2010 (/journal/sgre)119 Wind Energy Conversion System from Electrical Perspective—A SurveyHyong Sik Kim, Dylan Dah-Chuan LuSchool of Electrical and Information Engineering, University of Sydney,Sydney, AustraliaEmail: hkim4210@.auReceived October 20th, 2010; revised November 14th, 2010; accepted November 20th, 2010ABSTRACTThis paper focuses on the wind energy conversion system (WECS) with the three main electrical aspects:1) wind tur-bine generators (WTGs),2) power electronics converters (PECs) and 3) grid-connection issues. The current state of wind turbine generators are discussed and compared in some criteria along with the trends in the current WECS mar-ket, which are ‘Variable Speed’,‘Multi-MW’ and ‘Offshore’. In addition, the other crucial component in the WECS, PECs will be discussed with its topologies available in the current WECS market along with their modulation strategies. Moreover, three main issues of the WECS associating with the grid-connection, fault-ride through (FRT) capability, harmonics/interharmonics emission and flicker, which are the power quality issues, will be discussed due to the in-creasing responsibility of WECS as utility power station. Some key findings from the review such as the attractiveness of BDFRG are presented in the conclusion of this paper.Keywords: Wind Energy, Wind Turbine Generators, Power Electronic Converters, Grid-Connection, Brushless, Reluctance, Pulse-Width Modulation, Fault Ride Through Capability, Voltage Dip, Harmonics, Flicker,Power Quality, BDFRG1. IntroductionGreen house gas reduction has been one of the crucial and inevitable global challenges, especially for the last two decades as more evidences on global warming have been reported. This has drawn increasing attention to renewable energies including wind energy, which is re-garded as a relatively mature technology [1]. It recorded 159 GW for the total wind energy capacities in 2009, which is the highest capacity among the existing renew-able energy sources with excluding large-scale hydro power generators as shown in Figure 1 [2].Also, its annual installation growth rate marked 31.7% in 2009 with its growth rate having been increasing for the last few years, which indicates that wind energy is one of the fastest growing and attractive renewable en-ergy sources [3]. The increasing price-competitiveness of wind energy against other conventional fossil fuel energy sources such as coal and natural gas is another positive indication on wind energy [4]. Therefore, a vast amount of researches on WECS have been and is being under-taken intensively.WECS consists of three major aspects; aerodynamic, mechanical and electrical as shown in Figure 2.The electrical aspect of WECS can further be divided into three main components, which are wind turbine generators (WTGs), power electronic converters (PECs) and the utility grid.There are many review papers on those electrical as-pects available; however, there seem small amount of investigation and discussion on some newer concepts ofFigure 1. World renewable energy capacities in 2009 (based on [2]).Wind Energy Conversion System from Electrical Perspective—A Survey 120Figure 2. Wind energy conversion system (based on [5,6]).WGTs as well as PECs along with its modulation strate-gies. The purpose of this paper is, therefore, to reviewthese three important electrical aspects of WECS withsome of the newer concepts for WTGs, PECs with theirmodulation strategies, and some of the grid connectionissues that have risen as the penetration of wind energyon the utility grid has been increasing rapidly in the lastfew years [4].The structure of this paper is as follows: wind turbinegenerators are firstly discussed in Section 2, followed byPECs and their modulation strategies in Section 3. Then,grid-connection issues of WECS will be addressed inSection 4. In Section 5, the discussion on these three com-ponents is presented and followed by the conclusion inSection 6.2. Wind Turbine Generators2.1. Wind Turbine Generators in the CurrentMarketWTGs can be classified into three types according to itsoperation speed and the size of the associated convertersas below:∙FSWT (Fixed Speed Wind Turbine)∙VSWT (Variable Speed Wind Turbine) with:o PSFC (partial scale frequency converter)o FSFC (full scale frequency converter)FSWT including SCIG (Squirrel-Cage Induction Gen-erator), led the market until 2003 when DFIG (DoublyFed Induction Generator), which is the main concept ofVSWT with PSFC, overtook and has been the leadingWTG concept with 85% of the market share reported in2008 [4]. For VSWT with FSFC, WRSG (Wound RotorSynchronous Generator) has been the main concept;however PMSG (Permanent Magnet Synchronous Gen-erator) has been drawing more attention and increasingits market share in the past recent years due to the bene-fits of PMSG and drawbacks of WRSG [7].Since there is much literature available on these WTGconcepts in the market such as [6-13], the following sec-tion will only address the two newer concepts of WTGs,which are BDFIG (Brushless Doubly Fed InductionGenerator) and BDFRG (Brushless Doubly Fed Reluc-tance Generator), followed by the discussion with thecomparison of them to the existing concepts.2.2. Two Newer WTG Concepts2.2.1. BDFIGBDFIG is one of the most popular VSWT with PSFCtypes in the current research area due to its inheritedcharacteristics of DFIG, which is the most popular WTGtype at the current market, along with its brushless aspectthat DFIG do not possess. As shown in Figure 3, BDFIGconsists of two cascaded induction machines; one is forthe generation and the other is for the control in order toeliminate the use of sliprings and brushes, which are themain drawback of DFIG.This brushless aspect increases its reliability, which isespecially desirable in offshore application [14,15]. Otheradvantages are reported in [6,16,17] including its capa-bility with low operation speed. On the other hand,BDFIG has relatively complex aspects in its design, as-sembly and control, which are some of the main disad-vantages of BDFIG [8].2.2.2. BDFRGThere is also another brushless and two-cascaded-statorconcept of VSWT with PSFC type in the research area,which is BDFRG. As shown in Figure 4, one distinctdesign compared with BDFIG is its reluctance rotor,which is usually an iron rotor without copper windings,which has lower cost than wound rotor or PM (perma-nent magnet) rotor.This design offers some advantages on top of the ad-vantages of BDFIG including higher efficiency, easierconstruction and control including power factor controlcapability as well as the cost reduction and higher reli-ability including its “fail-safe” operating mode due to itsreluctance rotor [18-21]. Due to its very high reliability,reluctance generators have also been of interest in air-craft industry where design challenges such as harsh en-vironment operation and stringent reliability exist [22,23]. On the other hand, some of the drawbacks for BDFRGexist such as complexity of rotor deign, its larger ma-chine size due to a lower torque-volume ratio and soforth [20,24,25].Wind Energy Conversion System from Electrical Perspective—A Survey121 Figure 3. The conceptual diagram of BDFIG.Figure 4. The conceptual diagram of BDFRG.2.3. Comparison of WTG ConceptsThe advantages and disadvantages of the six concepts,the four existing in the current market and the two newerconcepts discussed in the previous section are summa-rised in Table 1 [6-21,24,25].Based on the information in Table 1, Table 2 repre-sents a comparison of those six concepts with respect tothe five criteria; energy yield, cost, reliability, grid sup-port ability and technical maturity. For energy yield,PMSG has the highest rating followed by the otherVSWT concepts and SCIG has the lowest energy yieldwith 10-15% lower value than PMSG [26] due to its fixspeed aspect. However, SCIG has the lowest cost fol-lowed by BDFRG, and WRSG has the highest cost dueto its large size wound machine. It is interesting when‘energy yield per cost’ is considered based on the esti-mated levels on energy yield and cost in Table 2. Thehighest value is achieved by neither PMSG nor SCIG;BDFRG achieves the highest estimated levels on ‘energyyield per cost’, which is supported in [19]. Reliability isclosely related to the existence of brushes and sliprings,which is the main drawback of DFIG. The reason BDFIGis rated as ‘Medium-High’ despite of its brushless aspectis because it is new and has design complexity, whichbrings down reliability as the case of the newer GermanWTGs compared with older Danish WTGs reported in[12]. On the other hand, BDFRG is rated as ‘High’ de-spite of that it is as new concept as BDFIG. It is becauseof the ‘fail-safe’ characteristic of BDFRG, which enablesits robust operation in spite of the failure on its inverteror secondary stator. Grid support ability is affected main-ly by the size of the converter and the stator connection.VSWT with FSFC has high support ability due to its fullscale frequency converter. In the case of DFIG, withPSFC, it can only provide limited support to the grid dueto its directly connected stator that absorbs the effect ofgrid fault without any mitigation. It is reported thatBDFIG and BDFRG have improved characteristics undergrid fault [16] and for grid support ability [19] respec-tively. Lastly, the maturity of the technology is straight-forward as shown in Table 2 because SCIG, DFIG andWRSG have been developed for more than a couple ofdecades followed by PMSG. As mentioned before, BDFIGand BDFRG are newer concept and therefore more re-searches are needed in order to increase its technical ma-turity and hence to be applicable in the industry.2.4. Discussion on WTGsAs observed previously, there has been ‘variable speed’trend in the WT market due to its greater energy yieldalong with other advantages and will be so in the futurewith DFIG and PMSG leading the market base on thevarious data and literature [4,8,9,27]. The two newerconcepts, BDFIG and BDFRG are also in line with thistrend.Another distinct trend is offshore wind energy. It isreported that offshore wind resource has higher quality interms of its availability and constancy, and higher spatialavailability than onshore wind resource, which makesoffshore wind very attractive [28]. However, there existgreat technical challenges on its construction and main-tenance, because of its geological accessibility that greatlydepends on the weather condition, which is an unpre-dictable external factor. Due to this reason, offshore windhas only 1.2% of the world’s total installed wind energyshare (onshore and offshore) at the current market [3]and is reported to cost 1.5-2 times more than equal-sizeonshore wind application [29]. As discussed previously,DFIG is less attractive for offshore application due to itspre-planned maintenance for brush and sliprings whereasPMSG, BDFIG and BDFRG are more attractive due toits brushless aspect. BDFRG is especially attractive forits reliability due to its reluctance rotor as discussed pre-viously. Although offshore wind has low level of instal-lation at the present, the growth rate was reported to be30% in 2009 and is expected to continue to grow [3,28].Lastly, ‘Multi-MW’ trend is also observed at the cur-rent wind turbine market [4,9,27] due to the fact that lar-ger power station has lower cost per kWh. The size of theturbine in the current market has gone up to 5-6 MW oreven greater [27], supported by the increased technicallevel in design and construction. In terms of the cost ofthe material, DFIG and BDFRG are preferable overPMSG and BDFIG for this trend since PM material inPMSG is costly, and BDFIG has a wound rotor with theWind Energy Conversion System from Electrical Perspective—A Survey122Table 1. The advantages and disadvantages of the six WTG concepts.Generator Concept (Type) Advantages DisadvantagesSCIG (FSWT) ∙Easier to design, construct and control∙Robust operation∙Low cost∙Low energy yield∙No active/reactive power controllability∙High mechanical stress∙High losses on gearPMSG (VSWT-FSPC) ∙Highest energy yield∙Higher active/reactive power controllability∙Absence of brush/slipring∙Low mechanical stress∙No copper loss on rotor∙High cost of PM material∙Demagnetisation of PM∙Complex construction process∙Higher cost on PEC∙Higher losses on PEC∙Large sizeWRSG (VSWT-FSPC) ∙High energy yield∙Higher active/reactive power controllability∙Absence of brush/slipring∙Low mechanical stress∙Higher cost of copper winding∙Higher cost on PEC∙Higher losses on PEC∙Large sizeDFIG (VSWT-PSPC) ∙High energy yield∙High active/reactive power controllability∙Lower cost on PEC∙Lower losses by PEC∙Less mechanical stress∙Compact size∙Existence of brush/slipring∙High losses on gearBDFIG (VSWT-PSPC) ∙Higher energy yield∙High active/reactive power controllability∙Lower cost on PEC∙Lower losses by PEC∙Absence of brush/slipring∙Less mechanical stress∙Compact size∙Early technical stage∙Complex controllability, design and assembly∙High losses on gearBDFRG (VSWT-PSPC) ∙Higher energy yield∙High active/reactive power controllability∙Lower cost on PEC∙Lower losses by PEC∙Absence of brush/slipring∙No copper loss on rotor∙Less mechanical stress∙Easier construction∙Early technical stage∙Complex controllability and rotor design∙High losses on gear∙Larger size than DFIGTable 2. The comparison of the six different WTG concepts.Generator Concept Energy Yield Cost Reliability Grid Support Ability Technical Maturity SCIG Low Low High Low High PMSG High Medium-High High High Medium-High WRSG Medium-High High High High High DFIG Medium-High Medium Medium Medium High BDFIG Medium-High Medium Medium-High Medium-High Low BDFRG Medium-High Low-Medium High Medium-High LowWind Energy Conversion System from Electrical Perspective—A Survey 123two wound cascaded stator, which has greater amount of windings than DFIG or BDFRG.3. Power Electronic Converters3.1. Topology of Power Electronic ConvertersAs the amount of the installed VSWT increased, so has the importance of PECs in WECS since it is the interface between WTGs and the electrical grid [1,11,30]. There are three types of converters widely available in the cur-rent wind energy market: Back-to-back PWM converter, multilevel converter and matrix converter.3.1.1. Back-to-back PWM ConvertersBack-to-back PWM converter, which is also referred as ‘two-level PWM converter’, is the most conventional type among the PEC types for VSWT. As shown in Fig-ure 5, it consists of two PWM-VSIs (voltage source in-verters) and a capacitor in between. This capacitor is often referred as a ‘DC link capacitor’ or ‘decoupling capacitor’ since it provides a separate control in the in-verters on the two sides, which are ‘machine’ and ‘grid’ side. In addition, it has lower cost due to its maturity [12].However, the DC link capacitor also becomes the main drawback of the PWM converter because it decreases the overall lifetime of the system [31]. There are other dis-advantages including switching losses and emission of high frequency harmonics, which results in additional cost in EMI-filters [1,12].3.1.2. Multilevel ConvertersCompared with two-level PWM converter, multilevel (ML) converter has three or more voltage levels, which results in lower total harmonic distortion (THD) than back-to-back PWM converter does [32]. In addition, ML converter offers higher voltage and power capability, which advocates the trend of ‘Multi-MW’ wind turbine [1,33]. Another advantage is that switching losses are smaller in ML converter than two-level PWM converter by 25% [34].One of the disadvantages on ML converter is the volt-age imbalance caused by the DC link capacitors [35,36]. Another disadvantage in some ML converter designs is uneven current stress on the switches due to its circuit design characteristic. The cost associated with the highFigure 5. Basic schematics of Back-to-Back PWM converter (based on [12]). more number of switches and the complexity of control are two other drawbacks.Since the first proposed design of ML converter, the neutral-point clamped three-level converter in 1981 [36,37], there have been various designs for ML converters in-cluding the followings [33,35,36,38]:∙Neutral Point Clamped (NPC) ML converter∙Cascade Half-Bridge (CHB) ML converter∙Fly-capacitor (FLC) ML converterThe detail of each design, which is beyond the scope of this paper, can be found in the literatures [33,35,36, 38].Out of these three ML converter designs, NPC ML converter is commonly utilised in WECS, especially in multi-MW scale WECS, due to its maturity and advan-tages [36,39]. Main drawback exists, however, with 3L- NPC (3 level-NPC) design, which is the uneven loss dis-tribution among the semiconductor devices, limiting output power of the converter [40,41]. This drawback has been overcome with the replacement of the clamping diode with the active switching devices. This modified design of NPC is referred as ‘Active NPC’ (ANPC), which was first introduced in 2001 [41,42], as shown in Figure 6. There are many advantages of ANPC including higher power rating than normal NPC by 14% [40] and robustness against the fault condition [43].3.1.3. Matrix ConvertersMatrix converters have a distinct difference from the previous two converters in a way that it is an AC-AC converter without any DC conversion in between, which indicates the absence of passive components such as the DC link capacitor and inductor in the converter design. As shown in Figure 7, the typical design of matrix con-verters consists of 9 semi-conductors that are controlled(a) (b)Figure 6. One inverter cell of (a) NPC and (b) ANPC (based on [12,36]).Wind Energy Conversion System from Electrical Perspective—A Survey124Figure 7. Basic schematics of matrix converter (based on [12,45]).with two control rules to protect the converter; three switches in a common output leg must not be turned on at the same time and the connection of all the three out-put phases must be made to an input phase constantly [12]. There are some advantages of matrix converters. The absence of DC link capacitor results in increased efficiency and overall life time of the converter as well as the reduced size and cost compared with PWM-VSI converter [4,44]. The thermal characteristic of the matrix converter is also another advantage since it can operate at the temperature up to 300˚C, which enables to adopt new technologies such as high temperature silicon carbide devices [44]. On the other hand, some of the reported disadvantages include; the limitation on the output volt-age (86% of the input voltage), its sensitivity to the grid disturbances and rapid change of the input voltage, higher conducting losses and higher cost of the switch components than PWM-VSI converter [12,32]. Further technical details of matrix converter can be found in [44]. 3.1.4. Discussion on PECIn this section, the PECs will be discussed with the crite-ria such as their power loss, loss distribution, efficiency, harmonic performance and cost.In terms of power losses, it is widely reported that ML VSCs have less power losses than 2L VSIs with 3-Level Neutral Point Clamped VSIs (3L-NPC) having even lower amount of losses over 3-Level Flying Capacitor VSIs (3L-FLC) [46-48]. This advantage of 3L-NPC, however, inherits poor power loss distribution, which is the main drawback of 3L-NPC as mentioned previously. Loss distribution is an important aspect in PEC since uneven loss distribution means uneven stress distribution among the semiconductor devices and this results the most stressed switching device to limit the total output power and switching frequency [49]. In [46,47], uneven loss distribution of 3L-NPC is reported along with other topologies such as 2L-VSI and 3L-FLC, which have even distribution. As mentioned previously, ANPC is the to-pology to reduce the unevenness among the switching devices and it is reported that 3L-ANPC possess an ad-vantage of 3L-FLC on its natural doubling of switching frequency, without flying-capacitors [50].Harmonic performance is another crucial criterion of PEC, especially for WECS as the impact of WECS on power quality of the power grid is increasing due to its increasing penetration level. The comparison on har-monic performance is commonly measured by total har-monic distortion (THD) or weighted THD (WTHD). A comparison on THD of 2L-VSI, 3L-NPC and matrix converter with PMSG is undertaken in [51] and 3L-NPC provides the lowest value of THD among the three to-pologies. This result verifies that THD decreases with increasing number of levels [46].Different PEC topologies consist of components with variable numbers and sizes that result variation in cost. Although 2L-VSI has less number of components com-pare to ML VSIs, it is estimated to be more costly due to its large LC filter, which is the result of compromise for high efficiency and low THD that ML can achieve with smaller LC filter [47,48]. Matrix converters would lie in between 2L VSIs and 3L VSIs since it has smaller num-ber of semiconductors and LC filters are required to minimise the switching frequency harmonics [52]. The cost estimation would be similar for both 3L-NPC and 3L-FLC since the excessive cost for the larger LC filter and semiconductors would be compensated with the cost for flying capacitors by considering the cost estimation in [47] with the constant switching frequency. In [53], comparison between 3L-ANPC and 3L-NPC is conducted with different IGBT ratings available in the market. In the literature, it is found that 3L-NPC is most economical (i.e. lest cost per MVA) with 2.3 kV IGBT modules at any switching frequency between 300 Hz to 1050 Hz. However, 3L-ANPC becomes more cost-effective with 3.3 kV and 4.16 kV at switching frequency over 750 Hz. In summary, it is evident that 3L-ANPC is a very at-tractive PEC topology for WECS, which is increasing its power rating, operates with high switching frequency (typically 2~5 kHz [47,51,54-57]) and requires low har-monic emission.3.2. Modulation MethodsAlong with the converter topologies, there are some modulation strategies available to produce a desired level of output voltage and current in lower frequency. Pulse- width modulation (PWM) is one of the most widely used modulation strategies for PEC with AC output, hence, this section will focus on PWM schemes for ML con-verters.While the primary goal of PWM is to produce a tar-geted low-frequency output voltage or current, it is also essential for PWM schemes to minimise the impact on the quality of the output signals such as harmonic distor-tion.Wind Energy Conversion System from Electrical Perspective—A Survey 125Among the vast amount of proposed PWM schemes, majority of them can be categorised into the following three types despite of different converter topologies [33, 36,53]:∙Carrier-Based PWM∙Space Vector Modulation (SVM)∙Selective Harmonic Elimination (SHE)These three PWM strategies will be explained in detail on the next section.3.2.1. Carrier-Based PWMCarrier-based PWM strategy has been widely utilised as the basic logic of generating the switching states is sim-ple. The basic principle is to compare a low frequency sinusoidal reference voltages to high frequency carrier signals, then produce the switching states every time the reference signal intersects carrier signals. The number of carrier signals is defined as (N-1), where N is the number of the level of multi-level VSI (eg. N = 3 for 3-Level NPC VSI) [58].The basic control diagram and modulation signals of 3-Level VSI are represented in Figure 8.From the conventional schemes, there are some modi-fied techniques proposed with multi-level or multi-phase methods in order to reduce distortion in ML inverters [59]. Basic concepts of those are shown in Figure 9.3.2.2. Space Vector Modulation (SVM)Space vector modulation (SVM) is the PWM method based on the space vector concept with d-q transforma-tion that is widely utilised in AC machines. With the de-velopment of microprocessors, it has become one of the most widely used PWM strategies for three-phase con-verters due to some of its advantages including high voltage availability, low harmonics, simple digital im-plementation and wide linear modulation range, which is one of the main aims of PWM [4,47,60].There are N3 switching states in N-level PWM inverter so in the case of 3-Level NPC VSI, there are 27 (= 33) possible switching states. As shown in Figure 10, these switching states define reference vectors, which are rep-resented by the 19 nodes in the diagram with the four classification of ‘zero’ (V0), ‘small’ (V Si), ‘medium’ (V Mi) and ‘large’ (V Li), where i = 1,2,…,6 [61]. The difference between the numbers of the switching states and space vectors indicate that there is redundancy of switching states existing for some space vectors. As indicated in Figure 10, one ‘zero’ space vector (i.e.V0) can be generated by three different switching states and six ‘small’ space vector (i.e.V Si) by two different switching states each. These redundancies provide some benefits including balancing the capacitor voltages in 3L-NPC VSI [36]. The basic principle of SVM is to select three nearest(a)(b)Figure 8. (a) Control diagram, (b) Modulation signal (sources from [36]).vectors that consist of a triangle in the space vector dia-gram that the tip of a desired reference vector is located, and generate PWM according to the switching states of those selected vectors. There are many researches on SVM to improve on various aspects such as the im-provement in neutral point (NP) balancing at higher modulation indexes [62] and the reduction of the size of DC-link in control loop for renewable application such as WECS [63].3.2.3. Selective Harmonic EliminationThe basic principle is to calculate N number of switching angles that are less than π/2 for a N-Level inverter through N number of the nonlinear equation with Fourier expansion of output voltage [64]. One equation is used toWind Energy Conversion System from Electrical Perspective—A Survey126(a)(b)Figure 9. (a) Multi-level PWM, (b) Multi-phase PWM (sources from [33]).Figure 10. Normalised space vector diagram for the three- level NPC converter (based on [61]).control the fundamental frequency through the modula-tion index and the other N-1 equations are used for elimination of the low-order harmonics components [59]. In the case of 3-Level VSI, 5th and 7th harmonic compo-nents are the two lowest-order harmonics to be elimi-nated since 3rd harmonic component is cancelled by the nature of three-phase [53]. Figure 11 depicts an example of the 3-Level SHE with 3 switching angles, a 1, a 2 & a 3 [36].It is well-known that SHE strategy provides good harmonic performance in spite of the low switching fre-quency due to its harmonic elimination nature [53,65]. Another advantage is the reduction on its switching loss due to the low switching frequency [36]. However, there are some disadvantages exist including its heavy compu-tational cost and narrow modulation range [59,65]. There are many researches on SHE such as NP balancing for 3L-NPC [36] and the increase of the number of elimi-nating low-order harmonics with simple in formulation [66].3.2.4. Discussion on Modulation MethodAmong the three modulation methods discussed above, CB-PWM [67-70] and SVM [32,56,71-74] are widely utilised in WECS. However, SHE strategy has not been utilised in WECS to the best knowledge of the author despite of its active researches with resent PEC tech-nologies such as 5-Level ANPC VSI [75]. The authors in [53] suggest the combination of using 2L SVM and SHE schemes for the switching frequency f sw ≤ 500 Hz whereas the combination of 2L SVM and 3L SVM for f sw > 500 Hz due to their performances with respect to the modulation index and switching frequency. This could be one reason for SHE schemes not to be utilised in WECS where high switching frequency is used.However, if the reason of high switching frequency in WECS is for the quality of output power, lower switch-ing frequency can be adapted with SHE strategy in WECS for high quality of output power. This would in-crease the efficiency of WECS due to less switching losses and also this will reduce a cost of filter circuits since the size of the filter would be smaller with the na-ture of harmonic elimination of SHE.Figure 11. 3-level SHE (Source from [36]).。
风力发电电力系统中英文对照外文翻译文献
中英文对照外文翻译(文档含英文原文和中文翻译)附件1：翻译译文风力发电对电力系统的影响摘要风力发电依赖于气象条件，并逐渐以大型风电场的形式并入电网，给电网带来各种影响。
电网并未专门设计用来接入风电，因此如果要保持现有的电力供应标准，不可避免地需要进行一些相应的调整。
讨论了在风电场并网时遇到的各种问题。
由于风力发电具有大容量、动态和随机的特性，它给电力系统的有功/无功潮流、电压、系统稳定性、电能质量、短路容量、频率和保护等方面带来影响。
针对这些问题提出了相应的解决建议和措施，以及更好利用风力发电。
关键词：风力发电；电力系统；影响；风电场1.引言人们普遍接受，可再生能源发电是未来电力的供应。
由于电力需求快速增长，对以化石燃料为基础的发电是不可持续的。
正相反，风力发电作为一种有前途的可再生能源受到了很多关注。
当由于工业的发展和在世界大部分地区的经济增长而发电的消费需求一直稳步增长时，它有减少排放和降低不可替代的燃料储备消耗的潜力。
当大型风电场（几百兆瓦）是一个主流时，风力发电越来越更受欢迎。
2006年间，世界风能装机容量从2005年的59091兆瓦达到74223兆瓦。
在2006年极大的生长表明，决策者开始重视的风能发展能够带来的好处。
由于到2020年12%的供电来于1250GW的安装风电装机，将节约累积10771000000吨二氧化碳[1]。
大型风电场的电力系统具有很高的容量，动态随机性能，这将会挑战系统的安全性和可靠性。
而提供电力系统清洁能源的同时，风农场也会带来一些对电力系统不利的因素。
风力发电的扩展和风电在电力系统的比重增加，影响将很可能成为风力集成的技术性壁垒。
因此，应该探讨其影响和提出克服这些问题的对策。
2.风力发电发展现状从全球风能委员会（GWEC）的报告中，拥有最高装机容量总数的国家是德国（20621兆瓦），西班牙（11615兆瓦），美国（11603兆瓦），印度（6270兆瓦）和丹麦（3136兆瓦）。
有关风能发电的英语作文
有关风能发电的英语作文英文回答：Wind energy is a rapidly growing source of renewable energy that has the potential to provide a significant portion of the world's electricity needs. It is a clean, sustainable, and cost-effective way to generate electricity, and it can help to reduce our dependence on fossil fuels.Wind turbines convert the kinetic energy of the windinto electrical energy. The turbines are mounted on towers, and the blades rotate when the wind blows. The rotation of the blades turns a generator, which produces electricity.Wind energy is a variable resource, which means that it is not always available. However, the wind can be predicted with reasonable accuracy, and wind turbines can be sited in areas where the wind blows frequently.Wind energy is a relatively new technology, but it israpidly becoming more efficient and cost-effective. The cost of wind energy has fallen significantly in recent years, and it is now competitive with other forms of renewable energy, such as solar energy.Wind energy has a number of advantages over other forms of renewable energy. It is a clean source of energy, and it does not produce any greenhouse gases. Wind turbines are also relatively quiet, and they can be sited in areas where they will not have a negative impact on the environment.Wind energy is a promising source of renewable energy that has the potential to make a significant contribution to the world's energy needs. It is a clean, sustainable, and cost-effective way to generate electricity, and it can help to reduce our dependence on fossil fuels.中文回答：风能是一种增长迅速的可再生能源，它有可能为世界提供大量的电力需求。
有关风力发电的外文文献翻译
大型风力发电对电力系统稳定性的影响Ch. Eping, J. Stenzel电力系统研究所TU DarmstadtLandgraf-Georg-Stra¼e 464283 Darmstadt/德国e-mail：*********************************.de********************************.deM. PÄoller, HMÄullerDIgSILENT GmbHHeinrich-Hertz-Stra¼e 972810 Gomaringen /德国e-mail:*******************************************摘要近年来，风力发电量不断增加，对电力系统的安全性和系统运行的影响也不断增加。
因此，最近在不同的国家已经进行一些风电影响的研究了。
这些研究的结果通常会涉及到不同的风力发电方面，如波动性，分布式风电场发电机技术，发电机控制等和后备并网预测，其他储备的要求等等。
本文重点对影响暂态稳定问题的几个方面进行分析，像发电机技术，连接点，分布式发电等对暂态稳定方面的影响分别进行了透彻分析。
1引言风力发电的重要性日益增加，特别在许多欧洲国家、美国、加拿大、和澳大利亚。
这要求风力发电对电力系统稳定性的影响进行详细分析。
因此，最近已经进行了所需的一些网络加固，资金准备要求，目前正在开展风力发电对电力系统稳定性影响的研究（如[2]）。
这些研究处理与风力发电有关的几个不同的方面，如波动性风电，当地风力资源，各种发电机技术和发电机控制。
结果大致是，不同的风力发电方面的共同并网和并网后备预测，额外的储备要求，对电力系统稳定性的影响等，但是很难的解决遇到的问题和所需的系统升级，因为要同时进行大量各种方面的研究。
本文的目的是分析和理解，而不是实际的数字和计算。
这次调查的是暂态稳定现象，特别是暂态稳定长距离输电的限制。
风力发电中英文对照外文翻译文献
中英文资料对照外文翻译水平轴风力发电机性能过渡，湍流和偏航的影响摘要最近出示的是改善的功能改善的混合动力车的的水平轴风力涡轮机（HAWT）配置Navier-Stokes势流建模方法。
研究的重点在三个问题上：湍流模型和转换模型，预测转子规定性能唤醒状态以及非轴向流（偏航）发电的影响，比较转子在国家可再生能源实验室（NREL）的测试与测量数据.简介水平轴风力涡轮机空气动力学的计算研究工作是在佐治亚理工学院进行。
本研究着重于了解影响风力涡轮机在非轴向和非均匀流入的流动机制的性能，也解决了高效的计算技术的发展，以补充现有的联合叶片元素动量理论方法。
这项工作是一个扩展的3-D的混合Navier-Stokes/potential流动求解，并已在佐治亚理工学院的水平轴风力发电机（HAWT）进行改善。
在这种方法中的三维非定常可压缩Navier-Stokes方程的解决只能在周围的转子叶片上的贴体网格这片一个很小的区域，。
远离叶片的和潜在的流动方程需要从叶片脱落的涡模拟涡细丝涡留下的Navier-Stokes地区的求解。
这些细丝自由对流的地方流动。
由于复杂的Navier-Stokes方程的计算只在附近的风力涡轮机叶片的地区，因此跟踪的涡利用拉格朗日方法，这是更有效的Navier-Stokes方程的方法级。
基本的Navier-Stokes方程混合势流的方法和其应用程序HAWT下轴流条件的记录在AIAA-99-0042（徐和Sankar，1999年）.本研究范围本文介绍了近期的流动求解的增强功能和应用程序配置的兴趣。
增强集中在以下三个方面：过渡和湍流模型，物理一致唤醒建模，建模的偏航效果。
下文简要讨论这三个领域。
过渡和湍流的建模问题：研究两种湍流模型和两个过渡模型的预测性能影响的进行评估。
一个显示Spalart-Allmaras湍流方程湍流模型（书珥等，1998），另一个对基线鲍德温 - 洛马克斯零方程湍流模型进行了研究。
风力发电技术概述作文英语
风力发电技术概述作文英语Wind power, as a renewable energy source, has garnered significant attention in recent years due to its potential to mitigate climate change and reduce dependence on fossil fuels. In this essay, we will provide an overview of wind power technology, its development, current status, and future prospects.1. Introduction to Wind Power:Wind power involves harnessing the kinetic energy of wind to generate electricity. This process typically involves wind turbines, which consist of blades mounted on a rotor connected to a generator. As the wind blows, it causes the rotor to spin, generating electricity through the generator.2. Development of Wind Power Technology:The concept of using wind energy dates back centuries,with early windmills used for tasks like grinding grain or pumping water. However, modern wind power technology began to emerge in the late 19th and early 20th centuries with the development of electricity generation. The first electricity-generating wind turbine was built in Scotland in 1887 by Professor James Blyth.3. Evolution of Wind Turbines:Over the years, wind turbine technology has advanced significantly. Early turbines were small and inefficient compared to modern designs. Today, wind turbines come in various sizes and configurations, ranging from small turbines used for residential applications to largeutility-scale turbines found in wind farms.4. Types of Wind Turbines:There are two primary types of wind turbines:horizontal-axis turbines (HAWTs) and vertical-axis turbines (VAWTs). HAWTs are the most common type and feature blades that rotate around a horizontal axis. VAWTs, on the otherhand, have blades that rotate around a vertical axis. Each type has its advantages and disadvantages, and the choice depends on factors like wind conditions and application.5. Current Status of Wind Power:Wind power has experienced rapid growth in recent decades, driven by factors such as technological advancements, government incentives, and increasing environmental awareness. According to the Global Wind Energy Council, the cumulative installed capacity of wind power reached over 700 gigawatts by the end of 2021, with significant contributions from countries like China, the United States, and Germany.6. Advantages of Wind Power:Renewable: Wind energy is renewable and abundant, making it a sustainable alternative to fossil fuels.Clean: Wind power generates electricity without emitting greenhouse gases or other pollutants, helping tomitigate climate change and improve air quality.Cost-effective: The cost of wind energy has declined significantly in recent years, making it increasingly competitive with conventional energy sources.Job creation: The wind industry creates jobs in manufacturing, installation, maintenance, and other sectors, contributing to economic growth.7. Challenges and Limitations:Despite its many advantages, wind power also faces challenges and limitations. These include:Intermittency: Wind is inherently variable, and electricity generation from wind turbines fluctuates depending on wind speeds.Land use: Wind farms require large areas of land, which can raise concerns about land use conflicts and environmental impacts.Visual and noise impacts: Wind turbines can be visually and audibly intrusive, leading to opposition from local communities.Infrastructure requirements: Wind power infrastructure, such as transmission lines, may require significant investment and planning.8. Future Prospects:Despite these challenges, the future looks promisingfor wind power. Continued advancements in technology, such as larger and more efficient turbines, improved energy storage solutions, and smarter grid management, will help overcome many of the current limitations. Additionally, supportive government policies and growing public demandfor clean energy are expected to drive further expansion of wind power worldwide.In conclusion, wind power technology has made significant strides in recent years and has emerged as akey player in the transition to a more sustainable energy future. With ongoing innovation and investment, wind power will continue to play a crucial role in reducing carbon emissions and ensuring energy security for generations to come.。
风力发电论文摘要英文翻译
风力发电论文摘要英文翻译摘要风力发电是清洁的、无污染的可再生能源，它的优势已被人们所认识。
但是现阶段风力发电成本与常规能源相比仍不具有优势，特别是在我国，风力发电成本还难与同常规能源相竞争，这制约了我国风电事业的发展。
因此全面地研究我国风力发电成本、研究影响风力发电成本的因素、找到降低风力发电成本的途径，对促进我国风电事业的发展、改进我国能源结构、治理我国的环境污染具有重要的现实意义。
为此社会总成本实际成本风电场关键字:风力发电ABSTRACTThis paper introduces wind Power generation cost in china Wind Power is a kind of cleaner and no pollution and regenerate power, Its benefits has been known by most people.But it has been yet inferior to routine power in cost, especially in our country. So studying the cost of the wind power generation and studying the factors of affecting wind power generation costs and finding the ways of decreasing the wind power generation costs in our country have very important realistic meanings and it can promote the cause of the wind power generation and improvethe energy constitutes and administer circumstance pollution in our country.hence,this paper is accomplished to develop the study of the wind power generation cost:First ,the history and the present of wind power generation are introduced: Second ,the social cost of wind power generation are studied by means of comprehensive analyses.draw a conclusion;the social cost of wind power generation is lower;Third ,the real cost of wind power generation are studied by model of wind distribution and generation amount and calculating the cost of wind power generation;the factors affecting wind power generation cost are studied by sensitivities with a real example and draw a conclusion:average wind rate is most influence to wind power generation cost and the ways of reducing wind power generation cost are discussed. Fourth ,the trend of wind power generation cost is analysised and draw a conclusion;wind power generation cost is dropping.Key word: wind power generation the social cost the real cost wind powergeneration farm目录1 概述 (1)1.1风力发电的研究现状 (1)1.2我国风力发电的发展状况 (3)1.3发展风力发电的必要性和意义 ......................................... 4 2中国风力发电社会总成本的研究 (6)2.1研究方法的选择 (6)2.2原理及步骤 (6)2.2.1具体步骤 .....................................................62.2.2 进行层次总排序 ...............................................8 3层次分析综合评价法的应用 (9)3.1建立层次结构模型 (9)3.2构造判断矩阵 (9)3.3 进行层次单排序极其一致性检验 (11)3.4进行层次总排序 (13)3.5层次总排序一致性检验 (14)3.6世界各国促进风力发电发展的激励政策 (14)3.7小结 .............................................................. 16 4中国风力发电的成本走势分析 (16)4.1风机国产化的形式对成本走势的影响 (16)4.2.国家政策 (16)4.3目前我国风力发电成本较高原因分析 (17)4.3.1目前我国风力发电成本较高原因 ................................174.3.2解决的方法 ..................................................194.3.3风力发电在我国发展的美好前景 ................................19 谢辞 ..................................................................20 参考文献 ...............................................................21大连交通大学信息工程学院2011届本科生毕业设计(论文)1 概述1.1风力发电的研究现状风力发电于1890年起源于丹麦，之后经过几个重要的发展阶段。
有关风能发电的英语作文
有关风能发电的英语作文英文回答：Wind energy is a form of renewable energy that harnesses the power of the wind to generate electricity. It is a clean and sustainable source of energy that does not produce any emissions or waste. Wind turbines, which are used to convert the kinetic energy of the wind into electrical energy, are typically installed in windy areas, such as coastal regions, mountain passes, and open fields.One of the main advantages of wind energy is its cost-effectiveness. Wind turbines have become increasingly efficient and affordable over the years, making wind energy one of the most competitive renewable energy sources. Additionally, wind energy is a reliable source of energy, as wind is a relatively predictable resource.However, wind energy also has some disadvantages. One of the main challenges is that wind power is intermittent,meaning that it is not always available when needed. This can be overcome by integrating wind energy with other renewable energy sources, such as solar energy, which is available during the day when wind power is typically less available.Another challenge with wind energy is that wind turbines can have a negative impact on wildlife,particularly birds and bats. However, there are a number of measures that can be taken to mitigate this impact, such as siting wind turbines in areas where there is less wildlife activity and using bird deterrents.Overall, wind energy is a promising renewable energy source that has the potential to make a significant contribution to meeting our global energy needs. It is a clean, sustainable, and cost-effective source of energythat can help us to reduce our reliance on fossil fuels.中文回答：风能是一种可再生能源，利用风力发电。
风力发电机用专业英语中文对照全
风力发电机用专业英语中文对照风力机 wind turbine风电场 wind power station wind farm风力发电机组 wind turbine generator system WTGS水平轴风力机 horizontal axis wind turbine垂直轴风力机 vertical axis wind turbine轮毂（风力机） hub (for wind turbine)机舱 nacelle支撑结构 support structure for wind turbine关机 shutdown for wind turbine正常关机 normal shutdown for wind turbine紧急关机 emergency shutdown for wind turbine空转 idling锁定 blocking停机 parking静止 standstill制动器 brake停机制动 parking brake风轮转速 rotor speed控制系统 control system保护系统 protection system偏航 yawing设计和安全参数 design situation设计工况 design situation载荷状况 load case外部条件 external conditions设计极限 design limits极限状态 limit state使用极限状态 serviceability limit states极限限制状态 ultimate limit state最大极限状态 ultimate limit state安全寿命 safe life严重故障 catastrophic failure潜伏故障 latent fault dormant failure风特性wind characteristic风速 wind speed风矢量 wind velocity旋转采样风矢量 rotationally sampled wind velocity 额定风速 rated wind speed切入风速 cut-in speed切出风速 cut-out speed年平均annual average年平均风速 annual average wind speed平均风速mean wind speed极端风速 extreme wind speed安全风速 survival wind speed参考风速reference wind speed风速分布 wind speed distribution瑞利分布RayLeigh distribution威布尔分布 Weibull distribution风切变 wind shear风廓线风切变律 wind profile wind shear law 风切变指数wind shear exponent对数风切变律 logarithmic wind shear law风切变幂律 power law for wind shear下风向down wind上风向 up wind阵风gust粗糙长度 roughness length湍流强度 turbulence intensity湍流尺度参数turbulence scale parameter湍流惯性负区 inertial sub-range风场 wind site测量参数 measurement parameters测量位置 measurement seat最大风速 maximum wind speed风功率密度 wind power density风能密度 wind energy density日变化 diurnal variation年变化 annual variation轮毂高度 hub height风能 wind energy标准大气状态 standard atmospheric state风切变影响 influence by the wind shear阵风影响 gust influence风速频率 frequency of wind speed环境 environment工作环境 operational environment气候 climate海洋性气候 ocean climate大陆性气候 continental climate露天气候 open-air climate室内气候 indoor climate极端 extreme日平均值 daily mean极端最高 extreme maximum年最高 annual maximum年最高日平均温度 annual extreme daily mean of temperature月平均温度 mean monthly temperature 空气湿度 air humidity绝对湿度 absolute humidity相对湿度 relative humidity降水 precipitation雨 rain冻雨 freezing rain霜淞 rime雨淞 glaze冰雹 hail露 dew雾 fog盐雾 salt fog雷暴 thunderstorm雪载 snow load标准大气压 standard air pressure平均海平面 mean sea level海拔 altitude辐射通量 radiant flux太阳辐射 solar radiation直接太阳辐射 direct solar radiation 天空辐射 sky radiation太阳常数 solar constant太阳光谱 solar spectrum黑体 black body白体 white body温室效应 greenhouse effect环境温度 ambient temperature表面温度 surface temperature互联 interconnection输出功率output power额定功率 rated power最大功率 maximum power电网连接点 network connection point电力汇集系统 power collection system风场电器设备 site electrical facilities 功率特性power performance静电功率输出 net electric power output 功率系数 power performance自由流风速 free stream wind speed扫掠面积 swept area轮毂高度 hub height测量功率曲线 measurement power curve外推功率曲线 extrapolated power curve年发电量 annual energy production可利用率 availability数据组功率特性测试 data set for power performance measurement 精度 accuracy测量误差 uncertainty in measurement分组方法 method of bins测量周期 measurement period测量扇区 measurement sector日变化 diurnal variations浆距角 pitch angle距离常数 distance constant试验场地 test site气流畸变 flow distortion障碍物 obstacles复杂地形带 complex terrain风障 wind break声压级 sound pressure level声级 weighted sound pressure level; sound level视在声功率级 apparent sound power level指向性 directivity音值 tonality声的基准面风速 acoustic reference wind speed标准风速 standardized wind speed基准高度 reference height基准粗糙长度 reference roughness length基准距离 reference distance掠射角 grazing angle风轮 wind rotor风轮直径 rotor diameter风轮扫掠面积 rotor swept area风轮仰角 tilt angle of rotor shaft风轮偏航角 yawing angle of rotor shaft风轮额定转速 rated turning speed of rotor 风轮最高转速 maximum turning speed of rotor 风轮尾流 rotor wake尾流损失 wake losses风轮实度 rotor solidity实度损失 solidity losses叶片数 number of blades叶片 blade等截面叶片 constant chord blade变截面叶片variable chord blade叶片投影面积 projected area of blade叶片长度 length of blade叶根 root of blade叶尖tip of blade叶尖速度 tip speed浆距角 pitch angle翼型 airfoil前缘 leading edge后缘tailing edge几何弦长 geometric chord of airfoil平均几何弦长 mean geometric of airfoil气动弦线 aerodynamic chord of airfoil翼型厚度 thickness of airfoil翼型相对厚度 relative thickness of airfoil厚度函数 thickness function of airfoil中弧线 mean line弯度 degree of curvature翼型族 the family of airfoil弯度函数 curvature function of airfoil叶片根梢比 ratio of tip-section chord to root-section chord 叶片展弦比 aspect ratio叶片安装角setting angle of blade叶片扭角 twist of blade叶片几何攻角 angle of attack of blade叶片损失blade losses叶尖损失tip losses颤振flutter迎风机构orientation mechanism调速机构 regulating mechanism风轮偏测式调速机构 regulating mechanism of turning wind rotor out of the wind sideward变浆距调速机构regulating mechanism by adjusting the pitch of blade 整流罩 nose cone顺浆 feathering阻尼板spoiling flap风轮空气动力特性 aerodynamic characteristics of rotor叶尖速度比 tip-speed ratio额定叶尖速度比 rated tip-speed ratio升力系数 lift coefficient阻力系数 drag coefficient推或拉力系数 thrust coefficient偏航系统滑动制动器sliding shoes偏航 yawing主动偏航active yawing被动偏航 passive yawing偏航驱动 yawing driven解缆 untwist塔架tower独立式塔架 free stand tower拉索式塔架 guyed tower塔影响效应 influence by the tower shadow 功率特性测试功率特性 power performance净电功率输出 net electric power output功率系数 power coefficient自由流风速 free stream wind speed扫掠面积swept area测量功率曲线 measured power curve外推功率曲线 extrapolated power curve年发电量 annual energy production数据组 data set可利用率 availability精度 accuracy测量误差 uncertainty in measurement分组方法 method of bins测量周期 measurement period测量扇区 measurement sector距离常数 distance constant试验场地 test site气流畸变 flow distortion复杂地形地带 complex terrain风障 wind break声压级 sound pressure level声级 weighted sound pressure level视在声功率级 apparent sound power level指向性 directivity音值 tonality声的基准风速 acoustic reference wind speed 标准风速 standardized wind speed基准高度 reference height基准粗糙长度 reference roughness基准距离 reference distance掠射角 grazing angle比恩法 method of bins标准误差 standard uncertainty风能利用系数 rotor power coefficient力矩系数 torque coefficient额定力矩系数 rated torque coefficient起动力矩系数starting torque coefficient最大力矩系数maximum torque coefficient过载度 ratio of over load风力发电机组输出特性 output characteristic of WTGS调节特性 regulating characteristics平均噪声 average noise level机组效率efficiency of WTGS使用寿命 service life度电成本 cost per kilowatt hour of the electricity generated by WTGS 发电机同步电机 synchronous generator异步电机 asynchronous generator感应电机 induction generator转差率 slip瞬态电流 transient rotor笼型 cage绕线转子 wound rotor绕组系数 winding factor换向器 commutator集电环 collector ring换向片 commutator segment励磁响应 excitation response制动系统制动系统 braking制动机构 brake mechanism正常制动系 normal braking system紧急制动系 emergency braking system空气制动系 air braking system液压制动系 hydraulic braking system电磁制动系 electromagnetic braking system 机械制动系 mechanical braking system辅助装置 auxiliary device制动器释放 braking releasing制动器闭合 brake setting液压缸 hydraulic cylinder溢流阀 relief valve泻油 drain齿轮马达 gear motor齿轮泵 gear pump电磁阀solenoid液压过滤器 hydraulic filter液压泵hydraulic pump液压系统 hydraulic system油冷却器 oil cooler压力控制器pressure control valve压力继电器pressure switch减压阀reducing valve安全阀 safety valve设定压力setting pressure切换switching旋转接头rotating union压力表pressure gauge液压油hydraulic fluid液压马达hydraulic motor油封oil seal刹车盘 brake disc闸垫 brake pad刹车油 brake fluid闸衬片 brake lining传动比 transmission ratio齿轮gear齿轮副gear pair平行轴齿轮副 gear pair with parallel axes 齿轮系 train of gears行星齿轮系 planetary gear train小齿轮 pinion大齿轮 wheel , gear主动齿轮 driving, gear从动齿轮 driven gear行星齿轮 planet gear行星架 planet carrier太阳轮 sun gear内齿圈 ring gear外齿轮external gear内齿轮internal内齿轮副 internal gear pair增速齿轮副 speed increasing gear增速齿轮系 speed increasing gear train中心距 center distance增速比 speed increasing ratio齿面 tooth flank工作齿面 working flank非工作齿面non-working flank模数 module齿数 number of teeth啮合干涉 meshing interference齿廓修行 profile modification , profile correction 啮合 engagement, mesh齿轮的变位 addendum modification on gears变位齿轮 gears with addendum modification圆柱齿轮 cylindrical gear直齿圆柱齿轮 spur gear斜齿圆柱齿轮 helical gear single-helical gear 节点 pitch point节圆pitch circle齿顶圆 tip circle齿根圆 root circle直径和半径 diameter and radius齿宽 face width齿厚 tooth thickness压力角 pressure angle圆周侧隙 circumferential backlash蜗杆 worm蜗轮 worm wheel联轴器 coupling刚性联轴器 rigid coupling万向联轴器 universal coupling安全联轴器 security coupling齿 tooth齿槽 tooth space斜齿轮 helical gear人字齿轮 double-helical gear齿距 pitch法向齿距 normal pitch轴向齿距 axial pitch齿高 tooth depth输入角 input shaft输出角 output shaft柱销pin柱销套roller行星齿轮传动机构planetary gear drive mechanism 中心轮 center gear单级行星齿轮系 single planetary gear train柔性齿轮 flexible gear刚性齿轮 rigidity gear柔性滚动轴承 flexible rolling bearing输出联接 output coupling刚度 rigidity扭转刚度 torsional rigidity弯曲刚度 flexural rigidity扭转刚度系数 coefficient of torsional起动力矩 starting torque传动误差 transmission error传动精度 transmission accuracy固有频率 natural frequency弹性联接 elastic coupling刚性联接 rigid coupling滑块联接 Oldham coupling固定联接 integrated coupling齿啮式联接 dynamic coupling花键式联接 splined coupling牙嵌式联接 castellated coupling 径向销联接 radial pin coupling周期振动 periodic vibration随机振动 random vibration峰值 peak value临界阻尼 critical damping阻尼系数 damping coefficient阻尼比 damping ratio减震器 vibration isolator振动频率 vibration frequency幅值 amplitude位移幅值displacement amplitude速度幅值 velocity amplitude加速度幅值 acceleration amplitude控制与监控系统远程监视 telemonitoring协议 protocol实时 real time单向传输 simplex transmission半双工传输 half-duplex transmission双工传输 duplex transmission前置机 front end processor运输终端 remote terminal unit调制解调器 modulator-demodulator数据终端设备 data terminal equipment接口 interface数据电路 data circuit信息 information状态信息 state information分接头位置信息 tap position information监视信息 monitored information设备故障信息 equipment failure information 告警 alarm返回信息 return information设定值 set point value累积值 integrated total integrated value瞬时测值 instantaneous measured计量值 counted measured metered measured metered reading 确认 acknowledgement信号 signal模拟信号 analog signal命令 command字节 byte位bit地址 address波特 baud编码 encode译码 decode代码 code集中控制 centralized control可编程序控制 programmable control微机程控 minicomputer program模拟控制 analogue control数字控制 digital control强电控制 strong current control弱电控制 weak current control单元控制 unit control就地控制 local control联锁装置 interlocker模拟盘 analogue board配电盘 switch board控制台 control desk紧急停车按钮 emergency stop push-button 限位开关 limit switch限速开关 limit speed switch有载指示器on-load indicator屏幕显示 screen display指示灯 display lamp起动信号 starting signal公共供电点 point of common coupling闪变 flicker数据库data base硬件 hardware硬件平台 hardware platform层 layer level class模型 model响应时间 response time软件 software软件平台 software platform系统软件 system software自由脱扣 trip-free基准误差 basic error一对一控制方式 one-to-one control mode 一次电流 primary current一次电压 primary voltage二次电流 secondary current二次电压 secondary voltage低压电器 low voltage apparatus额定工作电压 rated operational voltage 额定工作电流 rated operational current 运行管理 operation management安全方案 safety concept外部条件 external conditions失效 failure故障 fault控制柜 control cabinet冗余技术 redundancy正常关机 normal shutdown失效-安全 fail-safe排除故障 clearance空转 idling外部动力源 external power supply锁定装置 locking device运行转速范围 operating rotational speed range临界转速 activation rotational speed最大转速 maximum rotational speed过载功率 over power临界功率activation power最大功率 maximum power短时切出风速 short-term cut-out wind speed外联机试验 field test with turbine试验台 test-bed台架试验 test on bed防雷系统 lighting protection system外部防雷系统 external lighting protection system 内部防雷系统 internal lighting protection system 等电位连接 equipotential bonding接闪器 air-termination system引下线 down-conductor接地装置 earth-termination system接地线 earth conductor接地体 earth electrode环形接地体 ring earth external基础接地体 foundation earth electrode等电位连接带 bonding bar等电位连接导体 bonding conductor保护等级 protection lever防雷区 lighting protection zone雷电流 lighting current电涌保护器 surge suppressor共用接地系统 common earthing system接地基准点 earthing reference points持续运行 continuous operation持续运行的闪变系数 flicker coefficient for continuous operation 闪变阶跃系数 flicker step factor最大允许功率 maximum permitted最大测量功率 maximum measured power电网阻抗相角 network impedance phase angle正常运行 normal operation功率采集系统 power collection system额定现在功率 rated apparent power额定电流 rated current额定无功功率 rated reactive power停机 standstill起动 start-up切换运行 switching operation扰动强度 turbulence intensity电压变化系数 voltage change factor风力机端口 wind turbine terminals风力机最大功率 maximum power of wind turbine 风力机停机 parked wind turbine安全系统 safety system控制装置 control device额定载荷 rated load周期 period相位 phase频率 frequency谐波 harmonics瞬时值 instantaneous value同步 synchronism振荡oscillation共振 resonance波 wave辐射radiation衰减 attenuation阻尼 damping畸变 distortion电electricity电的 electric静电学 electrostatics电荷 electric charge电压降 voltage drop电流 electric current导电性 conductivity电压 voltage电磁感应 electromagnetic induction 励磁 excitation电阻率 resistivity导体 conductor半导体 semiconductor电路 electric circuit串联电路 series circuit电容 capacitance电感 inductance电阻 resistance电抗 reactance阻抗 impedance传递比 transfer ratio交流电压 alternating voltage交流电流 alternating current脉动电压 pulsating voltage脉动电流 pulsating current直流电压 direct voltage直流电流 direct current瞬时功率 instantaneous power有功功率 active power无功功率 reactive power有功电流 active current无功电流 reactive current功率因数 power factor中性点 neutral point相序 sequential order of the phase电气元件 electrical device接线端子 terminal电极 electrode地 earth接地电路 earthed circuit接地电阻 resistance of an earthed conductor 绝缘子 insulator绝缘套管 insulating bushing母线 busbar线圈 coil螺纹管 solenoid绕组 winding电阻器 resistor电感器 inductor电容器 capacitor继电器 relay电能转换器 electric energy transducer 电机 electric machine发电机 generator电动机 motor变压器 transformer变流器 converter变频器 frequency converter整流器 rectifier逆变器 inverter传感器 sensor耦合器 electric coupling放大器 amplifier振荡器oscillator滤波器 filter半导体器件 semiconductor光电器件 photoelectric device触头 contact开关设备 switchgear控制设备 control gear闭合电路 closed circuit断开电路 open circuit通断 switching联结 connection串联 series connection并联 parallel connection星形联结 star connection三角形联结 delta connection 主电路 main circuit辅助电路 auxiliary circuit 控制电路 control circuit信号电路 signal circuit保护电路 protective circuit 换接 change-over circuit换向 commutation输入功率 input power输入 input输出 output负载load加载 to load充电 to charge放电 to discharge有载运行 on-load operation空载运行 no-load operation开路运行 open-circuit operation 短路运行 short-circuit operation 满载 full load效率 efficiency损耗 loss过电压 over-voltage过电流 over-current欠电压 under-voltage特性 characteristic绝缘物 insulant隔离 to isolate绝缘 insulation绝缘电阻 insulation resistance品质因数 quality factor泄漏电流 leakage current闪烙 flashover短路 short circuit噪声 noise极限值 limiting value额定值 rated value额定 rating环境条件 environment condition 使用条件 service condition工况 operating condition额定工况 rated condition负载比 duty ratio绝缘比 insulation ratio介质试验 dielectric test常规试验 routine test抽样试验 sampling test验收试验 acceptance test投运试验 commissioning test维护试验 maintenance test加速 accelerating特性曲线 characteristic额定电压rated voltage额定电流 rated current额定频率rated frequency温升 temperature rise温度系数 temperature coefficient端电压 terminal voltage短路电流 short circuit current可靠性 reliability有效性 availability耐久性 durability维修 maintenance维护 preventive maintenance工作时间 operating time待命时间 standby time修复时间 repair time寿命 life使用寿命 useful life平均寿命 mean life耐久性试验 endurance test寿命试验 life test可靠性测定试验 reliability determination test 现场可靠性试验 field reliability test加速试验 accelerated test安全性 fail safe应力 stress强度 strength试验数据 test data现场数据 field data电触头 electrical contact主触头 main contact击穿 breakdown耐电压 proof voltage放电 electrical discharge透气性 air permeability电线电缆 electric wire and cable电力电缆 power cable通信电缆 telecommunication cable油浸式变压器 oil-immersed type transformer 干式变压器 dry-type transformer自耦变压器 auto-transformer有载调压变压器 transformer fitted with OLTC 空载电流 non-load current阻抗电压 impedance voltage电抗电压 reactance voltage电阻电压 resistance voltage分接 tapping配电电器 distributing apparatus控制电器 control apparatus开关 switch熔断器 fuse断路器 circuit breaker控制器 controller接触器 contactor机械寿命 mechanical endurance电气寿命 electrical endurance旋转电机 electrical rotating machine直流电机 direct current machine交流电机 alternating current machine同步电机 synchronous machine异步电机 asynchronous machine感应电机 induction machine励磁机 exciter饱和特性 saturation characteristic开路特性 open-circuit characteristic负载特性 load characteristic短路特性 short-circuit characteristic额定转矩 rated load torque规定的最初起动转矩 specifies breakaway torque交流电动机的最初起动电流 breakaway starting current if an a.c. 同步转速 synchronous speed转差率 slip短路比 short-circuit ratio同步系数 synchronous coefficient空载 no-load系统system触电；电击 electric block正常状态 normal condition接触电压 touch voltage跨步电压 step voltage对地电压 voltage to earth触电电流 shock current残余电流 residual current安全阻抗 safety impedance安全距离safety distance安全标志 safety marking安全色 safety color中性点有效接地系统 system with effectively earthed neutral 检修接地 inspection earthing工作接地 working earthing保护接地 protective earthing重复接地 iterative earth故障接地 fault earthing过电压保护 over-voltage protection过电流保护 over-current protection断相保护 open-phase protection防尘 dust-protected防溅protected against splashing防滴 protected against dropping water防浸水 protected against the effects of immersion 过电流保护装置 over-current protective device保护继电器 protective relay接地开关 earthing switch漏电断路器 residual current circuit-breaker灭弧装置 arc-control device安全隔离变压器 safety isolating transformer避雷器 surge attester ; lightning arrester保护电容器 capacitor for voltage protection安全开关 safety switch限流电路 limited current circuit振动 vibration腐蚀 corrosion点腐蚀 spot corrosion金属腐蚀 corrosion of metals化学腐蚀 chemical corrosion贮存 storage贮存条件 storage condition运输条件 transportation condition空载最大加速度 maximum bare table acceletation 电力金具悬垂线夹 suspension clamp耐张线夹 strain clamp挂环 link挂板 clevis球头挂环 ball-eye球头挂钩 ball-hookU型挂环 shackleU型挂钩U-bolt联板 yoke plate牵引板 towing plate挂钩 hook吊架 hanger调整板 adjusting plate花篮螺栓 turn buckle接续管 splicing sleeve补修管 repair sleeve调线线夹 jumper clamp防振锤 damper均压环 grading ring屏蔽环 shielding ring间隔棒 spacer重锤 counter weight线卡子 guy clip心形环 thimble设备线夹 terminal connectorT形线夹 T-connector硬母线固定金具 bus-bar support母线间隔垫bus-bar separetor母线伸缩节 bus-bar expansion外光检查 visual ins振动试验 vibration tests老化试验 ageing tests冲击动载荷试验 impulse load tests耐腐试验 corrosion resistance tests 棘轮扳手 ratchet spanner专用扳手 special purpose spanner万向套筒扳手 flexible pliers可调钳 adjustable pliers夹线器 conductor holder电缆剪 cable cutter卡线钳 conductor clamp单卡头 single clamp双卡头 double clamp安全帽 safety helmet安全带 safety belt绝缘手套 insulating glove绝缘靴 insulating boots护目镜 protection spectacles 缝焊机 seam welding machine。
毕业论文风力发电机技术参考文献外文
Wind Power Generation TechnologyWind is very important and reserves of energy, it is safe, clean, and can provide abundant energy, stability of the stream. Now, use wind power has become the main form of wind, the world's attention, and the fastest.Wind energy technology is a high-tech; it relates more than a dozen of subjects, including meteorology,aerodynamics, structural mechanics, computer technology, electronic control technology,material science,chemistry, electrical engineering, electrical engineering, so the difficulty of a system technology may beyond the difficulty of space technology. First, The division of wind energy technologies:Wind energy technology is divided into large-scale wind power technology and small and medium sized wind power technology, although both are wind energy technology, working principles are the same, the two industries are completely different: specific performance of the "policy orientation is different in different markets, different applications, applied technology is different, totally belong to the same kinds of industries in the two sectors. Therefore, in China machinery industry meeting on the wind to large wind power and wind power to distinguish between small and medium treated separately. In addition, to meet different market needs, extending from the wind and solar technology has not only promoted the development of small wind power technology, but also for the small wind power opens up new markets.1. Large-scale wind power technology:The technology of large-scale wind power in China still has a certain gap between international.The technology of large-scale wind power technology originated in Denmark and some other European countries, the wind power industry propelled by the government, because of the local wind resource-rich,large-scale wind power technology and equipment ahead of the international development. Our government has also started to boost the development of large-scale wind power technology, and a range of policies to guide industry development. Large-scale wind power technology are for the large-scale wind turbine design,wind turbine applications for large area on the very strict environmental requirements are applied to limited resources, wind energy resource-rich wind field, to accept a variety of perennial bad environment that something was the complex nature of the environment, high demands on the technology up on the line.Currently large-scale wind power technology in general is not yet ripe, the core technology of large-scale wind power still rely on foreign, national policy guidance to the domestic wind power project launched in various places, like crazy, all overlook forward to slice. Worthy of the name "mad electricity" through the wind began to Negative effect and Precaution policy. Although wind power projects have been started, but more as complementary type, complete with independent intellectual property rights of large-scale wind power systems technology and core technology few. The test environment needs to have been a large-scale wind power technology to mature. In addition, the large-scale wind power generation technology and network technology has also improved a number of issues still restrict the development of large-scale wind power technology.2. The technology of small wind power:The technology of small wind power in China could compare with the international technology.In 1970s, the small wind power technology in China had been developed which has wind resources for a better situation, including Inner Mongolia, Xinjiang areas, the first small wind power technology is widely used in power transmission project to the Township for a one of farmers and herdsmen household power supply, continuously updated as the technology improvement and development, not only alone but also with the combination of complementary optical has been widely used in distributed independent power supply. These years as Chinese exports of small and medium wind steadily. Internationally, China's small and medium sized wind power technology and wind and solar technology have leapt to international leadership.Small wind power technology is mature and relatively small by natural resource constraints, distributed independent power as a significant effect not only connected, but also the formation of more stable and reliable combination of optical complementary technologies scenery Moreover, technology is completely self-localization. Both from a technical or price in the international arena are very competitive; with international has now started a small wind power in China brand; "wall flower wall Hong" has intensified. In the country's most technical advantages and competitiveness of small and medium wind power has always been forgotten by the government and policy in a corner of reasons, in the early states has been to locate the small and medium sized wind power in Inner Mongolia, Xinjiang, farmers and herdsmen in remote areas to use and return into the agricultural class, low cost, shoddy, low-performance reliability, security, no security of land mostly sparsely populated areas, most of the domestic market are subject to loss of reliability of large price war; in people subconsciously form a poor understanding of So get national attention and development.Domestic small wind power technology in the "low wind start, low wind speed generation, pitch moment, multiple protection, and a series of technical attention by the international market and international clientsunanimously approved, has a leading position. Moreover, the small and medium Wind power technology is ultimately distributed independent power supply to meet end-market, rather than large-scale wind power generation and network technologies to meet the domestic monopoly market, technology, update rate must be adapted to a broad and rapidly growing market.3. wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar Energy Technology, combines a variety of applications of new technology, and it covers many areas, the wide range of applications, technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature, most large-scale and industrial development of the industry, separate and individual solar wind has its drawbacks of development, but both wind and solar power complementary combined to realize the two new configuration of energy in natural resources, the technical programs of integration, performance and price compared to aspects of the new energy source for the most reasonable, not only reduces the demand to meet under the same unit cost and expand the scope of application of the market, also increases the reliability of the product.In addition: solar and wind power are both new energy, solar energy than the wind started to be late more than 30 per solar PV / W by the general public about the price of recognition can be converted to a 15% rate;while the price of small wind power conversion rate is only 1/5-1/6 of the same 60% -80%, only the low price Worse still suppressed, photoelectric production of pollution on the environment greater than wind power, than substantial development in wind energy, this comparison contrast twist of meditation ......, if people use the energy from the point of view, our goal is to meet the electricity from wind power generating capacity to measure the cost of solar energy economy than many .Wind, solar and wind power integration advantages, not only for the "energy saving, emission reduction,"opened up new horizons for the application of science to meet human needs, for the world to open a fourthRevolution.Second，Wind power has three kinds of operation mode:one is independent operation mode, usually a small wind generators to one or a few families to provide power, storage battery energy, to ensure the electricity without wind, Second is the wind turbines and other power mode (such as engine power), combining to aunit or an village or an island power supply, Three is wind power into conventional power operate and to provide electric power grid, is often a wind tens or hundreds of sets installed wind generators, this is the main development direction of wind power.Wind power system in the two main parts is wind machine and generators. Wind turbines to change from adjusting technique, plasma generator toward VSCF technology, this is the development trend of wind power technology is the core technology nowadays wind turbines. The following simple introduction of this two respects.1 the change of wind plasma from regulationWind turbines impeller, will capture the wind by converting wind effects on the mechanical wheeltorque.Change is the change from adjustment with vertical axis wind leaf surface of Angle, thus affecting the force and the blade, when the wind resistance increases, the output power of the fan is kept constant power output. By regulating mode, fan from the output power curve is smooth. In the rated wind leaf Angle of attack,controller will be placed near zero, do not change, approximate distance equal to adjust for pulp. In the rated wind above, variable structure control function from pulp, adjust the blade Angle of attack, the output power control in near ratings. Change from the wind plasma starting from wind speed is set slurry machine downtime at low impact stress relative ease. The normal work, is mainly adopts power control, in practical applications, power and speed is directly proportional to the set. Small changes will cause the wind changes of wind.Due to the change of wind from pulp by adjusting the impact than other wind from small, can reduce material utilization rate, reduce overall weight. And the change of wind from accommodation type at low speed, can make the blades, keep good Angle of attack than accommodation type stall wind turbines have better energy output, therefore is suitable for low average speed of the region.Change from another advantage of regulation, when the winds reach a certain value, stall type of wind and downtime, must from type machine can gradually changes to the wind load without a blades of open mode, avoid wing, increase of wind turbine.Change is to adjust the defect is sensitive response requires gusts. Because the wind accommodation typestall fan vibration power pulse are small, and accommodation type from wind turbines is bigger, especially for the change from the constant speed windmills way, this kind of circumstance, this does not require more obvious change in the fan is the response speed of wind system to fast enough, can reduce this phenomenon.Third, the development of wind energy technology requires constant innovation:At present, China's wind energy development in technological innovation is still very weak, the lack of core technologies with independent intellectual property. Thus, much would import technology from abroad.Although the arrival of knowledge economy era, all countries take full advantage of global resources and international cooperation through the introduction of technology to bridge the gap and improve competitiveness. But if there is no capability of independent innovation, not know what the introduction of advanced technologies, are not able to absorb the future, can not carry out another record, which is on the one hand; on the other hand, the core technology is the introduction of foreign countries cannot, and must be rely on innovation to master the core technology; Moreover, the domestic policy of independent innovation of technology needs to supporting, guiding, supporting, with the core technology of wind energy products to be increasing support, such a "wall flower wall incense" situation can be change, innovation and power can come from constant innovation.In short: the wind power industry continuing to creating in a single generation from wind energy technology to power the various areas of need ,its additional products have emerged such as: street, landscape, traffic control, communication, irrigation, planting, breeding, sea water desalination , fire, alarm, islands, mountains and so on. Shows the development of wind energy in this new industry can be brought aboutnumerous development and transformation of traditional industries, but the application of wind energy technology in various fields has become the industry's benchmark. World revolution will be caused by wind energy technology from the New Energy and Industrial revolution.风力发电技术风能是非常重要并储量巨大的能源，它安全、清洁、充裕，能提供源源不绝，稳定的能源。
毕业论文风力发电机技能参考文献外文
毕业论文风力发电机技能参考文献外文unanimously approved, has a leading position. Moreover, the small and medium Wind power technology is ultimately distributed independent power supply to meet end-market, rather than large-scale wind power generation and network technologies to meet the domestic monopoly market, technology, update rate must be adapted to a broad and rapidly growing market.3. wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar Energy Technology, combines a variety of applications of new technology, and it covers many areas, the wide range of applications, technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature, most large-scale and industrial development of the industry, separate and individual solar wind has its drawbacks of development, but both wind and solar power complementary combined to realize the two new configuration of energy in natural resources, the technical programs of integration, performance and price compared to aspects of the new energy source for the most reasonable, not only reduces the demand to meet under the same unit cost and expand the scope of application of the market, also increases the reliability of the product.In addition: solar and wind power are both new energy, solar energy than the wind started to be late more than 30 per solar PV / W by the general public about the price of recognition can be converted to a 15% rate;while the price of small wind powerconversion rate is only 1/5-1/6 of the same 60% -80%, only the low price Worse still suppressed, photoelectric production of pollution on the environment greater than wind power, than substantial development in wind energy, this comparison contrast twist of meditation ......, if people use the energy from the point of view, our goal is to meet the electricity from wind power generating capacity to measure the cost of solar energy economy than many .Wind, solar and wind power integration advantages, not only for the 'energy saving, emission reduction,'opened up new horizons for the application of science to meet human needs, for the world to open a fourthRevolution.Second，Wind power has three kinds of operation mode:one is independent operation mode, usually a small wind generators to one or a few families to provide power, storage battery energy, to ensure the electricity without wind, Second is the wind turbines and other power mode (such as engine power), combining to a。
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风力发电技术风能是非常重要并储量巨大的能源，它安全、清洁、充裕，能提供源源不绝，稳定的能源。
目前，利用风力发电已成为风能利用的主要形式，受到世界各国的高度重视，而且发展速度最快。
风能技术是一项高新技术，它涉及到气象学、空气动力学、结构力学、计算机技术、电子控制技术、材料学、化学、机电工程、电气工程、环境科学等十几个学科和专业，因此是一项系统技术，其难度毫不逊色于航天技术。
一、风能技术的划分：风能技术分为大型风电技术和中小型风电技术，虽然都属于风能技术，工作原理也相同，但是却属于完全不同的两个行业：具体表现在“政策导向不同、市场不同、应用领域不同、应用技术更是不同，完全属于同种产业中的两个行业。
因此，在中国风力机械行业会议上已经把大型风电和中小型风电区分出来分别对待。
此外，为满足市场不同需求，延伸出来的风光互补技术不仅推动了中小型风电技术的发展，还为中小型风电开辟了新的市场。
1、大型风电技术：我国大型风电技术与国际还有一定差距。
大型风电技术起源于丹麦、荷兰等一些欧洲国家，由于当地风能资源丰富，风电产业受到政府的助推，大型风电技术和设备的发展在国际上遥遥领先。
目前我国政府也开始助推大型风电技术的发展，并出台一系列政策引导产业发展。
大型风电技术都是为大型风力发电机组设计的，而大型风力发电机组应用区域对环境的要求十分严格，都是应用在风能资源丰富的资源有限的风场上，常年接受各种各样恶劣的环境考研，环境的复杂多变性，对技术的高度要求就直线上升。
目前国内大型风电技术普遍还不成熟，大型风电的核心技术仍然依靠国外，国家政策的引导使国内的风电项目发疯一样在各地上马，各地都期望能借此分得一杯羹。
名副其实的“疯电”借着政策的东风开始燎原之势。
虽然风电项目纷纷上马，但多为配套类型，完全拥有自主知识产权的大型风电系统技术和核心技术少之又少。
还需经历几年环境考验的大型风电技术才能逐渐成熟。
此外，大型风电技术中发电并网的技术还在完善，一系列的问题还在制约大型风电技术的发展。
2、中小型风电技术：我国中小型风电技术可以与国际相媲美。
在本世纪70年代中小型风电技术在我国风况资源较好的内蒙、新疆一带就已经得到了发展，最初中小型风电技术被广泛应用在送电到乡的项目中为一家一户的农牧民家用供电，随着技术的更新不断的完善与发展，不仅能单独应用还能与光电组合互补已被广泛应用于分布式独立供电。
这些年来随着我国中小型风电出口的稳步提升。
在国际上，我国的中小型风电技术和风光互补技术已跃居国际领先地位。
中小型风电技术成熟受自然资源限制相对较小，作为分布式独立发电效果显著不仅可以并网，而且还能结合光电形成更稳定可靠的风光互补技术，况且技术完全自主国产化。
无论从技术还是价格在国际上都十分具有竞争优势；加上现在在国际已打响了中小型风电的中国品牌；“墙内开花墙外香”已愈演愈烈。
在国内最具技术优势和竞争力中小型风力发电一直是被政府和政策遗忘的一个角落，究其原因，在早期国家一直把中小型风力发电定位到内蒙、新疆等偏远地区农牧民使用且归入农机类，价格低廉、粗制滥造、性能可靠度低、安全无保障使用地多为人烟稀少区、国内市场大多都在丧失可靠性的前提下大打价格战；在人们潜意识里形成较差的认识，因此得不到国家的重视和发展。
目前国内中小型风电的技术中“低风速启动、低风速发电、变桨矩、多重保护等等一系列技术得到国际市场的瞩目和国际客户的一致认可，已处于国际领先地位。
况且中小型风电技术最终是为满足分布式独立供电的终端市场，而非如大型风电技术是满足发电并网的国内垄断性市场，技术的更新速度必须适应广阔而快速发展的市场需求。
3、风光互补技术：风光互补技术是整合了中小型风电技术和太阳能技术，综合了各种应用领域的新技术，其涉及的领域之多、应用范围之广、技术差异化之大，是各种单独技术所无法比拟的。
风能和太阳能是目前全球在新能源利用方面技术最成熟、最具规模化和产业化发展的行业，单独的风能和单独的太阳能都有其开发的弊端，而风力发电和太阳能发电两者互补性的结合实现了两种新能源在自然资源的配置方面、技术方案的整合方面、性能与价格的对比方面都达到了对新能源综合利用的最合理，不但降低了满足同等需求下的单位成本，而且扩大了市场的应用范围，还提高了产品的可靠性。
此外：太阳能和风能同属新能源，太阳能比风能起步要晚的多，太阳能光伏发电30元/瓦左右的价格受大众所认可，可转化率仅有15%左右；而中小型风力发电的价格仅为同等的1/5-1/6转化率却有60%-80%，仅此低的价格更有甚者还在打压，光电生产过程中对环境造成的污染远大于风电，却比风电能得到长足的发展，这样的对比反差耐人沉思......，如果从人们用能的角度，最终是为了满足用电，从发电量来衡量风能的成本要比太阳能经济许多。
风光互补整合了太阳能和风能优势，不仅为“节能、减排”开辟了新的天地，以应用科学来满足人类需求，为世界进入第四次革命打开了一页。
二、风力发电有三种运行方式：一是独立运行方式，通常是一台小型风力发电机向一户或几户提供电力，它用蓄电池蓄能，以保证无风时的用电；二是风力发电与其他发电方式（如柴油机发电）相结合，向一个单位或一个村庄或一个海岛供电；三是风力发电并入常规电网运行，向大电网提供电力，常常是一处风电场安装几十台甚至几百台风力发电机，这是风力发电的主要发展方向。
在风力发电系统中两个主要部件是风力机和发电机。
风力机向着变浆距调节技术、发电机向着变速恒频发电技术，这是风力发电技术发展的趋势，也是当今风力发电的核心技术。
下面简单介绍这两方面的情况。
1风力机的变浆距调节风力机通过叶轮捕获风能，将风能转换为作用在轮毂上的机械转矩。
变距调节方式是通过改变叶片迎风面与纵向旋转轴的夹角，从而影响叶片的受力和阻力，限制大风时风机输出功率的增加，保持输出功率恒定。
采用变距调节方式，风机功率输出曲线平滑。
在额定风速以下时，控制器将叶片攻角置于零度附近，不做变化，近似等同于定浆距调节。
在额定风速以上时，变浆距控制结构发生作用，调节叶片攻角，将输出功率控制在额定值附近。
变浆距风力机的起动速度较定浆距风力机低，停机时传递冲击应力相对缓和。
正常工作时，主要是采用功率控制，在实际应用中，功率与风速的立方成正比。
较小的风速变化会造成较大的风能变化。
由于变浆距调节风力机受到的冲击较之其它风力机要小得多，可减少材料使用率，降低整体重量。
且变距调节型风力机在低风速时，可使桨叶保持良好的攻角，比失速调节型风力机有更好的能量输出，因此比较适合于平均风速较低的地区安装。
变距调节的另外一个优点是，当风速达到一定值时，失速型风力机必须停机，而变距型风力机可以逐步变化到一个桨叶无负载的全翼展开模式位置，避免停机，增加风力机发电量。
变距调节的缺点是对阵风反应要求灵敏。
失速调节型风机由于风的振动引起的功率脉动比较小，而变距调节型风力机则比较大，尤其对于采用变距方式的恒速风力发电机，这种情况更明显，这样不要求风机的变距系统对阵风的响应速度要足够快，才可以减轻此现象。
2变速恒频风力发电机变速恒频风力发电机常采用交流励磁双馈型发电机，其结构如图1所示。
它的结构类似绕线型感应电机，只是转子绕组上加有滑环和电刷，这样一来，转子的转速与励磁的频率有关，从而，使得双馈型发电机的内部电磁关系既不同于异步发电机又不同于同步发电机，但它却具有异步机和同步机的某些特性。
交流励磁双馈变速恒频风力发电机不仅可以通过控制交流励磁的幅值、相位、频率来实现变速恒频，还可以实现有功、无功功率控制，对电网而言还能起无功补偿的作用。
交流励磁变速恒频双馈发电机系统有如下优点:允许原动机在一定范围内变速运行，简化了调整装置，减少了调速时的机械应力。
同时使机组控制更加灵活、方便，提高了机组运行效率。
需要变频控制的功率仅是电机额定容量的一部分，使变频装置体积减小，成本降低，投资减少。
调节励磁电流幅值，可调节发出的无功功率；调节励磁电流相位，可调节发出的有功功率。
应用矢量控制可实现有、无功功率的独立调节。
三、风能技术的发展需要不断的创新：目前，我国风能发展中技术创新还很薄弱，缺乏有自主知识产权的核心技术。
因此，在很大程度上还要从国外引进技术。
虽然，在知识经济到来的时代，所有国家都充分利用全球资源，通过技术引进和国际合作来缩小差距，提高竞争能力。
但是，如果没有自主创新能力，就不知道引进什么先进技术，引进以后也没有能力消化吸收，更不能进行再创新，这是一方面；另一方面，国外的核心技术是引进不来的，必须靠自主创新来掌握核心技术；再者，国内的自主创新技术需要政策给予配套、引导、扶持，拥有核心技术的风能产品要加大扶持力度，这样“墙内开花墙外香”的局面才能得以改变，创新的动力才能来自不断的创新。
总之：风电产业中的风能技术已从单一发电向各个需要用电的领域不断的创新，其附加产品也应运而生如:路灯、景观、交通监控、通讯、灌溉、种植、养殖、海水淡化、防火、警报、海岛高山等。
可见风能这个新兴产业的发展能带动了无数个传统产业的发展与转型，而风能在各个领域的应用技术成了这些产业发展的风向标。
即将引发的世界革命必将来自于以风能技术等新能源产业的革命。
Wind Power Generation TechnologyWind is very important and reserves of energy,it is safe,clean,and can provide abundant energy,stability of the stream.Now,use wind power has become the main form of wind,the world's attention,and the fastest.Wind energy technology is a high-tech;it relates more than a dozen of subjects,including meteorology, aerodynamics,structural mechanics,computer technology,electronic control technology,material science, chemistry,electrical engineering,electrical engineering,so the difficulty of a system technology may beyond the difficulty of space technology.First,The division of wind energy technologies:Wind energy technology is divided into large-scale wind power technology and small and medium sized wind power technology,although both are wind energy technology,working principles are the same,the two industries are completely different:specific performance of the"policy orientation is different in different markets,different applications,applied technology is different,totally belong to the same kinds of industries in the two sectors.Therefore,in China machinery industry meeting on the wind to large wind power and wind power to distinguish between small and medium treated separately.In addition,to meet different market needs, extending from the wind and solar technology has not only promoted the development of small wind power technology,but also for the small wind power opens up new markets.rge-scale wind power technology:The technology of large-scale wind power in China still has a certain gap between international.The technology of large-scale wind power technology originated in Denmark and some other European countries,the wind power industry propelled by the government,because of the local wind resource-rich, large-scale wind power technology and equipment ahead of the international development.Our government has also started to boost the development of large-scale wind power technology,and a range of policies to guide industry rge-scale wind power technology are for the large-scale wind turbine design, wind turbine applications for large area on the very strict environmental requirements are applied to limited resources,wind energy resource-rich wind field,to accept a variety of perennial bad environment that something was the complex nature of the environment,high demands on the technology up on the line. Currently large-scale wind power technology in general is not yet ripe,the core technology of large-scale wind power still rely on foreign,national policy guidance to the domestic wind power project launched in various places,like crazy,all over look forward to slice.Worthy of the name"mad electricity"through the wind began to Negative effect and Precaution policy.Although wind power projects have been started,but more as complementary type,complete with independent intellectual property rights of large-scale wind power systems technology and core technology few.The test environment needs to have been a large-scale wind power technology to mature.In addition,the large-scale wind power generation technology and network technology has also improved a number of issues still restrict the development of large-scale wind power technology.2.The technology of small wind power:The technology of small wind power in China could compare with the international technology.In1970s,the small wind power technology in China had been developed which has wind resources for abetter situation,including Inner Mongolia,Xinjiang areas,the first small wind power technology is widely used in power transmission project to the Township for a one of farmers and herdsmen household power supply,continuously updated as the technology improvement and development,not only alone but also with the combination of complementary optical has been widely used in distributed independent power supply. These years as Chinese exports of small and medium wind steadily.Internationally,China's small and medium sized wind power technology and wind and solar technology have leapt to international leadership.Small wind power technology is mature and relatively small by natural resource constraints,distributed independent power as a significant effect not only connected,but also the formation of more stable and reliable combination of optical complementary technologies scenery Moreover,technology is completely self-localization.Both from a technical or price in the international arena are very competitive;with international has now started a small wind power in China brand;"wall flower wall Hong"has intensified.In the country's most technical advantages and competitiveness of small and medium wind power has always been forgotten by the government and policy in a corner of reasons,in the early states has been to locate the small and medium sized wind power in Inner Mongolia,Xinjiang,farmers and herdsmen in remote areas to use and return into the agricultural class,low cost,shoddy,low-performance reliability,security,no security of land mostly sparsely populated areas,most of the domestic market are subject to loss of reliability of large price war;in people subconsciously form a poor understanding of So get national attention and development.Domestic small wind power technology in the"low wind start,low wind speed generation,pitch moment, multiple protection,and a series of technical attention by the international market and international clients unanimously approved,has a leading position.Moreover,the small and medium Wind power technology is ultimately distributed independent power supply to meet end-market,rather than large-scale wind power generation and network technologies to meet the domestic monopoly market,technology,update rate must be adapted to a broad and rapidly growing market.3.wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar Energy Technology,combines a variety of applications of new technology,and it covers many areas,the wide range of applications,technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature,most large-scale and industrial development of the industry,separate and individual solar wind has its drawbacks of development,but both wind and solar power complementary combined to realize the two new configuration of energy in natural resources,the technical programs of integration,performance and price compared to aspects of the new energy source for the most reasonable,not only reduces the demand to meet under the same unit cost and expand the scope of application of the market,also increases the reliability of the product.In addition:solar and wind power are both new energy,solar energy than the wind started to be late more than30per solar PV/W by the general public about the price of recognition can be converted to a15%rate; while the price of small wind power conversion rate is only1/5-1/6of the same60%-80%,only the low price Worse still suppressed,photoelectric production of pollution on the environment greater than wind power, than substantial development in wind energy,this comparison contrast twist of meditation......,if people use the energy from the point of view,our goal is to meet the electricity from wind power generating capacity to measure the cost of solar energy economy than many.Wind,solar and wind power integration advantages,not only for the"energy saving,emission reduction," opened up new horizons for the application of science to meet human needs,for the world to open a fourth revolution.Second，Wind power has three kinds of operation mode:one is independent operation mode,usually a small wind generators to one or a few families to provide power,storage battery energy,to ensure the electricity without wind,Second is the wind turbines and other power mode(such as engine power),combining to a unit or an village or an island power supply,Three is wind power into conventional power operate and to provide electric power grid,is often a wind tens or hundreds of sets installed wind generators,this is the main development direction of wind power.Wind power system in the two main parts is wind machine and generators.Wind turbines to change from adjusting technique,plasma generator toward VSCF technology,this is the development trend of wind power technology is the core technology nowadays wind turbines.The following simple introduction of this two respects.1the change of wind plasma from regulationWind turbines impeller,will capture the wind by converting wind effects on the mechanical wheel torque.Change is the change from adjustment with vertical axis wind leaf surface of Angle,thus affecting the force and the blade,when the wind resistance increases,the output power of the fan is kept constant power output.By regulating mode,fan from the output power curve is smooth.In the rated wind leaf Angle of attack, controller will be placed near zero,do not change,approximate distance equal to adjust for pulp.In the rated wind above,variable structure control function from pulp,adjust the blade Angle of attack,the output power control in near ratings.Change from the wind plasma starting from wind speed is set slurry machine downtime at low impact stress relative ease.The normal work,is mainly adopts power control,in practical applications,power and speed is directly proportional to the set.Small changes will cause the wind changes of wind.Due to the change of wind from pulp by adjusting the impact than other wind from small,can reduce material utilization rate,reduce overall weight.And the change of wind from accommodation type at low speed,can make the blades,keep good Angle of attack than accommodation type stall wind turbines have better energy output,therefore is suitable for low average speed of the region.Change from another advantage of regulation,when the winds reach a certain value,stall type of wind and downtime,must from type machine can gradually changes to the wind load without a blades of open mode,avoid wing,increase of wind turbine.Change is to adjust the defect is sensitive response requires gusts.Because the wind accommodation type stall fan vibration power pulse are small,and accommodation type from wind turbines is bigger,especially for the change from the constant speed windmills way,this kind of circumstance,this does not require more obvious change in the fan is the response speed of wind system to fast enough,can reduce this phenomenon.Third,the development of wind energy technology requires constantinnovation:At present,China's wind energy development in technological innovation is still very weak,the lack of core technologies with independent intellectual property.Thus,much would import technology from abroad. Although the arrival of knowledge economy era,all countries take full advantage of global resources and international cooperation through the introduction of technology to bridge the gap and improve competitiveness.But if there is no capability of independent innovation,not know what the introduction of advanced technologies,are not able to absorb the future,can not carry out another record,which is on the one hand;on the other hand,the core technology is the introduction of foreign countries cannot,and must be rely on innovation to master the core technology;Moreover,the domestic policy of independent innovation of technology needs to supporting,guiding,supporting,with the core technology of wind energy products to be increasing support,such a"wall flower wall incense"situation can be change,innovation and power can come from constant innovation.In short:the wind power industry continuing to creating in a single generation from wind energy technology to power the various areas of need,its additional products have emerged such as:street,landscape, traffic control,communication,irrigation,planting,breeding,sea water desalination,fire,alarm,islands, mountains and so on.Shows the development of wind energy in this new industry can be brought about numerous development and transformation of traditional industries,but the application of wind energy technology in various fields has become the industry's benchmark.World revolution will be caused by wind energy technology from the New Energy and Industrial revolution.。