风力发电故障诊断

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The geometrical definition of these basic regions is easy when considering the device technological internal description. Figure 5 shows a PINdiode classical doping profile with the different basic semiconductor regions. The PIN-diode bond-graph is then obtained easily (fig 6 ) .
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II
Physical domain
Electrical Thermal Mechanical rotational Hydraulic Mechanical trans1ati on
Flow variable
I
I
Effortvariable
Voltage(V) Temperature
I
Current (A) flow (J 1 K) Angular velocity (rad/s) Volume flow rate (m3/s) Velocity (mls>
variable.wenku.baidu.com
Table 1 shows the flow variable and the effort variable of the main physical bonds. As expected the electrical bond is characterised by the current (flow variable) and the voltage (effort variable).
(K)
Torque (N.m)
Pressure (N/W Force (N)
I1 - The basic of bond graph techniques [8]
The bond graph techniques are a generalisation of the Kirchhoff networks and are principally used in Automatics. They are based on several main principles. The bond between elements A and B indicates the direction of the energy flow and it must be completed so as to explain which of the two elements is controlling the effort and the flow : this is the causality information. Evidently an element cannot control both the flow and the effort. Thus if the element A is controlling the flow then the element B will control the effort, and vice-versa. A causal stroke graphically indicates this property. It is a short perpendicular line made at one end of a bond (fig 2). The causal stroke indicates the direction in which the effort variable is directed. In figure 2 the effort variable is directed from the element B to the element A , thus the element A is said "to be controlling" the flux variable.
POWER ELECTRONIC CIRCUIT SIMULATION USING BOND GRAPH AND PETRI NETWORK TECHNIQUES
Bruno ALLARD, Herv6 MOREL and Jean-Pierre CHANTE
fax : (+33) 72.43.85.30
The classical regional hypothesis helps to divide a power semiconductor device in basic semiconductor regions : . ohmic region (Q), . drift-diffusion balance region . space-charge region (SCL), . high-level injection region (HLI) ...
CEGELY (URA CNRS 829), INSA Lyon b6t. 401,69621 VILLEURBANNE - FRANCE
e-mail : allard@cegely.insa-lvon.fr
Abstract - We have successfully applied bond graph techniques to power semiconductor device modular modelling. But applying bond graphs to power electronic circuit modelling introduces the problem of causality switching due to semiconductor device behaviours that vary. Also using Petri nets to describe these behaviour exchanges and the bond graph causality analysis allows to build the system main Petri net. Hence this method is an efficient and hierarchical modelling frame. The bond graph represents the system transient behaviour and the Petri net is in charge of the system functional behaviour.
I Introduction
Analogue circuit simulations are principally performed by Spice-like simulators. But this kind of simulation generally looks non-satisfying in power electronic field. Most of the time the designer is condemned to use ideal switches instead of semiconductor devices because the main default of Spicelike approach is surely the empiricism and the inaccuracy of the models when dealing with power devices. Thus there is a real effort for more-physical model development [ 1-71. We have proposed a semiconductor device modular modelling method based upon the bond graphs : techniques of Automatics [8]. These techniques already lead to good simulation results and their general frame allows to think about numerous further improvements.
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fig 1 : graphical definition of the bond between elements A and B. Inside any physical system parts can be isolated that exchange information. An hypothesis is that these flows of information are always associated toflows of energy. Thus a
0-7803-1243-0~3$03.00 0 1993 IEEE
fig 2 : graphical indication of the bond causality. A controls the flow, B controls the effort The consistency analysis of all the bond causality enables to study the role of each component inside a circuit : it is called the causality analysis. These are the component state-variable model equations that impose to respect rules for the causality of each bond connected to the component. In addition to Kirchhoff network classical components (R, L, C, current and voltage sources...) and in order to complete the drawing of the bond graph of an electrical circuits, two special components must be introduced that ease the connection between the circuit elements : * a "0"junction ( 0 on fig 4) denotes an electrical parallel combination for example, * a "1" junction (0 on fig 4) denotes an electrical series combination. The derivation of the bond-graph in figure 4 from the circuit in figure 3 is fully described in [8].
bond graph shows how energy is flowing between the system parts while each part state-variable model shows how energy is stored inside the part. An energy flow is called a bond and graphically an half-arrow indicates the direction of the flow between two elements (fig 1). The energy flow can be of any nature (electrical, thermal, mechanical...) but it is always characterised by the value of a power that is the product of aflow variable by an effort