电气专业中英文翻译

The report concludes

The report mainly collected from the power transmission and power system requirements related to the content of these two

areas, and analyze, to understand some of the relevant knowledge.

Page2 Electrical Energy Transmission（电能输送）

1 English text

From reference 1

Growing populations and industrializing countries create huge needs for electrical energy. Unfortunately, electricity is not always

used in the same place that it is produced, meaning long-distance transmission lines and distribution systems are necessary. But

transmitting electricity over distance and via networks involves energy loss.

So, with growing demand comes the need to minimize this loss to achieve two main goals: reduce resource consumption while

delivering more power to users. Reducing consumption can be done in at least two ways: deliver electrical energy more efficiently

and change consumer habits.

Transmission and distribution of electrical energy require cables and power transformers, which create three types of energy loss:

the Joule effect, where energy is lost as heat in the conductor (a copper wire, for example); magnetic losses, where energy dissipates into a magnetic field;

the dielectric effect, where energy is absorbed in the insulating material.

The Joule effect in transmission cables accounts for losses of about 2.5 % while the losses in transformers range between 1 % and

2 % (depending on the type and ratings of the transformer). So, saving just 1 % on the electrical energy produced by a power

plant of 1 000 megawatts means transmitting 10 MW more to consumers, which is far from negligible: with the same energy we can

supply 1 000 - 2 000 more homes.

Changing consumer habits involves awareness-raising programmers, often undertaken by governments or activist groups. Simple

things, such as turning off lights in unoccupied rooms, or switching off the television at night (not just putting it into standby

mode), or setting tasks such as laundry for non-peak hours are but a few examples among the myriad of possibilities.

On the energy production side, building more efficient transmission and distribution systems is another way to go about it. High

efficiency transformers, superconducting transformers and high temperature superconductors are new technologies which promise

much in terms of electrical energy efficiency and at the same time, new techniques are being studied. These include direct current

and ultra high voltage transmission in both alternating current and direct current modes. Keywords: electrical energy transmission

From reference 2

Disturbing loads like arc furnaces and thyristor rectifiers draw fluctuating and harmonic currents from the utility grid. These non

sinusoidal currents cause a voltage drop across the finite internal grid impedance, and the voltage waveform in the vicinity becomes

distorted. Hence, the normal operation of sensitive consumers is jeopardized.

Active filters are a means to improve the power quality in distribution networks. In order to reduce the injection of non sinusoidal

load currents shunt active filters are connnected in parallel to disturbing loads (Fig. 1). The active filter investigated in this project

consists of a PWM controlled three-level VSI with a DC link capacitor.The VSI is connected to the point of common coupling via a

transformer. The configuration is identical with an advanced static var compensator.

The purpose of the active filter is to compensate transient and harmonic components of the load current so that only fundamental

frequency components remain in the grid current. Additionally, the active filter may provide the reactive power consumed by the

load. The control principle for the active filter is rather straightforward: The load current ismeasured, the fundamental active

component is removed from the measurement, and the result is used as the reference for the VSI output current.

In the low voltage grid, active filters may use inverters based on IGBTs with switching frequencies of 10 kHz or more. The harmonics