سال انتشار: ۱۳۸۰

محل انتشار: شانزدهمین کنفرانس بین المللی برق

تعداد صفحات: ۵

نویسنده(ها):

Alexandrov – Saint-Petersburg state Technical University Russia

چکیده:

The main problem of electrical power system operating is the compensation of a reactive power which is created by electromagnetic field of transmission line. As a matter of fact that this reactive power varies in wide range from the power of the electrical field of lines by idle regime of their operation up to zero by surge impedance loading (SIL) and it increases when transmitted power is lager than SIL in accordance with the surplus power of a magnetic field of lines. For this reason in order to provide a correct compensation of the reactive power in electrical networks it is necessary to utilize controlled compensators, which are able to consume and to generate reactive power . In order to limit switching overvoltages, which appear by commutation of lines, such compensator is to be fast-acting in order to change its capacity during the process of a circuit-breakers operation. Controlled compensator of a reactive power consists of the closed magnetic conductor without gaps, control winding which is disposed around of the main limb of a magnetic conductor, compensating winding which is disposed around of control winding , network winding, which is disposed around of compensating winding, and control system. The network windings (NW) is connected with high
voltage conductor always. Control winding is connected with thyristor’s valve . By means of variation of its firing angle it is possible to vary the current through control winding and respectively through the network winding. And in order to damp highest harmonics in NW compensating winding (ComW) is utilized. Tree angle connection of these windings provides the damping of third harmonic. In order to damp 5-th and 7-tharmonics it is necessary to use special filters, which consist of series connected capacitors and chokes with the ratio between capacitance Ck and inductance Lk in accordance with the relation