power electronics Capacitors

The service conditions depend on the temperature of capacitors. The capacitors must not be used near sources of heat. After installation it is necessary to check whether the case temperature is lower than max. service temperature at the highest service load (voltage, current, temperature of cooling air). The capacitors must not be placed near the high current conductors in order to avoid post-heating by eddy currents. They shall be mounted in vertical position. Connecting conductors have to enable the movement of capacitor lid about 20 mm upwards because of propper function of the overpressure disconnector.

Commutating capacitors are self-healing, MKV system. The case is cylindrical with mounted or soldered bushings. An overpressure disconnector is fitted in. PP film dielectric is impregnated with mineral oil. The electrodes are made of double-sided metallized capacitor paper with reinforced edges. Self-healing ability together with complete impregnation guarantees high voltage loading of capacitor, low losses are achieved by using PP film dielectric.

The capacitors are applied in forced commutation convertors. Together with other components in curcuit they ensure thyristor switching off.

Application

Commutating capacitors