Self controlled invertor system - has extinguishing capacitor whose charging half-wave is initiated by ignition of auxiliary diode

摘要

The invertor has two main thyristors and two antiparallel diodes in each phase, whose junction points serve as phase terminals and are connected to a commutation device. It consists of an extinguishing capacitor in series with a commutation inductor, and two antiparallel extinguishing diodes. The commutation device is connected to the junction point of first electrodes of two capacitors connected in series, whose second electrodes are connected through a further commutation inductor to the main thyristors and also to a terminal of a d.c. source. The extinguishing capacitor (10) is connected to the positive and negative terminal of auxiliary d.c. voltage source (20) through an additional controllable diode (17, 18) in series with an additional auxiliary inductance (15, 16). Charging half-wave for the extinguishing capacitor (10) is initiated by ignition of the corresponding additional auxiliary diode (17, 18).