VOLTAGE ON THE POWER ELECTRIC DIODES OF A THREE-PHASE BRIDGE COMPENSATION CONVERTER WITH ONE COMMUTATING LINK

Abstract

The operating conditions of power electric diodes of a three-phase bridge compensation converter with one commutating link, which consists of a three-phase capacitor battery and a three-phase group of fully controlled devices, are investigated. This technical solution makes it possible to ensure the recharging of the capacitors of the commutating link and the control of the energy process of the converter. At the same time, the operating conditions of its power equipment also change. The main content of the study is the analysis of the components of the reverse voltage of the power electric diodes of the compensation part of the converter and the dynamics of its change during the regulation of the electromagnetic process by transistors of the commutating link. This is required when determining the class of diodes in the case of introducing a converter according to the scheme under study into production. The study of the magnitude and form of the reverse voltage was carried out for two modes: the transistors of the commutating link are controlled within the framework of the operation of the power electric diodes of their phase and the next one. The volume of research is limited to the analysis of processes at a single frequency of control pulses. As a result, it was proved that on the power electric diodes of the compensation part of the converter, the reverse voltage is less than on other valves. The reason for this is the commutating voltage of the capacitors, which, superimposed on the line voltage of the secondary winding of the converter transformer, reduces the maximum value of the reverse voltage curve of the electric diodes.