Расчет RC-цепей, коммутационных перенапряжений и потерь энергии в тиристорных преобразователях

Abstract

In thyristor converters, abrupt voltage changes occur during switching of valves. The voltages change most significantly when the thyristors are switched off. To limit overvoltage, thyristors are shunted by RC circuits. RC circuits reduce overvoltages, but usually do not eliminate them completely. Switching overvoltages depend on the reverse current in thyristors when they are switched off, on the parameters of the converter circuit and on the parameters of RC circuits. Experimental studies have been carried out and a simulation model with a thyristor rectifier and RC circuits in MatLab-Simulink has been developed taking into account special resonant circuits forming a proper current shape. Calculations of electric processes in the model have been performed. The results of the calculations were compared with experimental data, and a sufficient coincidence was achieved.