Features of the High-Voltage Swithes (Commutators) Used on IGBT Modules

The paper discusses the usage of pulse current commutation switches in the experimental-design work on constructing a high-voltage test facility to test varistors with current pulses of amplitude from 150 to 10000 A. Initially, a switch with the pulse thyristors (TI243-400-40) was used in the facility. However, as proved by full-scale measurements, it failed to provide a sufficient rate of the rise in the pulse current at small amplitudes. To get the required pulse current waveform, we designed and constructed a modification of the commutation switch with high-voltage IGBT transistors MTKI-500-65-2NTV produced in Russia. The system for turning on transistors with 12000 V galvanic isolation was developed as well. To avoid switching overvoltage when the current is interrupted by transistors, the transistors are turned off only after the current pulse terminates. This technical solution is described in detail in this article. The electrical circuit and photograph are given in the text. There are also graphs that describe the ongoing processes.