High-voltage high-frequency Marx-bank type pulse generator using integrated power semiconductor half-bridges

This paper discusses the operation of an all silicon-based solution for the conventional Marx generator circuit, which has been developed for high-frequency (kHz), high-voltage (kV) applications needing rectangular pulses. The conventional Marx generator, for high-voltage pulsed applications, uses passive power components (inductors or resistors), to supply the energy storage capacitors. This solution has the disadvantages of cost, size, power losses and limited frequency operation. In the proposed circuit, the bulky passive power elements are replaced by power semiconductor switches, increasing the performance of the classical circuit, strongly reducing costs, losses and increasing the pulse repetition frequency. Also, the proposed topology enables the use of typical half-bridge semiconductor structures, and ensures that the maximum voltage blocked by the semiconductors equals the power supply voltage (i.e. the voltage of each capacitor), even with mismatches in the synchronized switching, and in fault conditions. A laboratory prototype with five stages, 5 kW peak power, of the proposed silicon-based Marx generator circuit, was constructed using 1200 V IGBTs and diodes, operating with 1000 V d-c input voltage and 10 kHz frequency, giving 5 kV/1 A pulses, with 10 mus width and 50 ns rise time