Control and Protection Strategy Design of IGBT Switch for Pulsed Electrostatic Precipitators

Pulsed power supply can provide high voltage pulse into electrostatic precipitator (ESP), which could reduce emissions particularly in high specific resistance soot industry field. In order to increase the reliability of the power system, a method of IGBT soft switching and overcurrent protection is proposed. The detection circuit hardware was designed to recognize IGBT overcurrent stage and IGBT soft turn-off timing. Control logic which is realized based on CPLD and DSP make the IGBT drive signal respond quickly. In additional, RCD absorption circuit makes a pivotal function in IGBT turning off process. Spark protection strategy is designed to make sure the safe operation. Feasibility of this strategy is verified by PSIM and prototype experiment.