Protection apparatus and protection method of PWM cycloconverter

摘要

A protection apparatus and a protection method of a PWM cycloconverter wherein when the PWM cycloconverter is shut off, a surge voltage or an overcurrent is not produced on the output side are provided. A protection apparatus of a PWM cycloconverter is made up of fault detection means 30 for detecting a fault of the PWM cycloconverter, operation stop means 25 for turning off at least some of the uni-directional semiconductor switches 3 to 20 of the PWM cycloconverter if a fault signal occurs, continuous flow means for allowing a load current of the PWM cycloconverter to continuously flow if at least some output phases of the PWM cycloconverter become open, and protection switching means 50 for turning on and off the unidirectional semiconductor switches of the PWM cycloconverter based on the fault signal output from the fault detection means.