Design of a new protection circuit in high-voltage solid state modulator

In view of the problems in the use of high-voltage solid-state modulator, this paper analyzes the causes of its failure, and proposes a compound protection circuit. On the one hand, the synchronous transformer is introduced to realize the synchronous transmission of driving control signals, so that the trigger of the switch tube is consistent, and the combination of static voltage sharing and dynamic voltage sharing is adopted to realize the partial voltage balance of the switch tube and ensure the normal operation of the switch tube. On the other hand, the over-current detection and protection circuit is designed to cut off the driving pulse quickly when the arcing is started, so as to effectively protect the modulator and load. Through experiments, the results show that the technology can effectively balance the power side voltage of each IGBT, and quickly turn off the pulse voltage in case of over-current fault. The superiority of this method is verified by experiments.