Current-Loop Gate-Driving Circuit for Solid-State Marx Modulator With Fast-Rising Nanosecond Pulses

When designing solid-state Marx modulators (SSMMs) with fast-rising nanosecond pulses, the gate-driving scheme for pulse discharge switches is one of the most important aspects to be considered. In this article, we propose a nanosecond current-loop gate-driving circuit for a synchronized fast gate drive of pulse discharge switches. The proposed circuit comprises an inverter, a current-loop cable, and discharge switch drivers. The inverter generates bipolar pulses that simultaneously provide driving power and fast triggering signals to all discharge switch drivers through the cable. The triggered discharge switch drivers rapidly turn on / off all discharge switches with accurate synchronization. In the inverter and discharge switch drivers, the fast gate-driving methods were used to overcome parasitic inductances and realize nanosecond operation. The concept and operational principles of the proposed gate-driving scheme are presented. To validate the performance and reliability of the SSMM using the proposed current-loop gate-driving circuit, a laboratory test on a 10-kV-70-A-50-kHz SSMM prototype was conducted, and the results were discussed.