A novel high‐voltage solid‐state switch based on the SiC MOSFET series and its overcurrent protection

Abstract All‐solid‐state switches are one of the core components of pulsed power supply systems. However, the voltage level of a single switch is limited. By optimizing the chip structure, the voltage level of a single switch can be improved. Due to the immaturity of the production process and the positive correlation between the blocking voltage and the on‐resistance of the switch, it is difficult to improve the blocking voltage and the continuous forward current of a single switch simultaneously. The series‐connected switch is a way to increase the switch's blocking voltage without reducing the switch's continuous forward current. Magnetically coupled isolated drive and resistor‐capacitor forced voltage equalization techniques are investigated to increase the blocking voltage of the switches using multiple SiC metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) in series connections. Meanwhile, a special overcurrent protection scheme is designed to improve the reliability of the series‐connected switch. Finally, a high‐voltage solid‐state switch is developed based on the SiC MOSFET series connections, whose output pulse width is adjustable from 20 to 300 μs, frequency is adjustable from 1 Hz to 3 kHz, the maximum output voltage can reach 57 kV (1 Hz), and the overcurrent protection time is about 1 μs.