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

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 mu s, 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 mu s.