501 / 2022-03-22 11:49:37

A Novel High Voltage Solid-State Switch Based onThe SiC-MOSFET Series

SIC MOSFET;,series high voltage switch;,RC forced voltage equalization

Purpose/Aim

High voltage switching device is one of the core components of pulse power system. Solid-state switch represented by field effect device has exclusive advantages over traditional gas switch in high repetition frequency operation, long life, stability and other aspects.  At the same time, the power capacity, switching speed and high temperature resistance of field-effect devices have been improved with the development of silicon carbide and other wide band gap semiconductor materials.  However, due to the limited voltage resistance and impact current resistance of a single device, it is still unable to meet the demands of high voltage switches in pulse power systems, and the limited dynamic voltage sharing capacity of three-terminal devices and the requirements of suspension drive make it impossible to achieve higher blocking voltage through simple series. Through the reliable series connection of devices, the withstand voltage level of devices can be improved economically and efficiently.

Experimental/Modeling methods

In this paper, we studied the magnetic coupling suspension drive, RC forced voltage equalizing, and other methods to realize the effective series of SiC MOSFET, and developed a set of silicon carbide series high voltage switch prototype.

Results/discussion

The prototype’s output pulse width can reach microsecond, frequency is adjustable from 1Hz to 3kHz, and the maximum output voltage can reach 60KV.

Conclusions

This paper studies the driving mode of single signal multi magnetic core, designs a multi switch suspension driving circuit, and is equipped with TVS diode to limit the MOSFET gate voltage and ensure the consistency of each switch driving voltage. The main power circuit realizes the effective series connection of 30 high-voltage SiC MOSFETs through RC forced voltage sharing.