An overvoltage driver with inductive adder pulse for fast switching of series-connected MOSFETs module

A novel overvoltage driver is proposed to speed up the turn-on transition of series-connected MOSFETs module which serves as the main switch in high voltage pulse generator. In order to realize the overvoltage driver, a nanosecond pulse with the amplitude of hundreds of volts is superposed on a square driving signal by linear transformer driver scheme. The results show that, comparing to the commercial high current driver, the turn-on time of a 10kV MOSFETs module including ten devices with the proposed driving scheme can be shortened from similar to 25ns to similar to 7ns. The proposed overvoltage driver can be used to conveniently modulate the rise time and pulse width of high voltage nanosecond pulse generator constructed by MOSFETs. In addition, it is demonstrated that there is almost no influence of the overvoltage driver on the gate-source characteristics of device by analyzing the variation of C-f curves of input capacitances.