Abstract: The SPWM inverter used in DC-link VSCF electrical power system is dealt with. With the numerical analysis of the process of Natural Sampling SPWM, the relation between the harmonic spectrum of inverter output and the parameter M, N is obtained. The influence of the storage time T. and the turn-on delay time ta on the spectrum is also taken into account in the analysis. The comparison of several kinds of power devices leads to the selection of power MOSFET to compose the SPWM inverter used in VSCF system with a small capacity. Two high-efficiency Gate drive circuits for power MOSFET and the test characteristics of SPWM inverter is presented in the paper.

Key words: VSCF electrical power, inverter, power MOSFET