An Improvement of Surge Voltage and Efficiency in Three-Phase Inverter by Using Fully Digital Active Gate Control

Abstract

This paper presents a control method of fully digital active gate drivers to simultaneously realize surge voltage reduction and efficiency enhancement in a three-phase inverter for motor drive applications. Generally, the surge voltages of power devices in each switching are affected by the operation principle of the three-phase current values and phases. In the proposed method, the active gate driving patterns of fully six gate drivers are suitably changed according to the phase angle of the three-phase current to minimize the highest surge voltage and the switching loss in a fundamental period. A prototype of the three-phase inverter using a 6-in-1 SiC power module and six digital active gate driver ICs was developed to verify the improvement effect of the proposed active gate control. It was experimentally shown that the surge voltage could be reduced from 418.6 V to 369.4 V, fixing a high efficiency.