Design and Implementation of an Active Gate Drive Circuit Using General-Purpose ICs for Three-Phase Inverters in Continuous Operation

This paper presents a design and implementation for active gate drive control in a three-phase inverter to achieve both surge voltage reduction and efficiency enhancement. Usually, there is a trade-off relationship between the drain-source surge voltage and the switching losses in switching of power devices, and the appropriate operating point considering the conditions of load, implementation, and temperature, switching characteristics should be selected by choosing specific gate resistance. Although the general gate driver cannot change the gate drivability after the implementation, active gate driving (AGD) can control the gate current or voltage during operation to precisely control the transient phenomenon and is one of the key technologies for improvement of the trade-off relationship. A prototype three-phase inverter for induction motors using a 6 -in-1 SiC power module with six active gate drivers, consisting of only discrete components, was developed. An experimental verification of the effectiveness of AGD in continuous operation was conducted. It is verified that the proposed AGD control reduced the maximum surge voltage while keeping efficiency compared to the conventional gate driving. The proposed AGD circuit is relatively easy to implement and flexibly change the number of gate driver ICs with various gate resistances.