Digital Active Gate Drive with Optimal Switching Patterns to Adapt to Sinusoidal Output Current in a Full Bridge Inverter Circuit

Abstract

Digital active gate drive enables the adjustable driving level in a switching transient for power devices. In this way, it is able to manage switching performance. However, to apply active gate drive in an inverter circuit, the sinusoidal output current turns out a critical problem for the design of driving profile because of its dependency on the load current. This paper aims to validate the feasibility of the digital active gate drive circuit using optimal patterns to adapt to sinusoidal output current of an inverter circuit. Firstly, a look-up table of optimal switching pattern under a certain load current condition was built in advance. It is noted that in the previous work, the online optimization system for finding the optimal pattern has been proposed and it is able to complete the searching of optimal switching pattern in an efficient time. Next, the output current of an inverter has been regulated to a sinusoidal waveform. Based on the output current, the corresponding optimal patterns are referred from the look-up table. Compared to conventional constant driving waveform, the power loss has been successfully reduced by 7% with the full optimal look-up table applied.