Switching Transient Traced Scheme Based on Sinusoidal Waveform to Reduce EMI for IGBTs

High-speed and continuous switching actions of power semiconductor devices is the main source of EMI in power electronic converters. If the switching speed is reduced, then the EMI emission level can be reduced, but the longer switching transient increases the switching loss. For a fixed switching period, reshaping the waveform of the switching transient to reduce EMI is preferred. Therefore, this paper analyzes the influence of the switching waveforms on the spectrum, and points out the relationship between the derivable order of the switching waveform and the spectrum in high frequency. Then, the switching transient based on sinusoidal waveform is applied and an active gate drive scheme based on closed-loop control is designed for IGBTs. Finally, experiments verify the switching transient tracking performance of the control scheme and the effectiveness of reducing EMI based on the sinusoidal switching transient.