Development of an Active dv/dt Control Algorithm for Reducing Inverter Conducted EMI with Minimal Impact on Switching Losses

This work investigates the use of an active gate control circuit to reduce the EMI produced by switching power converters. The active gate drive circuit makes it possible to adjust the voltage transition rate of a MOS-gated semiconductor switch on a pulse-by-pulse basis during PWM operation. This paper shows that tailored application of this circuit in a hard- switched inverter can be used to reduce the conducted common- mode EMI generated by the inverter while minimizing the incremental increase of the switching losses produced as a result of this control. An active dv/dt control algorithm that has been developed for a three-phase inverter to achieve this EMI reduction has been implemented for testing. Experimental results show that EMI can be reduced using this active dv/dt control algorithm with lower total switching losses than a scheme that achieves a similar EMI reduction using adjustment of the gate drive resistors alone.