Comparison of EMI behavior in inverter and buck-converter operation of power modules by considering the diode reverse recovery effects

In this article the conducted EMI (Electromagnetic interference) differences of power converters are investigated between buck-converter operation and three phase inverter operation. The rising as well as falling edges with different dv/dt caused by inconstant load currents are identified as the main reasons for the differences between the operational modes. The influence of the diode recovery effects to the EMI performance is investigated with different load currents. The mechanisms are interpreted, why the buck-converter operation shows lower conducted EMI compared to inverter operation.