Identification of the Common Mode Impedance of a Microgrid DC-DC Buck Converter in Normal Service and under Insulation Fault

In this paper, we identify the common mode impedance of a parallel converter cell and the impact of each converter on the entire system. The study is done in two cases, favorable when all the sane converters, and degraded when at least one converter in insulation fault. We also put the distinction load type to see their effect on the propagation path. The equivalent method of the Thevenin and impedance circuit is used for the prediction electromagnetic interference generated by these converters. The good knowledge of these electromagnetic interferences allows a proper optimization of the filters (volume/efficiency), and the optimum choice of exploitation of the whole of the cell. The model is tested by PSpice simulation with a wide frequency range up to 30 MHz.