Effects of connection cable length on conducted EMI in electric drives

The paper proposes a SPICE model of an electrical drive motor system that allows prediction of conducted EMI in the presence of long cables. A high frequency model of the power connection between machine and inverter is developed, then a suitable model of the whole system is obtained by connecting the model of the power connection line with a high frequency model of the electric machine and with the circuital model of the power converter. Simulation results of both common mode and differential mode current obtained with different cable lengths, are compared with experimental results achieved on a standard 2 kW induction motor drive.