Fast EMI prediction method for three-phase inverter based on Laplace transforms

The conception of power electronics converters is made without a real EMI prediction method. The classical sizing methods based on experiments are effective but not optimized. They involve the increase in the designing duration and generally lead to the oversize of the filter. To reduce these stages, a mathematical model for the prediction of conducted EMI generated by a three-phase inverter is pointed out in this paper. This model, based on analytical disturbance-sources and propagation paths, including EMI filter and the induction motor, permits the estimation of common and differential modes in all the structure. Passive components and especially the filter elements have been modeled. With this method, the effect of different filter components can be evaluated by simulations. Time domain and frequency simulations are compared and discussed.