New simplified method for the simulation of conducted EMI generated by switched power converters

A new simplified simulation method for the calculation of conducted electromagnetic interference (EMI) caused by switched power converters (SPCs) is presented. EMI simulation in real SPCs presents particular problems due to complex geometry and the wide range of time constants involved. This makes the computation of EMI a complex matter. The method presented here is based on a "source-propagation-path-derived disturbance" simulation process and is specially designed to simplify the mentioned computation problems. In the design of the proposed method, quick and robust simulations were preferred rather than very accurate results. The resulting models allow quite accurate predictions and sensitivity analysis when certain changes in components or layout are introduced. The paper presents two validation cases, where simulation and experimental results of conducted EMI generated by a general-purpose VSI, with different switching patterns and different layout, are compared.