EMI Estimation for DC/AC Hard Switching Converter Using Wiener Filter

Abstract

This paper describes how the use of a specific signal processing method can help to estimate and understand the Electromagnetic Interference (EMI) generation of a switched mode power supply. This method allows to estimate, from EMI measurements, the different transfer functions between each source of disturbance and the disturbances themselves. Thus, the EMI signals is decomposed and combined with independent source of disturbances. This method is based on the redefinition of the voltage source inverter switching states, and on the Wiener filtering theory. This new tool for fast EMI estimation and prediction is first described, and its performance is illustrated on simulated and measured data.

The Wiener Filter Applied to EMI Decomposition

“…Therefore, in this paper, the perturbation reconstruction based on a DSP method-the Wiener filtering (WF) concept-is applied. The source identification method is used for determining the transfer function between the source and generated perturbations [13]. The proposed WF method applied to conducted EMI analysis allows one to numerically separate noise from more than one sources, and investigate an impact of each source and also the level and the propagation path of the perturbation.…”