Quantitative Estimation of Conducted Emission from an Inverter System

Abstract

This paper proposes a method for quantitative estimation of conducted emission from an inverter system, which helps the optimal design of EMI filters. The basic concept of the proposed method is the usage of a circuit simulator with detailed modeling of the components of the inverter system, i.e. passive devices, switching devices, and measurement instruments. The proposed method provides the conducted emission of the inverter in the form prescribed in CISPR 22, that is, the simulation results can be compared to the experiments directly. It is revealed that the simulation result agrees very well with the experiment with the error of ±6dB ranging from 150kHz to 5MHz. A great benefit from the proposed method is that the mode separation, differential and common, of the conducted emission becomes possible. Discussions and analyses are set forth in this paper with making full use of this benefit, which greatly makes the design of the EMI filter efficient.