High frequency IGBT modeling based on datasheet and measurement, and application to analysis of EMI from Inverter

Abstract

According to the technical trends on power semiconductors, the operating frequency of switching devices in power conversion system has been increased for higher power density. The high frequency switching of dc-ac inverter with several switching devices generates large switching noises in output voltage and current, and may cause electromagnetic interference (EMI) problems to other electronic systems. To analyze the high frequency switching behavior of the inverter precisely, an accurate high frequency model of the transistor inside the inverter is essential. In this study, a simple and accurate insulated gate bipolar transistor (IGBT) model based on datasheet and measurement data is proposed and the EMI from a high-power full-bridge inverter is analyzed using the model. The basic operations of IGBT are modeled by MOSFET and BJT components with datasheet information. The parasitic capacitances and parasitic inductances of IGBT module are measured and included in the IGBT model. After exact modeling of the waveform at transition, the results of simulation and measurements of full-bridge inverter are compared in time domain and frequency domain for verification of the proposed model. The simulation results with conventional IGBT model, which have no consideration of parasitic capacitances, are also compared with the measurement data to show the effect of the proposed model. Based on the proposed IGBT model, we analyzed the high frequency characteristics of inverter at turn-off and turn-on transition. In addition, with the inverter circuit composed of the proposed IGBT model, we modeled the wireless power transfer (WPT) system using magnetic field resonance. At last, with the analysis on the WPT system, the current distortion by third and fifth harmonics can be reduced by moving the switching frequency.