Losses and thermal calculation scheme of IGBT and FWD and its application in PWM inverters for electric engineering maintenance rolling stock

摘要

In this paper, a simple and practical design method of electric engineering maintenance rolling stock (EEMRS) is briefly presented, which is composed of six power units. It is important to improve the energy conservation and efficiency of power converters and reduce the size of the heat dissipation system for EEMRS. Therefore, loss analysis of power semiconductors is very necessary. A new modulating function is proposed on the basis of vector modulation, and the instantaneous power losses and the average conduction power losses in insulated gate bipolar transistor (IGBT) and free‐wheeling diode (FWD) are deduced from the modulating function. Additionally, considering that the junction temperature oscillates with the output frequency, a simple calculation method of the junction temperature ripple is presented, which is helpful in examining the junction temperature limited to the maximum value. Based on the analysis, a heat dissipation system for the direct/alternating current (DC/AC) inverter using forced‐air cooling is designed, and the calculation results and the experimental results are given, which verify the feasibility of the proposed method. ? 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.