A Novel Method for Estimation of IGBT Switching Losses in Voltage Source Convertors through EMT Simulations

This paper introduces a simplified method for estimating switching energy losses in an IGBT device of a Voltage Source Converter (VSC) using Electro-Magnetic Transient (EMT) simulations. By considering the switching process as characterized by an equivalent circuit model of a unit cell that represents one leg of a VSC, equations are derived to evaluate the switching losses at different load currents. The computational effort needed to estimate switching loses with the proposed method is much less than the effort required when using the detailed dynamic models of IGBT. But the accuracy of the loss estimations obtained with the proposed method is comparable with those obtained with a detailed model. Furthermore, all parameters in the loss equations can be found using only two measurements taken at two different load currents.