LOSSES CALCULATION OF PWM INVERTER

Abstract

A crucial criterion for the dimensioning of converters is the cooling of the power semiconductors and thus determination of power dissipation in the semiconductors at certain operating points. Estimation of its temperature rise of power electronics devices are generally evaluated based on its thermal equivalent circuit. These equivalent circuit models typically composed to thermal RC networks, to the calculated power losses. Methods for the calculation and simulation of semiconductor losses in the converters are well known. In this paper an attempt has been made to calculate power semiconductor losses for Pulse with Modulation(PWM ) Inverter. Conduction losses as well as switching losses are included in the calculation using a simplified model, based on power semiconductor data sheet information. Proposed simulation scheme calculates losses with minimum efforts, high accuracy and does not slow down the numerical simulation. It can be embedded directly in any circuit simulator employing ideal switches. Results of the calculation are shown for PWM inverter. As an example, a PWM Inverter is connected to drive a simple resistive load, where the losses calculations are based on datasheet values. Based on these calculations, result of temperature rise of semiconductor devices shown.