The Analysis and Compensation of Dead Time Effects in Pwm Inverters

Abstract

In inverters, time delay is inserted in switching signals to prevent a short circuit in the dc link. This causes the dead-time effect, which is detrimental to the performance of inverters. This paper deals with the dead-time effect in pulse width modulated (PWM) inverters. Through the analysis and simulation, it is shown that the effect results in a decrease of the fundamental component and an increase in the low-order harmonics in the output voltage of the inverter. To compen- sate the effect, two simple methods, which are adequate for sinusoidal PWM and memory-based PWM, are presented. The experimental re- sults show the validity of the analysis and the usefulness of the compen- sation methods.