A new dead-time effect elimination method for H-bridge inverters

摘要

Dead-time is added into traditional pulse width modulation (PWM) control to avoid short circuit of DC link of inverters. The dead-time can cause problems such as voltage loss, increasing the value of total harmonic distortion of the current waveform (THDI) as well as output current distortion at the zero-crossing. To solve these problems, many studies have been made to deal with the dead-time issues. This paper presents a novel dead-time effect elimination method for H-bridge inverters based on three-level PWM strategy. In this paper, a new current polarity detection circuit has been used to remove dead-time between signals. This detection circuit is based on the conduction states of two low antiparallel diodes in IGBT modules. Here, only one power supply is needed for the diode states conduction detection. In this paper, the principle of the proposed method is detailed. Moreover, simulation and experimental results are presented to demonstrate the validity of the proposed method.