Elimination of Dead-time in PWM Controlled Inverters

A dead-time elimination method is presented in this paper for PWM controlled inverters. In comparison to using expensive current sensors, this method precisely determines the load current direction by detecting the operating conditions of active devices and their anti-parallel diodes. A low-cost diode-conducting detection circuit is developed to measure the operating status of the anti-parallel diode. In comparison with complicated compensators, this method features with simple logic and flexible implementation. This method significantly reduces the output distortion and regains the RMS value. The principle of proposed dead-time elimination method is described. Simulation and experimental results are given to demonstrate the validity and features of the dead-time elimination method.