Dead-Time Elimination Method of High Frequency Inverter with SHEPWM

Selective harmonic elimination pulse width modulation(SHEPWM) inverter can eliminate harmonic effectively in theory, but dead-time increases the harmonic component in output voltage. Based on its operating principle, the advance-off mode is taken as an example to analyze the influence of dead-time on SHEPWM inverter, and the waveform figures and output harmonics amplitude equations which take account of the influence of dead-time are obtained. In this paper, a new method for inverter dead-time elimination with no current sensor is studied. Compared with the traditional dead-time compensation method, the proposed method only needs to add a fixed dead-time pulse to the output current of the inverter when the current polarity changes, which can greatly reduce the number of dead-time pulse, so as to reduce the influence of the dead-time. The simulation results show that the elimination method can effectively reduce the waveform distortion caused by the dead-time.