Dead-time compensation method of restraining zero-current clamping effects for VSI

Voltage source inverter(VSI) has some problems caused by dead-time effects,such as phase-voltage and phase-current distortions,zero-current clamping effects,etc.To solve the problems,dead-time effects and zero-current clamping effects were analyzed,a main cause of zero-current clamping effects was found,and then a dead-time compensation algorithm was proposed.The algorithm doesn't have to check current polarity.Based on space vector pulse width modulation(SVPWM),the dead-time compensation time was distributed to compensate two non-zero space voltage vectors according to their effective acting time ratio in every PWM period,and the dead-time compensation time was obtained by offline measurement.Experimental results demonstrate that the proposed algorithm remarkably suppresses low-frequency current harmonic,effectively restrains zero-current clamping effects,greatly minimizes current distortions,and improves operation performance at low speed.