Improvement of four-step commutation strategy for matrix converter based on two line voltage synthesis

Aiming at increasing the safe commutation and improving the quality of output waveform,an improved safe commutation method based on two line voltage synthesis is presented by analyzing the cha-racter of traditional four-step commutation.The improved method includes exchanging the switching PWM sequence and introducing variable commutation time four-step commutation strategy.A simplified method of generating PWM pulse is presented on the basis of two line voltage synthesis strategy.Improved commutation strategy can improve the reliability of commutation,decrease the commutation time and simplify the generation of PWM pulse design.Improved commutation strategy can enhance the quality of output waveform and eliminate the fault of short circuit and open circuit.Finally,experiment results demonstrate the availability and reliability of improved commutation strategy of matrix converter based on two line voltage synthesis.