A novel algorithm for space vector modulated two-stage matrix converter

This paper proposes a novel algorithm for two-stage matrix converter to implement space vector pulse width modulation (SVPWM). Since the two-stage matrix converter has an intermediate dc link, the control process can be decoupled into rectifier stage modulation and inverter stage modulation. Conventionally, PWM algorithm for the rectifier stage is based on two larger source line voltages without zero vectors, which causes the distorted input currents. In this paper, in order to improve the power quality of two-stage matrix converter at input side, SVPWM for input current is applied on the rectifier stage, while the inverter and motor can be seen as constant current load in DC link. And SVPWM for output voltage is applied on the inverter stage. A novel algorithm is proposed to realize the PWM sequence of two-stage matrix converter. The modulation processes of rectifier stage and inverter stage are considered simultaneously and a two-step commutation of zero current switching in rectifier is achieved. Experimental tests have been conducted on a RB-IGBT based two-stage matrix converter prototype. The results verify the good performance of the proposed PWM algorithm with improved input currents.