Study on mathematical model and sliding mode control for three-level PWM rectifier

The mathematical model of three-level pulse width modulated (PWM) rectifier is established, and the voltage oriented control strategy based on sliding mode control (SMC) is presented in this paper. PI controller is widely used in voltage oriented control, but the dynamic performance of the system is limited by the invariant parameters of PI. In this paper, SMC is introduced instead of conventional PI to obtain fast and accurate response of dc-bus voltage. Simulation results show that with the proposed control scheme, the three-level PWM rectifier realizes the unity power factor, and exhibits better dynamic performance than that of conventional PI controller.