Predictive Current Control for Three-Phase Z-Source PWM Rectifier

Three-phase z-source PWM rectifier is a single-stage system. The rectifier can buck and boost input voltage and improve the reliability. In this paper, a predictive current control strategy based on instantaneous power for z-source rectifier is presented for simpler system structure. The proposed system consists of three-closed-loop controller. The first controller is built on the discrete mathematical model, and source current can be predicted by minimizing a chosen cost function in one period. The second controller is used to regulate voltage of dc-link capacitor. Shoot-through duty ratio is achieved by the final controller, whose input signal is a difference between reference and actual output voltage value of z-network capacitor. Space vector pulse width modulation with shoot-through zero state is adopted to implement current predictive control. Simulation results demonstrate that the proposed system has better static and dynamic characteristics.