Study on the control strategy of three-level PWM rectifier based on SVPWM

The three-level PWM rectifier topology has been studied in this paper, and the decoupled state-space equations in synchronous rotating reference frame (d-q frame) were derived. The hierarchical controller structure is adopted, namely, the inner current-loop is responsible for reference current tracking and the outer voltage-loop is responsible for load regulation. The design methodologies for proportional-integral (PI) controllers are presented, for the inner current-loop and outer voltage-loop, respectively. The proposed three-level PWM rectifier based on space vector pulse-width-modulation (SVPWM) strategy is simulated using MATLAB/SIMULINK. Simulation results demonstrate that the proposed three-level PWM rectifier provides excellent performance both in steady-state and dynamic load variations. Pure sinusoidal waveforms can be achieved in grid currents with a unity power factor. Besides, energy feedback is realized.