Design of Backstepping Direct Power Control for Three-Phase PWM Rectifier

This study focuses on the backstepping control (BSC) design for the direct power control of a three-phase voltage-source pulsewidth-modulation rectifier. The power factor of this three-phase rectifier can be adjusted by controlling the instantaneous reactive power and the dc output voltage simultaneously. In the proposed BSC system with the consideration of system uncertainties, it can be divided into two independent backstepping controllers by introducing two decoupling control signals, and the corresponding controller parameters can be adjusted independently. As a result, both the stable dc-bus output voltage and the sinusoidal input current with a lower total-harmonic-distortion value can be obtained. Moreover, instantaneous active and reactive powers also can be indirectly controlled. In addition, the robustness against power grid fluctuation, step load change, and filter inductance variation can be achieved. The effectiveness of the proposed BSC system is verified by numerical simulations as well as realistic experiments, and its merits are indicated in comparisons with traditional proportional-integral control and proportional-resonant control.