Nonlinear PI control for three-phase PWM AC-DC converter

This paper proposes a nonlinear PI control strategy for three-phase PWM AC-DC voltage source converter. The nonlinear controller, consisting of the special nonlinear function of the error and the traditional PI regulator, improves the DC voltage response as well as the robustness against the load uncertainty. In addition, the sinusoidal AC current and unity power factor is achieved. This controller is also easy to be realized. The simulation and experimental results are provided to verify the validity of the proposed control algorithm.