Vector control of three-phase voltage source PWM rectifier based on fractional-order controller

In this paper, the dual closed-loop vector control of the three-phase voltage source pulse-width modulated (PWM) rectifier based on fractional-order controller is studied. The classical proportional integral (PI) controller is used in the inner current loop. The feed-forward decoupling control method is established to regulate active currents and reactive currents. In this way, a power factor of the system is close to one. The fractional-order controller is used in the outer voltage loop to stable the direct current (DC) output voltage. It can enhance the robustness of the system, weaken impacts from the load disturbance and the grid disturbance to the output characteristics of the system, and ensure that the DC voltage remains stable with the parameters changing. Correction method which combining the frequency-domain analysis and flat phase condition is used to tuning the fractional-order controller. Through theoretical analysis and simulation research, we proved that the method enhances the immunity and robustness of the system. With the virtue of faster respond and less overshoot, it can get better control effectiveness.