LCL-type Grid-Connected Inverter Based on Fractional-Order PID Control

The main function of Grid-connected inverter is to convert the DC power to AC power with stably, generally, the quality of output power is controlled by the traditional PID controllers. However, some results of steady-state control with low precision and larger ripples appearing in this control process. Therefore, a new fractional order PID control strategy is proposed. The development of Fractional order PID controller is based on the traditional PID controller. Compared with traditional PID controller, the fractional order PID controller has two more adjustable parameter. It can be designed more flexibly and better performance. The simulation results show that the fractional order PID control strategy improves the steady - state accuracy of the output current of the grid - connected inverter obviously, besides, it has good control effectiveness, flexible structure, and strong ability of anti-interference.