A Novel Control Strategy for Shunt Active Power Filter under Nonlinear and Unbalanced Three Phase Load Conditions

In order to overcome the problem of poor filtering by using traditional PI control for dc-link voltage of shunt active power filter (SAPF), an adaptive fuzzy control method is proposed. Firstly, a fuzzy controller is designed which contains two inputs and one output. The two inputs are error and error rate is between reference dc-link voltage and the actual voltage of capacitor, and current amplitude variation of reference power is considered as the output. Then, an adaptive control strategy is proposed to improve the dynamic response of the system and static stability. At last, three phase three wire shunt active power filter under nonlinear and unbalanced load model is built up by using Simulink. Simulation experiment results demonstrate that the proposed method has better dynamic characteristics and lower total harmonic distortion compared with PI control method.