Fuzzy Control and Lyapunov-based Stability Control of the Three-phase Shunt Active Power Filter

摘要

When the load and system parameters are changing, the APF usually appears unstable and its exact mathematical model is quite difficult to determine. This study is to introduce Takagi Sugeno (TS) type fuzzy control ler and Lyapunov-based stability theory into the Direct Current (DC) side voltage control and current control of the three-phase Active Power Filter (APF), aiming to guarantee the precision and stability of APF. Firstly, the TS fuzzy control is applied to voltage error and error rate at DC side to attain the source current amplitude of reference value; then the Lyapunov method is adopted to design the switching function of APF and the global stability of control system is ensured by insuring the derivative of energy-like Lyapunov function always negative. The parameters of TS fuzzy control ler are optimized by using Adaptive Neuro-Fuzzy Inference System (ANFIS) in Matlab/Simulink. As the results of comparative tests show, the proposed method can guarantee the precision and stability of APF under the conditions of varying load and system parameters.