Two indirect adaptive fuzzy sliding mode control of three-phase active power filter under different conditions

Abstract

In this paper, two indirect adaptive fuzzy sliding mode control methods are proposed for the current tracking control of active power filter in view of the influence of the parameter perturbation and the unknown disturbance. In the first scheme, a fuzzy system is used to approximate the unknown dynamics in order to eliminate the dependence on the prior knowledge, and another fuzzy system is used to replace the switching control term to reduce the chattering phenomenon. In the second scheme, based on feedback linearization idea, sliding mode controller for active power filter is designed first. Then the fuzzy systems are used to approximate unknown nonlinear functions and the lumped uncertainty which weaken the dependence on mathematical model of the system, effectively improving the system robustness. In the two schemes, the compensation control term is designed based on the fuzzy approximation error estimation, which ensures the tracking performance of the closed loop system. Simulation studies in the MATLAB/SimPower Systems Toolbox demonstrate that the proposed control methods offer a good behavior in both steady state and transient operation during balanced and unbalanced load.