TS-fuzzy-controlled active power filter for load compensation

This paper describes the application of Takagi-Sugeno (TS)-type fuzzy logic controller to a three-phase shunt active power filter for the power-quality improvement and reactive power compensation required by a nonlinear load. The advantage of fuzzy logic control is that it does not require a mathematical model of the system. The application of the Mamdani-type fuzzy logic controller to a three-phase shunt active power filter was investigated earlier but it has the limitation of a larger number of fuzzy sets and rules. Therefore, it needs to optimize a large number of coefficients, which increases the complexity of the controller. On the other hand, TS fuzzy controllers are quite general in that they use arbitrary input fuzzy sets, any type of fuzzy logic, and the general defuzzifier. Moreover, the TS fuzzy controller could be designed by using a lower number of rules and classes. Further, in this paper, the hysteresis current control mode of operation is implemented for pulsewidth-modulation switching signal generation. Computer simulation results show that the dynamic behavior of the TS fuzzy controller is better than the conventional proportional-integral (PI) controller and is found to be more robust to changes in load and other system parameters compared to the conventional PI controller.