Fuzzy logic controlled shunt active power filter for power quality improvement

The simulation and cxperinicntal study of a fuzzy logic controlled, three-phase shunt active power filter to improve power quality by compensating harmonics and reactivc power required by a nonlinear load is presented. The advanlage of fuzzy control is that it is based on a linguistic description and does not require a niathcmatical niodcl of the system. The fuzzy control scheme is rcaliscd on an inexpeiisive dedicated micro-controller (INTEL 803 1) based system. The conipcnsation process is based on sensing line currents only, an approach different froin conventional methods, which require harmonics or reactive volt-ampere rcquireincnt of the load. The perfʹormancc of the fuzzy logic controller is compared with a convcnlional PI controller. The dynamic behavior of the fuzzy controller is found to be bcttcr than the conventional PI controller. PWM pattern generation is based on carricrlcss hysteresis based current control to obtain the switching signals. Various simulation and experimental results are presented under steady state and transient conditions.