Self-tuned approximated simplest fuzzy logic controller based shunt active power filter

Abstract

This paper proposes a self-tuned approximated simplest fuzzy logic controller (ST-ASFLC) for shunt active power filter (APF). The approximated simplest fuzzy logic controller (ASFLC) is a 4-rule fuzzy logic controller (FLC), which successfully approximates the control actions of a 49-rule FLC using some compensating factors. The input scaling factors (SFs) of ASFLC are tuned online by a single nonlinear parameter using bipolar sigmoid activation function. The online tuning of SFs of ASFLC results in better dynamic response of shunt APF. The scheme is tested under randomly varying nonlinear loads. The simulation results presented under transient and steady-state operating conditions demonstrate that dynamic performance of proposed ST-ASFLC is better than 49-rule FLC, ASFLC with fixed SFs, and ST-ASFLC using the log sigmoid (unipolar) activation function. The proposed ST-ASFLC shows a remarkable improved performance in terms of peak overshoot, settling time, harmonic mitigation and reactive power compensation over other FLCs with fixed as well as self-tuned SFs using log sigmoid activation function.