This paper presents the modelling and simulation of a three-phase four leg shunt active power filter (SAPF) using artificial neural network (ANN) based synchronous reference frame theory (SRF) in the dq0-axes for power quality improvement. It is used for harmonics and zero-sequence current elimination, and reactive power compensation under unbalanced nonlinear loads. Backstepping regulators are used to control the reference currents and the dc bus voltage of four leg inverter based SAPF to robustness, stabilizing the system and to improve the response and to reduce the overshoot and undershoot of traditional proportional-integral (PI). The success of the proposed control is demonstrated through simulation using MATLAB SIMULINK.

Keywords: Four-leg shunt active power filter, Synchronous reference frame (SRF) theory, Artificial neural network (ANN), Backstepping, 3D space vector modulation (SVM), Harmonics, Zero sequence current