A fixed switching frequency adaptive sliding mode controller for shunt active power filter system

The theory, design and simulation of a fixed frequency pulse width modulation (PWM) based adaptive sliding mode current control for single phase shunt active power filter (APF) to improve power quality is presented in this article. Artificial neural network (ANN) based modified control strategy is being used to control the DC capacitor voltage as well as to generate reference source current. The application of ANN enhances the convergence rate of APF and also makes it adaptive under variable load conditions. The instantaneous phase of the source voltage is extracted by a phase locked loop (PLL). The same phase is used by ANN for calculating the reference source current. That is why the proposed APF is applicable under both nominal and distorted voltage source. The complete non-linear system is analyzed and simulated using MATLAB/Simulink software. Simulation results are presented to validate the theory.