Current harmonics reduction of non-linear load by using active power filter based on improved sliding mode control

Nowadays due to remarkable development of power electronic devices the use of nonlinear loads in power systems has significant growth. These loads produce harmonics in network because of their nonlinear nature. For decreasing harmonic level in the grid, active filter is a desirable device. This paper proposes an improved sliding mode control strategy for parallel active filter which is based on voltage source inverter. This method uses the signs of sliding surface and current to control the filter. The target of this strategy is improving the behavior of source´s current when it is crossing from zero. The proposed active filter is designed and simulated by MATLAB/Simulink and its performance is studied for a sample load. Simulation results show the prominent of proposed control strategy than the sliding mode control method which is based on the signs of sliding surface and voltage.