High order Sliding Mode Control for shunt Active Power Filter

The aim of this paper is to present the implementation of a shunt Active Power Filter (APF) to reduce the harmonic distortion in the current of a voltage node feeding a nonlinear load. A two-level three-phase Voltage Source Inverter (VSI) is used for the APF. The control methodology employed is based on a high order sliding mode algorithm known as Super-Twisting. Simulation results are presented that confirms validity of the proposal.

I. Introduction

Harmonic distortion of voltage and current in an electrical system are caused by nonlinear loads, and can result in overheating, overload, resonance and power losses in transformers and electrical machines. These effects can reduce the life span of electric equipment, increasing failure occurrence and costs. For electrical distribution networks, passive filters built using RLC components are common to reduce harmonic distortion; their tolerance for high levels of voltage and current makes them suitable for this application. However, active power filters have advantages over their passive counterparts [1]; for example, passive filters require a comprehensive study of the system where they are going to be placed, otherwise, resonance and low effectiveness can result. A comparison between passive and active filters has been made in [2], where it is shown that correct implementation of an APF outperforms that of a passive filter.