INVESTIGATION ON CURRENT CONTROLLERS FOR MULTILEVEL INVERTER BASED SHUNT ACTIVE POWER FILTER

Abstract

Power electronics technology offers economical and reliable solutions to manage and control use of electrical energy. Which has led to significant use of power electronic systems in industrial and domestic applications. However, power electronics system exhibits nonlinear characteristics, generating current and voltage harmonics in ac power lines and are becoming troublesome problem in ac power lines. Classically, Passive filters have been most commonly used to limit the flow of harmonic currents in distribution systems. But active power filters have emerged as viable alternative to passive filters. Voltage Source Inverters (VSI) with a current control scheme is used for successful operation of the active power filter. Multi-level structure for VSIs is preferred particularly for medium voltage and high power applications. Various current control scheme exists in the literature for control of Active power filter. In this study current controllers for multilevel inverter based Shunt active power filter are investigated. Hysteresis current control, space vector based hysteresis current control and predictive controller are simulated and results and discussion are presented.