Implementation of 3-Level Active Shunt Power Filter using Conventional Hysteresis Controller

Abstract

Non-linear load has caused a fluctuating and harmonic currents which resulted low efficiency, poor power factor, additional losses and overheating of equipment that lead to the degradation of power quality. The active power filter is effectively compensates the current harmonics and reactive power at point of common coupling by inject compensating currents in to the source to cancel the harmonics contained in the load current. It is achieved by using Instantaneous Reactive Power Theory (PQ theory) and Fryze Current Computation Technique. Voltage source inverter(VSI) based SAPF’s are widely used for compensating the load current harmonics, improving the power factor for nonlinear loads. This VSI switching signals are generated through advanced three-level hysteresis current controller (HCC) that achieves significant reduction in the magnitude and variation of the switching frequency improved performance. The adaptive hysteresis band current controller changes the hysteresis bandwidth according to modulation frequency, supply voltage, DC capacitor voltage and slope of the reference compensator current wave.