Power quality improvement using multilevel inverter as series active filter

This paper presents a Cascaded H-Bridge Multilevel inverter based series active filter intended for installation on industrial and utility power distribution systems. The control strategy based on Synchronous Reference Frame theory is designed so that the voltage injected by active filter is able to mitigate the voltage sag, imbalance in the source voltage and reduce the harmonic content. The active power filter which can be used under the condition of unbalanced or distorted source voltages can compensate the harmonics, reactive and negative sequence components. Simulations have been carried out on MATLAB/Simulink platform with two types of loads. The analysis and simulation results under balanced three phase fault and dynamic load are presented in this paper.