Power Quality Improvement Using Multilevel Inverter Based Shunt Active Filter

Abstract

Harmonics have become a major issue in the recent times due to the high usage of power electronic equipment. Harmonics lead to many problems such as overheating of equipment, interference with the near, by communication lines, high power loss, low power factor and hence poor usage of equipment. Shunt active filters are used to compensate these harmonics and draw only fundamental component of current from the supply. The shunt active filters be designed using multilevel inverters are more efficient when compared to the classical inverters due to their step voltage waveform. In this work, multilevel inverter based shunt active filters are designed using different controllers such PI and fuzzy logic controllers. There is no requirement of a precise mathematical model when fuzzy logic controllers are used for their design unlike the PI controller. A three level H-bridge was used as the inverter for the filter design. The instantaneous active (iLd), reactive(iLq) components of load current are used to produce the reference compensation currents in this Id-Iq control method. Matlab simulation was used to verify the results.