Design and performance analysis of a shunt active filter for power quality improvement

Abstract

In recent years, power engineers and consumers have been focusing on the quality of power. Until two decades ago, the majority of the loads used by the consumers were passive and linear in nature and hence had less impact on the power system. The technical advancement in the semiconductor devices such as Switched Mode Power Supply (SMPS), rectifier, chopper etc. certainly good. Nevertheless, excessive use of power electronic devices has resulted in the generation of current harmonics and reactive power issues in the power system network. Because of the non-linear loads, the purity of the supply waveform is lost. Consequently, many power quality problems such as voltage sag, swell, flickers, harmonics, etc. arise.Apart from non-linear loads, some system events such as capacitor switching, motor starting and abnormal faults may also cause power quality problems. Among the power quality problems, harmonics seem to be a major factor contributing to the pollution of the power system. They are capable of causing problems such as transformer overheating, voltage degradation, rotary machine vibration, damaging of electric power components and malfunctioning of medical facilities etc. As has already been said, the power distribution system is polluted by harmonics and the reactive power newlinedisturbances due to the large usage of non-linear loads (computers, laser printers, MPS, rectifier etc.), which are undesirable. It is a gigantic challenge to deal with and eliminate the undesirable current harmonics and compensate for the reactive power of the power system. newline newline