P-Q theory based Shunt Active Power Filter for power quality under ideal and non-ideal grid voltage conditions

Power quality deterioration due to the increased use of power electronic switching devices has become a major problem faced by electrical engineers. Various power conditioning devices such as FACTS devices are developed for power quality improvement. Among them Shunt Active Power Filter (SAPF) is used for harmonic current compensation. SAPF supplies the reactive power required by the nonlinear load and maintains the power quality at source side. Performance of SAPF is at its best during ideal grid voltages. When the grid voltage is distorted with harmonics the THD reduction using SAPF is poor. In this paper performance of a p-q theory based SAPF is analyzed. Then a new improved control with p-q theory is used to improve the performance of SAPF during non ideal grid voltage conditions and the results are compared.