Author : Ali Jumah Ahmed and A.K.Bhardwaj

Power quality is a very important issue due to its impact on electricity suppliers, equipment manufactures and customers. Power quality is described as the variation of voltage, current and frequency in a power system. It refers to a wide variety of electromagnetic phenomena that characterize the voltage and current at a given time and at a given location in the power system. A Voltage Sag is a momentary decrease in the root mean square (RMS) voltage between 0.1 to 0.9 per unit, with a duration ranging from half cycle up to 1 min. It is considered as the most serious problem of power quality. It is caused by faults in the power system or by the starting of large induction motor The problem of voltage sags and its severe impact on sensitive loads is well known. To solve this problem, The DVR is a modern and important custom power device for compensation voltage sags in power distribution systems. The Dynamic Voltage Restorer (DVR) is fast, flexible and efficient solution to voltage sag problem. The DVR is a series compensator used to mitigate voltage sags and to restore load voltage to its rated value. The main focus behind this paper is to analyse the downstream fault current problem and reduce the impact of noise and voltage sag in distribution system.

Keywords: Voltage Sag, Dynamic Voltage Restorer (DVR, fault current interruption, Power quality.

Article published in International Journal of Current Engineering and Technology, Vol.5, No.1 (Feb-2015)