Gul Hassan Soomro 15MPE06 Supervisor - Dr. Suhail Khokhar creator Department of Electrical Engineering text Nawabshah QUEST 2018 monographic 55p. ABSTRACT Voltage sag disturbance is the most severe and commonly occurring problem in power distribution system . Due to voltage sag nominal supply voltage will be going out of phase to the power consumer's side. Voltage sag disturbance occur due to faults such as single line to ground fault, line to line ground fault and three phases to ground faults which occur in power distribution system. It also occurs due to starting of induction motors and application of heavy loads in power distribution system. Therefore voltage sag power quality problem must be immediately compensated so as to keep electrical components safe from damage. It is done to compensate voltage sag by implementing custom power device such as Dynamic Voltage Restorer. (DVR) is implementing to mitigate voltage sag on critical loads dynamically. The DVR contain sub operating parts such as voltage source converter (VSC), passive filters, energy storage lead acid battery and injection transformer which inject appropriate voltage magnitude to keep balanced load voltage magnitude. The objective of this research is to generate voltage sag disturbance in tested distribution model and implementation of DVR in tested distribution model as to mitigate voltage sag disturbance which is created in distributed tested model. The voltage sag disturbance is created in tested system as to applying faults such as single line to ground fault, double line to ground fault and three phases to ground fault. The experimentaI and simulation results of DVR using MATLAB software ensure the performance of DVR to mitigate voltage sag power quality problem in tested power distribution model. http://tinyurl.com/4959p9zx http://tinyurl.com/4959p9zx