Power quality is one of the major concerns in the present era. It has become important, especially, with the introduction of sophisticated devices, whose performance is very sensitive to the quality of power supply. Power quality problem is an occurrence manifested as a non-standard voltage, current or frequency that results in a failure of end use equipments. One of the major problems is voltage sag which can be solved by custom power devices. One of the more efficient and effective custom power devices is Dynamic voltage Restorer (DVR which is used in distribution networks. It has many advantages like lower cost, smaller size, and its fast dynamic response to the disturbance. This paper presents modelling, analysis and simulation of a Dynamic Voltage Restorer using MATLAB. The analysis was applied for different types of faults without including DVR and including DVR which shows that voltage profile was improved and sag was also mitigated.