Controlling of Voltage Sag in AC Distribution System by using Fuzzy Logic Controller

Power quality is the major foremost uncertainties in the current scenario. It has become imperative, particularly, with the primer of refined devices, their response to the power supply variations that causes failure of equipment. Major problem discussed here is voltage swell and voltage sag. Dynamic Voltage Restorer (DVR), is the commonly used efficient and operative power device. It is used in transmission and distribution grids. It has several advantages that include quick response time, compact in size, and less cost. It supplies or injects voltage to the power system thereby providing a comprehensive solution to voltage sag. This paper discusses about simulation and modeling of DVR. In this paper Discrete PWM technique and PI controller was used as switching technique.