Power Quality Improvement using FUZZY logic Based Dynamic Voltage Restorer (DVR)

Power quality is one of the most important issues to utilities and customers. Power quality problem is abnormal voltage, current or frequency. Distribution networks experience from various types of disturbances like, voltage sag, voltage sewll transients etc., Now the fast developments in power electronics technology have made it possible to mitigate power quality problems. Such as, dynamic voltage restorer can provide the most popular solution to compensate voltage sag/swell by injecting voltage in to the sensitive system. Dynamic voltage restorer is a series connected power electronics based device that can mitigate the power quality problem in the system, by automatically detecting and calculating of injecting power then the inject through an injecting transformer. The proposed system has less number of switching devices and has good compensating capability in comparison with commonly used compensators. Here comes the importance of soft computing techniques like fuzzy logic. With the help of a newly developed fuzzy rule base, the system will be able to correct repeated occurrences of the power quality problems. The modelling and simulation is done using MATLAB/SIMULINK software.