Power quality issues and its mitigation techniques

Abstract

The electrical energy is one of the easily used forms of energy. It can be easily converted to other forms of energy. With the advancement of technology, the dependency on the electrical energy has been increased greatly. Computer and telecommunication networks, railway network banking, post office, life support system are few application that just cannot function without electricity. At the same time these applications demand qualitative energy. However, the quality of power supplied is affected by various internal and external factors of the power system. The presence of harmonics, voltage and frequency variations deteriorate the performance of the system. In this project the frequently occurring power quality problem- voltage variation is discussed. The voltage sag/dip is the most frequently occurring problem. There are many methods to overcome this problem. Among them the use of FACT devices is an efficient one. This project presents an overview of the FACT devices like- DVR, D-STATCOM, and Auto-Transformer in mitigating voltage sag. Each one of the above device is studied and analysed . And also the control strategies to control these devices are presented in this project. The proposed control strategies are simulated in MATLAB SIMULINK environment and the results are presented. A comparative study based on the performance of these devices in mitigating voltage sag is also presented.