Mitigation of Voltage Quality Problem using Adaptive Fuzzy-PI Controlled Ultra-Capacitor based Dynamic Voltage Restorer(DVR) :- Case study on Desta Garment PLC. Butajira

Abstract

Nowadays, a voltage quality problem has become a major issue to deal with to main tain quality supply. Similarly, in Ethiopia, due to the developments of modern in dustries and the application of modern control systems, voltage quality problems becomes very critical. It will result in damage or malfunction of industrial equip ment which will result in high economic losses. Thus, such power problems should be mitigated through the implementation of fast emerging electronic technology to protect the industrial equipment from the consequences of voltage quality problems. In this thesis, voltage quality problems and their mitigation technique in Desta Plc. have been studied. Due to faults on a nearby substation, voltage sag and swell occurs at the terminals to which power is supplied to the factory. Therefore, the factory has been faced with a partial shutdown for hours or even for days until the problem is cleared, reducing the life span and efficiency of electrical devices, and product deliv ery delay. To address those consequences of voltage quality problems, Adaptive Fuzzy-PI Con trolled Ultra-Capacitor-based Dynamic Voltage Restorer (DVR) which is more attrac tive, has low losses, higher energy capacity, and is cost-effective among the custom devices is selected and developed in this thesis. The input data collected from the factory used to simulate the system in MatLab/Simulink environment with and with out the proposed mitigating technique and results are compared to IEEE 1250-1995 and National Equipment Manufacturers Association (NEMA) standards. The simulation results indicate that the suggested controller is powerful and gives a considerably significant improvement in voltage sag and swell conditions satisfying both IEEE 1250-1995 voltage magnitude of 1.0 pu and IEEE 519-1992 acceptable harmonic content standards of magnitude less than 5%.