SIMULATION AND MITIGATION OF POWER QUALITY DISTURBANCES ON A DISTRIBUTION SYSTEM USING DVR

• Main Author: CHANDRASEKARAN, CHANDRASEKARAN
• Format: Final Year Project
• Language: English
• Published: universiti teknologi petronas 2005
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://utpedia.utp.edu.my/7915/1/2005%20-%20SIMULATION%20AND%20MITIGATION%20OF%20POWER%20QUALITY%20DISTURBANCES%20ON%20A%20DISTRIBUTION%20SYSTEM%20USING%20DVR.pdf; http://utpedia.utp.edu.my/7915/
• Institution: Universiti Teknologi Petronas

Voltage sag is the most important power quality problem faced by many industrial customers. Equipment such as process controllers, programmable logic controllers, adjustable speed drives, robotics, etc used in modern industrial plants are actually becoming more sensitive to voltage sags. Voltage sags are normally described by the magnitude variation and duration, and also characterized by unbalance, non-sinusoidal wave shape and phase angle shift. One of the most common mitigation solution is installing uninterrupted power supply (UPS). To meet the demand for more efficient mitigation solution, the Dynamic Voltage Restorer (DVR) will be deployed. When a fault occurs, either at the high voltage source end or at the consumer end, the DVR injects active and reactive power for the restoration of the voltage sags in the network. This thesis presents the power quality problems faced by the power distribution systems in general and then concentrates on analyzing an important and specific distribution system in particular. A dynamic voltage restorer (DVR) is connected on the 11KV of an utility feeder to Ipoh hospital, in reducing the voltage sags, that affect the operation of sensitive loads to the hospital. Case studies were conducted at four industrial sites (Hitachi plant and Nihoncanpack at Bemban, Filrex at Bercham and Ipoh Hospital) by monitoring and taking physical sag measurements for a period of one month. The real time measurements were carried out to identify the types power quality disturbances that exits in the various plants before providing the custom power device as a mitigation tool. The Ipoh Hospital is taken for a special case study since the hospital has to maintain high quality power supply to the medical equipments such as CT Scan, Magnetic Resonance Imaging (MRI), Magnetic Scanner, X-ray unit, and other life savingequipment. For simulation study, PSS/ADEPT and PSCAD/EMTDC software packages were used in modeling of the power distribution system. With the PSS/ADEPT simulation tool, the voltage severity is studied by introducing different types of faults. The PSCAD/EMTDC is a graphical user interface simulation tool to simulate sag waveforms for various types of faults. A DVR was modeled using the PSCAD/EMTDC software and simulated for voltage sag mitigation. The recorded waveform shows the DVR as a potential custom power solution provider. The DVR can improve the overall voltage regulation. The results obtained from the DVR show that the voltage sags are reduced by bringing the supply voltage level to 100%. The simulated results were verified for selected faults theoretically. vn