High Voltage Mitigation of EHV System by Shunt Reactor vs Shunt Capacitor

摘要

Rajasthan power system has extensively grown in last 10 years due to potential of wind & solar power projects, construction of transmission system for formation of National Grid and for evacuation of large thermal power plants. Large number of 765 kV and 400 kV transmission lines have been constructed. Due to variability of wind and solar power generation, quantum and also direction of power flow on transmission lines is significantly changed. State Load Dispatch Center has instructed to switch off shunt capacitors from 6 pm to 6 am to control high voltage. This paper presents a comparative case study to control high voltage in power system by switching ON shunt reactors vs switching OFF shunt capacitors. Rajasthan power system has four 765 kV GSS, twenty-seven 400 kV GSS, one twenty-two 220 kV GSS and four fifty-two 132 kV GSS is selected to carry out simulation-based case study in MiPower software. Simulation model consists of 943 buses including 85 generator buses, 1142 transmission lines and 201 transformers. The daily routine grid operations without assessing the outcome or achievement level lead to create problems in power network. Shunt reactors are switched OFF at seven 400 kV grid sub stations where as to reduce high voltage shunt capacitor banks have been switched OFF. Case studies are carried out to observe the effect of switching ON shunt reactors to control high voltage instead of switching OFF shunt capacitors. Test network loading is about 10000 MW. The impact on voltage profile of buses, system losses, financial analysis, loadings of system elements is presented at last.