Optimum Tap Position of 400 Kv Transformer in Rajasthan Power System

This paper presents a case study to control high voltage in power systembychanging tap position of 400/220 kV transformers. Rajasthan power system having four765 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 continuous grid operations without operational studies and supervision may lead to create problems in power network. Similar problem is raised up in Rajasthan power network the taps of 400/220 kV transformers of 400 kV grid substation is lower than nominal while at some it is higher than nominal. Due to lack of observation thirteen numbers of 400 kV grid sub stations are observed to use higher tap ratios than nominal which results in higher network voltage at 220 kV level. Even the operators reversing the situation by keeping system shunt capacitors off to reduce the high voltage condition. Test network loading is about10500 MW. Case studies are carried out to observe the effect of reduction in transformer tap position of 400/220 kV, over the thirteen 400 kV grid substations. The impact on voltage profile of busses, system losses, financial analysis, loadings of system elements are presented at last.