Performance Analysis of Reactive Power Circulation Control on Extra High Voltage Transmission System Parameters

In this research paper, a real time case study on Jaipur city Extra High Voltage (EHV) system for reactive power circulation is presented. Jaipur's EHV system, consisting of 20 buses, 18 transmission lines, 10 power transformers, 6 load buses, and 2 shunt reactors, has been modelled in MATLAB Simulink. Hourly recorded system parameters are collected from the grid substations for simulation studies. A methodology is proposed based on coordinated changes of tap positions of power transformers for circulating reactive power control in EHV transmission systems. As per simulation studies, average reactive power circulation is reduced to 5.6 MVAR, reactive power circulation is reduced by 87%, network voltage at 220 kV and 132 kV voltage levels is improved, and voltage variation index is decreased, transmission losses are reduced by 0.0618%, reactive power loss is reduced by 2.23%. Proposed methodology reduces reactive power and apparent power flow on lines and transformers considerably as compared to the base case. An annual energy savings of 20.76 lac is envisaged, which corresponds to an annual cost savings of Rs 1.03 crore in the Jaipur EHV transmission system with the application of the proposed methodology.