State estimation at all India level

Indian power system is one of the largest synchronously operated Power System Networks in the world. It has an installed capacity of about 303 GW. Indian power system has complex transmission network along with many cross border connections. It is monitored by a multi-level integrated Supervisory Control & Data Acquisition (SCADA)/ Energy Management System (EMS) installed at many control centres dispersed all over India. SCADA/EMS of National control centre is integrated with SCADA/EMS systems of five Regional control centres. SCADA/EMS systems of Regional control centres in turn are integrated with SCADA/EMS systems of 32 State control centres. It is important to use all real-time tools to help the operator in maintaining the grid in a highly secure and reliable manner. Successful implementation of State Estimator is said to be critical requirement for efficient EMS. An exercise was taken up by Power System Operation Corporation Limited (POSOCO) with an objective of improving the usage of State Estimation in Load Despatch Centres in India. In this process, it has been interacting with experts both in India and abroad with the objective of learning and making continuous improvement. Successful running of State Estimation at All India level involves maintaining and tuning of a large SCADA and Network database. Such a big database needs correction in topology, device parameters, connectivity model, etc. This paper focusses on all such related issues, its solution and impact on State Estimator output.