Traditionally, the power system states are estimated with the help of Static State Estimation (SSE) tools, such as Weighted Least Squares (WLS) approach. The SSE is performed using the measurements received from the Remote Terminal Units (RTUs) through Supervisory Control and Data Acquisition (SCADA) system. Generally, for a practical large size system, the SSE takes about 30-60 seconds to complete its execution, whereas the SCADA system scans the measurements from the RTUs typically at the rate of 1-5 seconds. Therefore, the SSE does not consider the updated measurements received from the RTUs during its execution, and its results always fall behind in time with the actual system states. With the advent of the synchrophasor technology, employing Phasor Measurement Units (PMUs), the measurement data reporting rate has increased up to 50 frames per seconds for the 50 Hz system and up to 60 frames per seconds for the 60 Hz system. Hence, there is a need to develop State Estimation (SE) algorithms to provide the state estimates at a relatively faster rate and to ensure the utilization of all the measurements from the RTUs as well as the PMUs. To reduce the total execution time for the SE, a new Multi-Area State Estimation (MASE) approach is discussed in the present talk. In this approach, a power system network is divided into multiple extended sub-areas and the SE is executed for the sub-areas in parallel. The Central Coordinator (CC) consolidates the SE results of the sub-areas by using area slack bus angle adjustment approach. To address the interoperability issues among the SE applications of the sub-areas, due to proprietary nature of the applications and databases, proposed extension of the Common Information Model (CIM) is also discussed. Finally, to test and validate a number of Power System Dynamic State Estimation (PSDSE) algorithms, a new Software-in-the-Loop (SIL) methodology, utilizing the Real Time Digital Simulator (RTDS), is discussed.
Dr. Ankush Sharma is currently working as domain consultant in Smart Grid Center of Excellence (CoE) of Tata Consultancy Services Ltd (TCS). He has close to 15 years of industry experience, primarily in the Energy and Utility domain. He holds Ph.D. and M. Tech. degrees in Electrical Engineering from IIT Kanpur and B. Tech. degree in Electrical Engineering from HBTI Kanpur. He is also a certified Project Management professional (PMP) from Project Management Institute (PMI), USA and holds MBA degree in Finance. He has received various awards in his academic and professional career, including 1st prize for the best student project at Gridtech 2013 in New Delhi, President medal for securing 1st rank in the branch in B. Tech. in 1998, and various appreciations and star of the month awards in TCS. Dr. Sharma is an IEEE member and also a guest faculty member at Indian Institute of Information Technology for Design and Manufacturing (IIITDM), Jabalpur.