An Iterative Multiarea State Estimation Approach Using Area Slack Bus Adjustment

This paper proposes a new multiarea state estimation (MASE) approach, which estimates the overall system states by utilizing the state estimation (SE) results of the subareas iteratively. In this approach, all the subareas run their SE sequentially in each iteration. The SE results of the boundary buses in a subarea are used as pseudomeasurements for running the SEs of the nearby subareas. An area slack bus angle adjustment approach has been utilized for estimating the bus angles of the overall system with reference to the global slack bus. It has been demonstrated that the use of the subarea SE results, as pseudomeasurements, provides better state estimates for the complete system. The effectiveness of the proposed method has been demonstrated on an IEEE 30-bus system and a 246-bus reduced Northern Regional Power Grid Indian system.