Cooperative distributed state estimation: Local observability relaxed

This paper explores a fully distributed state estimation algorithm in multi-area interconnected power systems. By iteratively exchanging information with neighboring control areas, all the balancing authorities (control areas) can achieve an unbiased estimate of the entire interconnection's states. Compared with existing literature on distributed or hierarchical state estimation, the novelty of the proposed approach lies in that: (1) no assumption is needed for all the areas to be locally observable; (2) communication structure can be different than the physical topology of the power network; and (3) no central coordinator is needed for the state estimation in each local control area to achieve provable convergence of the entire system's states with the centralized estimation. The performance of the proposed algorithm is illustrated in the IEEE 14-bus system.