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.