Abstract
Effective state estimation is critical to the security operation of power systems. With the rapid expansion of interconnected power grids, there are limitations of conventional centralized state estimation methods in terms of heavy and unbalanced communication and computation burdens for the control center. To address these limitations, this paper presents a multi-area state estimation model and afterwards proposes a consensus theory based distributed state estimation solution method. Firstly, considering the nonlinearity of state estimation, the original power system is divided into several non-overlapped subsystems. Correspondingly, the Lagrange multiplier method is adopted to decouple the state estimation equations into a multi-area state estimation model. Secondly, a fully distributed state estimation method based on the consensus algorithm is designed to solve the proposed model. The solution method does not need a centralized coordination system operator, but only requires a simple communication network for exchanging the limited data of boundary state variables and consensus variables among adjacent regions, thus it is quite flexible in terms of communication and computation for state estimation. In the end, the proposed method is tested by the IEEE 14-bus system and the IEEE 118-bus system, and the simulation results verify that the proposed multi-area state estimation model and the distributed solution method are effective for the state estimation of multi-area interconnected power systems.
Highlights
Power system state estimation has an important impact on power system security assessment and on-line security control
Each sub-system independently conducts the individual state estimation according to the local measurements, and only limited information of consensus variables and boundary-bus state variables is shared among adjacent regions, while the system-level global optimal solution can be obtained within several iterations
(2) The proposed distributed state estimation method does not need a coordination center, but only requires a simple communication network for exchanging limited data of boundary state variables and consensus variables among adjacent regions, it is quite flexible in terms of communication and computation for state estimation
Summary
Power system state estimation has an important impact on power system security assessment and on-line security control. Authors of [10] proposed a multi-area paralleled state estimation method on the basis of sub-regions independently performing the local state estimation and the control center coordinately calculating the global optimal solution with the boundary variables. This paper proposes a nonlinear multi-area state estimation model and presents a consensus theory based distributed state estimation method. Each sub-system independently conducts the individual state estimation according to the local measurements, and only limited information of consensus variables and boundary-bus state variables is shared among adjacent regions, while the system-level global optimal solution can be obtained within several iterations. (1) A multi-area state estimation nonlinear model is proposed in this paper by using Lagrange multiplier function, and a consensus theory based distributed state estimation method is designed to solve the model.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
