Power System State Estimation Based On WAMS And Its Application

With the development of modern power network, the operation mode and structure of power system becomes more and more complicated. As a core function of EMS (Energy Management System, EMS), the precision and real-time property of state estimation will directly effect the accuracy of analysis, decision and control in power system. Thus, to ensure the safety, efficiency and reliabilty of power system, it is highly important to capture the real-time operation state in Electric Control Center accuratelly, which puts forward higher requirements on the research and application on state estimation theory.Firstly, the necessity and significance of research on state estimation is briefly introduced. The research status and direction on state estimation have been widely reviewed. Although research on synchronized phasor measurements technology based WAMS (Wide Area Measurement System, WAMS) can indeed in some degree relieve the dynamic analysis and control problem in majority of internet power system, it is shown that the WAMS and EMS will be complementary developed within a long period.Secondly, the theory of state estimation is detailly introduced, including basic concept, main functions, procedures, typical mathematical model and traditional algrithms. According to the application of state estimation theory in WAMS, the principle of WAMS structure is given. And then, the state estimation of power system based on WAMS data is introduced. To improve the system redundancy and accuracy, a new mixed measurement method is introduced by integrating the data of PMU(Phasor measurements unit, PMU, a core component of WAMS) and SCADA (Supervisory Control And Data Acquisition, SCADA). Based on the mixed mesurement method, the measurements accuracy is improved, which is mainly focus on the real functions of state estimation and optimal state observable algrithm in PMU.Finally, the result of state estimation is analyze and evaluated using comprehensive analysis method. It is shown that the economic and social benefits of electric operation has been improved significantly.