Research On Weighted L₁Norm State Estimation For County Power Grid Using CIM

State Estimation is the major component of the Energy Management System (EMS), it provides complete and reliable data for the other application software of EMS, but in the county power grid, the rate of state estimation is still low. In addition, in order to achieve its own need,county power grid uses lots of system from different manufacturers, because the standard is not unified, it causes the problems that the data exchange, information sharing, interoperability from these systems, the standard IEC-61970can effectively solve these problems, the standard establishes the Common Information Model (CIM).Therefore, the research on state estimation for county power grid using CIM meets the development trend of modern county power grid.First, this paper introduces the research survey of CIM and gives an overview of the international trend of power system state estimation, followed by a statement of the basic concepts of CIM and how to build a power system database in the platform based on CIM according to the relationship between the three types of CIM, then using VC++and Qt, reading CIM.database, on the basis of the relationship between terminal, connectivitynode, and the conductingequipment, achieving the topology analysis of power grid by the breadth-first search, at the same time, accomplishing the calculation of the grid element parameters, realizing the interface by using the Ui of Qt Designer and the signal slots mechanism of Qt. at last, by the model of a county power grid substation in Guangxi to verify the feasibility of the topology analysis program,which proves model and parameters for the calculation of state estimation.Against the traditional weighted least square (WLS) is sensitive to the bad data, it is easy to make the estimation results have deviation, so state estimation model uses weighted L1norm state estimation, using Matlab programming, realizing state estimation by using primal-dual interior point method based on perturbation KKT, the results for the IEEE-14、IEEE-30、IEEE-118bus system show that the weighted L1norm estimation can effectively resist the bad data, estimated effect is good, at the same time, the algorithm still shows good computation performance, fast calculation, good convergence, the iteration number is not increasing rapidly with system expanded.At last, the procedure is applied to the example of a county power grid substation in Guangxi, it has fast calculation, and gets reasonable estimate of the results although the system has bad data, which provides a certain reference value for the development of state estimation of county power grid.