A novel linear state tracking approach of power systems

In general, traditional state tracking (ST) methods are formulated and solved by extended Kalman filter (EKF), and their disadvantages are as follows: the first, due to the nonlinearity of power system measurement equations, it is necessary for traditional methods to make linear approximation of power system measuring equations during the solution process, thus the estimation accuracy is affected, especially when the abrupt change occurs between two adjacent measurement snapshots the estimation accuracy obviously decreases; the second, according to the traditional methods during each step of the iteration it is necessary to re-form Jacobian matrix, so the computation efficiency is lower. Since above-mentioned disadvantages affect the application of traditional ST methods, an accurate linearized measurement equation based linear ST method is proposed. The advantages of the proposed method are as follows: in the estimation no linear approximation is needed due to the accurate linearization of the measurement equations, so the estimation accuracy is higher; in the iteration all Jacobian matrices are constant thus the computation efficiency can be improved. Both effectiveness and high efficiency of the proposed method are validated by results of simulation on IEEE benchmark systems. ©, 2015, Power System Technology Press. All right reserved.