STATIC AND TRACKING STATE ESTIMATION IN POWER SYSTEM USING NEWTON'S METHOD

Abstract

ABSTRACT This paper describes the Newton method for state estimation in electric power systems using the weighted least square approach (WLS). The information matrix that approximates the Hessian matrix in the WLS estimator is updated using the Brown-Dennis technique such that the linear convergence of the WLS algorithm is improved to nearly second order convergence of the Newton method. This proposed method is particularly effective in state estimation of ill-conditioned power systems which encounter difficulties in converging to the solution. The additional computing time for implementing the new algorithm is quite small as the nonzero elements of the Hessian matrix are not re-computed but are extracted from the Jacobian stored in the computer memory. However, there is a slight increase in the storage requirement. Digital computer results are presented for both the static and tracking state.