A new state estimation method with bad data rejection properties

A new power system state estimation method with bad data rejection properties is proposed. The method uses a new objective function which a window-likelihood function is used to evaluate each measurement´s influence and rejection of failed measurements or measurements whose absolute value of measure error is beyond error limits is a consequences of the objective function form. Power flow equation and zero injection of link bus are considered as constraints in order to improve correctness of state estimation. Mathematical model of the optimization problem is built based on both the new objective function and constraints, and modern inner point algorithm is used to solve the problem. The reason of good performance of bad data rejection of the method is analyzed. The proposed method does not need to perform additional observability analyze, bad data detection, or subjective weighting factors setting, thus substantial reduction in maintenance efforts can be achieved. Numerical simulations are cared out using 4 bus test system, 30, 118 bus test models and a practical utility system. Test results of test system verify that the proposed method has good performance of bad data rejection and archives high good measurement rate in practical system.