Power system state estimation enhancements

The objective of this dissertation was to develop several enhancements to the existing state estimators. The methods proposed in the dissertation complement the deficiencies of the present state estimation schemes.; Chapter III presents a three phase power system state estimator, which produces an estimate of the actual three phase network status in the presence of all possible imbalances. The detailed system models and formulations of the three phase state estimator are given along with the inclusion of the line current magnitude data into the conventional measurement set. The simulations are carried out for several test systems with various measurement sets, and the corresponding results are presented.; The fourth chapter presents a method for detection and identification of topology errors in electric power systems. A two stage LAV state estimator identifies the circuit breaker status by estimating the power flows through the circuit breakers, which are modeled as zero impedance branches. The proposed state estimation scheme detects and identifies the split bus as well as the branch outage even under existing bad analog measurements.; Chapter V addresses the issues of the external system modeling and the detection of topology errors in the external system. The buffer system, which is modeled in detail in the external system model, is identified by sensitivity analyses such as measurement sensitivity and branch sensitivity. Topology errors in the external system are detected by examining the colinearity of the normalized residual vector and the columns of the normalized residual to branch sensitivity matrix. The colinearity is simply tested via a "cosine test." Several topology error cases in the external system are simulated, and the results are presented. Detectability and identifiability of topology errors are discussed.; A summary of the entire research along with some concluding remarks is included in chapter VI. This chapter also gives suggestions on the future work yet to be done to extend the results of this dissertation.