State estimation model and algorithm including PMU

Because of the extensive application of phaser measurement unit (PMU) in the power system, traditional power system state estimation has been undergoing an essential change. In this paper, the traditional state estimator is assumed to be functioning normally in the absence of PMU data. Then under given the placement of PMU in the power system, this paper wants to explore the substantial contribution of PMU to power system state estimation. First, it discusses the difference between PMU measurement and SCADA measurement to explain the effect of PMU on traditional power system state estimation. Then, supposing the right value obtained from PMU, it extracts the simpleness of traditional power system state estimation with SCADA data only, and proposes the reduced power system state estimation model which is same as traditional ones. Following, it presents resultant change in handling the problems of the observability, bad data recognition, and estimation accuracy, as well as the solution algorithm of the power system state estimation on line. It is shown that PMU data provides the direct measurement of state which can significantly simplify the traditional state estimator and dose not require any change of the existing state estimator. Simulation result for the IEEE 13 bus system verifies the validity of the study.