Power System Linear State Estimation Based on Phasor Measurement

This paper analyzes the measuring errors of the phasor measurement unit (PMU) and points out the necessity of state estimation based on PMU measurement. A linear measurement equation and linear static state estimation algorithm based on right-angle coordinates are given when PMU measurements only are used. Based on the improvement of the system state estimation method by using load forecasting and load flow, through the deduction and simplification of the error covariance equation, a new predictive error covariance equation is proposed. By combining the proposed error covariance equation with the linear measurement equation, a new linear dynamic state estimation algorithm is also proposed. The application conditions of linear state estimation are discussed and the effectiveness of the proposed algorithm is illustrated with numerical simulation using an IEEE 30-bus system.