Research On Harmonic State Estimation Based On Wide Area Measurement System

The apearance of wide area system which based on GPS provide a basis for harmonic state estimation. Compared with the SCADA system wide area system increase the measurement of phase angle measurements and maintain time synchronization, which for harmonic state estimation provides a strong condition. In this paper, by research on the situation of harmonic state estimation and the existing method of harmonic state estimation and state estimation with the traditional harmonic basis of comparing selected bus node voltages, bus injection current and Branch current as a measurement, the bus harmonic voltage as state variables, making the harmonic state estimation equations become a linear equation, which greatly simplifies the equation. This provides the rank ordering for the measurement nodes, and in MATLAB environment, respectively, model with modeling and simulation for excluding power transformers and transformer, establishing the harmonic state estimation equation, using least squares method to verify the feasibility of the algorithm. In order to ensure a linear equation, when the system contains a transformer, using the transformer's mathematical model solving transformer harmonic state separately. If the equation of state is sick using the generalized ridge estimate to solution. Generalized Ridge Estimation idea is the add a parameter to the ill diagonal matrix to improve the measurement matrix. Using simulation results to verify the feasibility for both methods the of harmonic state estimation. By analyzing the estimated value and the true value of the error, we can see that the generalized ridge estimate can effectively improve the least squares equation for the lack of pathological demand.