Power System Harmonic Analysis Using State-Estimation Method for Japanese Field Data

The harmonic state-estimation (HSE) method appears to be effective but its applicability has yet been fully verified using actual data in power systems. Particularly in Japan, there has been no verification of the applicability of the method in actual power systems. In this paper, for Japanese field data synchronized with a Global Positioning System (GPS) clock, a practical method for power system harmonic analysis is proposed, which is based on HSE. In the proposed method, in order to improve the precision of HSE, uncertain parameters R, X, and Y of the transmission lines are determined from measured fundamental data, and bad measured harmonic data excluded systematically. It is also possible to estimate the error of each measurement instrument by using HSE. It is confirmed that by using only partial and selected measurement data synchronized with a GPS clock, the entire harmonic distribution of the actual power system has been obtained effectively. In this paper, field-test results of the HSE on an actual Japanese power system are shown. Furthermore, an example of harmonic analysis based on HSE in the actual power system is presented, which is prediction of harmonic voltage distribution after a change of the actual power system configuration.