System harmonic impedance estimation method based on LOF screening-heuristic segmentation algorithm

• Main Authors: NIU HAOMING, FENG WENTAO, LIU WEI, MIAO HONG, YANG YONG, WANG YONGNIAN, QI YING, CUI LIXIN, YANG RUI, ZHAO JINGUO, KIM YOUNG-SUNG, HE XIN, CHEN SHIBIN, LI WENTAO, XIE YINGZHOU, LIU WENFEI, HAO RUHAI, ZHANG XUJUN, HAN KAILI, NIU ZHEN
• Format: Patent
• Language: Chinese; English
• Published: 01.03.2024
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

According to the system harmonic impedance estimation method based on the LOF screening-heuristic segmentation algorithm, firstly, Pearson correlation coefficients are used for screening to obtain data with high correlation between harmonic voltage and current amplitude, and then an LOF method is used for eliminating abnormal values in the data, so that the influence of background harmonic fluctuation and the abnormal values on an impedance estimation result is reduced; then, a heuristic segmentation algorithm is used for checking a system harmonic impedance abrupt change point, real-time estimation of harmonic impedance is achieved, and calculation errors are reduced; and finally, the harmonic impedance of the system is calculated by using a complex field robust regression method, so that an error caused by separate calculation of a real part and an imaginary part of a harmonic data vector in a traditional robust regression method can be effectively eliminated. Simulation and experiment results show effectiv