Harmonic Partition Traceability Based on Comprehensive K-means Clustering and Longest Common Subsequence Algorithm

With the large-scale access of nonlinear loads in the power grid and the gradual increase of the power electronic rate, the harmonic problem is becoming more and more serious. It is an effective solution to carry out the regional treatment of harmonic pollution in the power system. The harmonic distortion within the same zone is mainly caused by harmonic sources in the zone, and is less affected by other zonal harmonic sources. In this paper, the Discrete Wavelet Transform (DWT) is used to decompose and reconstruct the harmonic data, and a local high-frequency DWT method is proposed to reduce noise and reduce the complexity of subsequent calculations. K-means clustering method is used to partition the harmonics. The Longest Common Subsequence (LCSS) method is applied to solve the time-shift problem in harmonic partitions. The harmonic source is determined according to the different power direction of each sampling point.