Unit grouping method and device based on time sequence clustering analysis of wavelet transform

Abstract

The invention provides a coherent unit grouping method based on time sequence clustering analysis of wavelet transform, which comprises the following steps: acquiring a power angle swing curve delta deltai(t) of each generator through data acquisition after each generator breaks down and after the fault is removed, and performing Haar wavelet transform on each swing curve for multiple times, obtaining characteristic statistics of the time sequence, and combining the low-frequency trend signals of the time sequence with the statistics to form a characteristic matrix; and normalizing the formed characteristic matrix, and clustering by using a fuzzy c-means clustering method based on particle swarm optimization to realize clustering of coherent units. According to the method, the trend information and the statistical characteristic quantity of the time sequence are utilized in clustering, the effectiveness of coherence clustering is guaranteed, and the method has a good clustering effect and very high calculation efficiency and is suitable for coherence clustering of a large-scale system.

Description

technical field [0001] The invention belongs to the field of dynamic equivalence of power systems, and in particular relates to a unit grouping method and device based on wavelet transform-based time series clustering analysis. Background technique [0002] With the continuous expansion of the scale of the power grid and the development of the power system, the power grid is gradually developing towards the operation of the AC and DC large power grid, which makes the electromagnetic transient analysis of the power system more and more difficult. Reducing the scale of a large system can improve the efficiency of analysis and calculation, and the dynamic equivalent method becomes an effective way to solve this problem. In addition, when the power system is severely disturbed and causes out-of-synchronization oscillation among the fleets, emergency decoupling is required to prevent further expansion of the accident and lead to the collapse of the entire network. occupies an im...

AI Technical Summary

Problems solved by technology

However, the method of identifying the coherent unit by the difference of the swing angle of the generator rotor has problems such as subjectivity and one-sidedness in the process of coherent identification, and does not fully consider the time series characteristics of the power angle swing curve

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