Method for obtaining interval parameters of typical working conditions of harmonic users

Abstract

The invention relates to a method for obtaining interval parameters of typical working conditions of harmonic users. The method comprises the following steps of obtaining maximum values and minimum values of a plurality of monitoring time segments of any phase in harmonic detection data of users to form an interval data sample set; performing interval principal component analysis on the interval data sample set by adopting CPCA, and selecting a sample characteristic quantity according to a variance contribution rate; calculating the similarity between data points for the sample characteristic quantity, and defining input parameters to perform affinity propagation clustering until an algorithm is subjected to iterative convergence; calculating deviation degree indexes of interval sample points of the sample characteristic quantity, and when the deviation degree indexes are smaller than a set threshold, defining the deviation degree indexes as transitional working conditions and removing the sample characteristic quantity and corresponding original data; outputting an original sample set according to a working condition division result which does not contain the transitional working conditions; and calculating typical parameters of harmonics of the working conditions. According to the method, the harmonic pollution level of an electric network after user access and running can be assessed more reasonably, thereby facilitating analysis and control on the harmonic users.

Description

technical field [0001] The invention relates to a method for acquiring interval parameters of a typical working condition of a harmonic user. Background technique [0002] In recent years, with the grid-connected operation of a large number of impact loads and distributed power sources, the harmonic pollution in the power system has become more and more serious. The existence of harmonics will cause additional loss and heat generation of electrical equipment, reduce the working accuracy and reliability of relay protection, control and detection devices, and may even cause parallel or series resonance, which will damage electrical equipment. Therefore, comprehensive treatment of harmonics is imminent . [0003] Establishing a harmonic source model can analyze and control the harmonics existing in the power grid. In the actual power system, there is a coupling effect between different harmonic voltages and harmonic currents, that is, the harmonic currents can be expressed by...

AI Technical Summary

Problems solved by technology

[0004] A large amount of historical monitoring data is conducive to harmonic user modeling, but the data recorded by power quality monitoring are mostly four types of statistical indicators within a monitoring period, namely the maximum value, minimum value, average value and 95% probability value indicators, harmonic There is often no time-corresponding relationship between voltage and current in the same monitoring period, so a direct physical connection cannot be established

Moreover, the four types of statistical indicators in the existing monitoring system essentially use definite values ​​to represent the uncertain harmonic information within a certain detection period

Images