A Relative Comparison Method Combined with Correlation Analysis and Filtering

Abstract

The invention discloses a relative comparison method which is high in anti-jamming capability and measuring accuracy, wide in application range and used for measuring relative dielectric loss (delta tan delta) of a capacitive apparatus. Before the delta tan delta of the capacitive apparatus is measured by means of the relative comparison method, firstly, filtering performance of a correlation function is fully utilized, leakage current of two selected apparatuses is correlated to standard fundamental waves respectively, the leakage current is subjected to filtering processing, then relative dielectric loss of the apparatuses is obtained by means of time delay feature of a cross-correlation function, and thereby, an algorithm is quite accurate. The relative comparison method in combination with correlation analysis filtering performance has the advantages that the anti-jamming capability and measuring accuracy are high, the application range is wide, and certain practical application value is achieved.

Description

technical field [0001] The invention relates to a measurement algorithm applied to on-line monitoring of dielectric loss of high-voltage capacitive equipment, and belongs to the technical field of on-line monitoring of high-voltage capacitive equipment. Background technique [0002] Capacitive devices (current transformers, coupling capacitors, capacitive voltage transformers and high-voltage bushings, etc.) account for a considerable proportion of power system equipment, and the safety and reliability of these devices is the basis for the operation of the entire power system. A large part of electrical equipment (especially high-voltage equipment) damage accidents is caused by insulation damage, and by measuring dielectric loss (tanδ, hereinafter referred to as dielectric loss) or relative dielectric loss, it can be found that the integrity of the electrical equipment insulation system is in the early development stage Defects or large concentrated local defects. Therefore...

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Problems solved by technology

[0006]However, the dielectric loss of capacitive equipment is a small value under normal conditions, so the interference of the system itself (harmonic interference) and external interference (environmental interference) have great influence on traditional The measurement method for obtaining relative dielectric loss will have a great impact, so the traditional relative comparison method will no longer be accurate in some cases (such as when harmonic interference or environmental interference is large)

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