Method for calculating dielectric loss angle of compatible insulating device

Abstract

The invention discloses a method for calculating the dielectric loss angle of a compatible insulating device in the technical field of monitoring. According to the technical scheme, firstly, a Blackman self-convolution window is constructed, current and voltage signals of a device to be detected are collected, and discrete sampling is performed on the current and voltage signals; secondly, windowing truncation is performed on a discrete signal sequence with the constructed Blackman self-convolution window, and a discrete spectrum function of discrete signals after the windowing truncation is obtained; thirdly, the discrete spectrum function of the discrete signals after the windowing truncation is analyzed, and a main lobe width and side lobe characteristics are obtained; finally, voltage and current fundamental wave signal phase angles are solved with the four spectral line interpolation amendment theory, and therefore the dielectric loss angle is solved. According to the method for calculating the dielectric loss angle of the compatible insulating device, the extremely good spectrum leakage restraining effect of the Blackman self-convolution window is used, frequency spectrum correction is performed with the four spectral line interpolation, dielectric loss angle measuring errors based on the FFT theory under asynchronous sampling are avoided, the measuring precision is high, and requirements for hardware are low.

Description

technical field

[0001] The invention belongs to the technical field of monitoring, in particular to a method for calculating the dielectric loss angle of capacitive insulation equipment. Background technique

[0002] Classified by insulation structure, equipment with capacitive insulation structure accounts for the vast majority of high-voltage power equipment. The dielectric loss angle δ (referred to as the dielectric loss angle) is an important parameter to measure the insulation performance of electrical equipment, and it can accurately reflect the overall performance of the insulation. Accurate monitoring of the dielectric loss angle can provide a reliable basis for fault diagnosis of electrical equipment and an important guarantee for the safe and stable operation of the power system.

[0003] Under normal circumstances, the dielectric loss angle is a very small value, about 0.001~0.02rad. In actual measurement, because the true value is too small, it is often easily o...

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