Real-time online measuring method for dielectric loss factor in insulation life test

Abstract

The invention provides a real-time online measuring method for the dielectric loss factor in an insulation life test. An insulation accelerated aging life test is mainly characterized in that the insulation performance is high while the dielectric loss factor (or power factor) basically keeps constant at an initial value at the 1 / 2 or (2 / 3) stage of the insulation accelerated aging life test; along with the increase of the aging time, the insulation performance degrades gradually while the dielectric loss factor (or power factor) changes at the later stage of the test; and the change rate of the dielectric loss factor further increases at the end of the life. According to the characteristic of the insulation accelerated aging life test, voltage and current signals of a test piece are sampled and measured in real time online at an asynchronous non-integer period; the dielectric loss factor is calculated by an algorithm; and the additional phase offset compensation coefficient of a measuring circuit is obtained by the initial value of the dielectric loss factor and the measured value of the dielectric loss factor when the electrical performance does not degrade at the initial stage of an experiment to perform additional phase offset compensation in order to obtain the accurate measured value of the dielectric loss factor.

Description

technical field [0001] The invention relates to the requirement of on-line measurement of the dielectric loss factor in the insulation aging failure test of electrical equipment and the real-time on-line measurement of the dielectric loss factor during the operation of the electrical equipment, and provides an on-line dielectric loss factor based on time-domain sampling signal The implementation method of the measurement. Background technique [0002] Insulation aging failure of electrical equipment is an extremely important factor affecting the final life and operation safety of electrical equipment. Aging of electrical insulation is an asymptotic random process of the accumulation of various stress damages of its insulation. Usually, the aging failure time is very long when subjected to normal stress in the application process. In the research of new insulation technology and process, in order to evaluate the impact of these new To improve electrical properties, it is nec...

AI Technical Summary

Problems solved by technology

[0003] At present, the methods of dielectric loss factor can be roughly divided into: (1) hardware detection methods, such as traditional Xilin bridge method and zero-crossing comparison method, require high-level hardware design and are sensitive to interference and harmonics, and there are still some problems in measurement. Uncertainty

(2) Based on signal processing methods, such as fast Fourier transform (FFT), time window, etc., to process the sampled signal, but there are problems such as spectrum leakage and fence effect caused by asynchronous sampling and limited sampling data

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