Frequency domain test and analysis system and method for cable overall ageing life evaluation

Abstract

The invention belongs to the technical field of cable nondestructive test and life evaluation and specifically relates to frequency domain test and analysis system and method for cable overall ageing life evaluation. A data acquisition module collects voltage and current response of a cable under actions of AC signals in different frequencies, and calculates cable complex capacitance spectrum and dielectric spectrum; according to temperature signals measured by a temperature probe, the dielectric spectrum calculated based on the test data is subjected to temperature correction treatment by calling temperature compensation factor of the cable in such material stored in the system to obtain a corrected frequency domain curve under a reference temperature; and an SH factor calculation and life evaluation system calculates an SH factor value for reflecting a current state of the cable according to the corrected dielectric spectrum curve, and extrapolates residual life of the cable under the current service condition and a current EAB (elongation at break ) value according to curve information recorded in the system. The system can realize in-service inspection and life evaluation of the on-site in-service cable.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing and life evaluation of cables, and in particular relates to a frequency domain test analysis system and method for evaluating the overall aging life of cables. Background technique [0002] In nuclear power plants and other industrial production fields, cables, as key electrical components, undertake the functions of power transmission and signal transmission. The long-term current-carrying heating of the core conductor in the cable and the influence of external environmental factors will cause the insulation material of the cable to age or even fail, resulting in interruption of power or measurement and control signals, affecting the safe and reliable operation of the system; Fires seriously threaten industrial production and people's living safety. Therefore, using state monitoring methods and analysis methods, in-depth research on the characterization parameters that can reflec...

AI Technical Summary

Problems solved by technology

Among them, the elongation at break test in the mechanical test is sensitive to the aging process of the cable insulation and can be used to reflect the overall aging state of the cable. However, since this technique is a destructive test, it is necessary to disassemble the service cable and perform the test in the laboratory. In the overall aging life evaluation of actual cables, there are great limitations; for electrical testing methods, although most of them are non-destructive testing techniques, since the irreversible aging of cable insulation is mainly caused by thermal oxidation, the aging effect is usually reflected in the mechanical properties. During the degradation, the insulation resistance and power frequency dielectric loss of the cable cannot be directly used for the life evaluation of the cable

So far, there has not been a set of on-site non-destructive testing technology and testing equipment that can be used for the overall aging life evaluation of cables in the industry

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