CN-121978173-A - Electrified detection method for defects of cable grounding system

CN121978173ACN 121978173 ACN121978173 ACN 121978173ACN-121978173-A

Abstract

The invention relates to the technical field of cable detection and discloses a method for detecting the defect electrification of a cable grounding system, which comprises the steps of injecting a low-frequency detection current signal into the cable grounding system and synchronously collecting a response voltage signal; the method comprises the steps of obtaining an equivalent pure resistance value through frequency domain decomposition and complex deconstruction, combining voltage signal waveform characterization to obtain multidimensional signal characteristics, carrying out pattern matching on the multidimensional signal characteristics based on typical physical defect types of a cable grounding system to obtain a characteristic defect mapping table, constructing a fault characteristic database according to the characteristic defect mapping table, carrying out search comparison on multidimensional signal characteristic vectors detected on site and the fault characteristic database, carrying out intelligent diagnosis on comparison results based on a mixed expert network to obtain specific defect types and severity of the cable grounding system, carrying out situation research and judgment on the specific defect types and severity to obtain early warning information, and improving the defect live detection efficiency of the cable grounding system.

Inventors

ZHOU LI
Chai Jiahui
LIU XIN
NI CONG
NI XIAOLU
YAN LINGZHU
TAN JIANHUA
LI CHENGJI
ZHAO MINGYANG
WANG CHAO

Assignees

杭州巨骐信息科技股份有限公司
杭州溢光量芯传感技术有限公司
浙江富盛智能装备有限公司
杭州正益新能源科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A method for live detection of defects in a cable grounding system, the method comprising: s1, injecting a low-frequency detection current signal into a cable grounding system, and synchronously collecting a response voltage signal generated by the low-frequency detection current signal in the cable grounding system; S2, carrying out frequency domain decomposition on the response voltage signal and the low-frequency detection current signal to obtain loop impedance of the cable grounding system, and carrying out complex deconstruction on the loop impedance to obtain an equivalent pure resistance value of the loop impedance; S3, carrying out state characterization on the equivalent pure resistance value and the waveform of the response voltage signal to obtain a multidimensional signal characteristic of the cable grounding system; S4, performing pattern matching on the multidimensional signal characteristics based on typical physical defect types of the cable grounding system to obtain a characteristic defect mapping table of the cable grounding system, and constructing a fault characteristic database of the cable grounding system according to the characteristic defect mapping table; s5, searching and comparing the multi-dimensional signal feature vector detected on site with the fault feature database, and performing intelligent diagnosis on the comparison result based on a hybrid expert network to obtain the specific defect type and severity of the cable grounding system; s6, situation research and judgment are carried out on the specific defect type and the severity degree, and early warning information of the cable grounding system is obtained.
2. The method for detecting the defect electrification of a cable grounding system according to claim 1, wherein the step of injecting a low-frequency detection current signal into the cable grounding system and synchronously collecting a response voltage signal generated by the low-frequency detection current signal in the cable grounding system comprises the steps of: Inputting a low-frequency detection current signal to a grounding down wire of a cable grounding system; receiving an induced current of a loop in the ground down conductor; And collecting the voltage generated by the induced current on the cable grounding system to obtain a response voltage signal of the cable grounding system.
3. The method for detecting the defect electrification of the cable grounding system according to claim 1, wherein the frequency-domain decomposition of the response voltage signal and the low-frequency detection current signal is performed to obtain a loop impedance of the cable grounding system, and the complex deconstruction is performed on the loop impedance to obtain an equivalent pure resistance value of the loop impedance, and the method comprises the steps of: Filtering and extracting the response voltage signal and the low-frequency detection current signal to obtain a target frequency voltage signal and a current signal of the cable grounding system; Performing frequency domain transformation on the target frequency voltage signal and the current signal to obtain fundamental wave voltage phasors and fundamental wave current phasors of the cable grounding system; Carrying out complex quotient operation on the fundamental voltage phasor and the fundamental current phasor to obtain loop impedance of the cable grounding system; and (3) carrying out resistance component separation on the loop impedance to obtain an equivalent pure resistance value of the loop impedance.
4. The method for detecting the defect electrification of the cable grounding system according to claim 1, wherein the step of performing state characterization on the equivalent pure resistance value and the waveform of the response voltage signal to obtain the multidimensional signal characteristic of the cable grounding system comprises the following steps: performing time domain statistical analysis on the equivalent pure resistance value to obtain the resistance statistical characteristic of the cable grounding system; extracting the amplitude proportional relation and distortion degree of harmonic components in the response voltage signals to generate harmonic distortion characteristics of the cable grounding system; carrying out noise power spectrum analysis on the waveform of the response voltage signal to obtain the noise energy characteristic of the cable grounding system; carrying out chaotic characteristic identification on the time sequence of the response voltage signal to obtain nonlinear dynamics characteristics of the cable grounding system; and integrating the resistance statistical characteristic, the harmonic distortion characteristic, the noise energy characteristic and the nonlinear dynamics characteristic into a multidimensional signal characteristic of the cable grounding system.
5. The method for detecting the defect electrification of the cable grounding system according to claim 4, wherein the step of identifying the chaotic characteristic of the time sequence of the response voltage signal to obtain the nonlinear dynamics characteristic of the cable grounding system comprises the following steps: carrying out state space reconstruction on the time sequence of the response voltage signal to obtain a reconstructed phase space track of the cable grounding system; performing information entropy extraction on the reconstructed phase space track to obtain entropy value characteristics of the response voltage signal; carrying out association dimension analysis on the reconstructed phase space track to obtain dimension characteristics of the cable grounding system; And carrying out multidimensional feature aggregation on the entropy feature and the dimension feature to obtain the nonlinear dynamic feature of the cable grounding system.
6. The method for detecting the defects of the cable grounding system in the live line mode according to claim 1, wherein the step of performing pattern matching on the multidimensional signal characteristics based on typical physical defect types of the cable grounding system to obtain a characteristic defect mapping table of the cable grounding system, and constructing a fault characteristic database of the cable grounding system according to the characteristic defect mapping table comprises the following steps: Obtaining a cable grounding system sample corresponding to a typical physical defect type in the cable grounding system; Performing supervised feature mapping on the cable grounding system sample to establish an association between the multi-dimensional signal features and the typical physical defect types; Performing pattern mining on the multidimensional signal characteristics based on the association relation to obtain a core characteristic expression pattern of the typical physical defect type; Rule induction is carried out on prestored fault mechanism field knowledge and the core feature expression mode, so that a feature defect mapping table of the cable grounding system is obtained; based on the characteristic defect mapping table, carrying out vector space projection on the multidimensional signal characteristics of the cable grounding system sample to obtain a standardized characteristic vector of the cable grounding system sample; And carrying out association packaging on the standardized feature vector, a defect type label corresponding to the cable grounding system sample, a sample identifier and acquisition environment parameters to obtain a fault feature database of the cable grounding system.
7. The method for detecting the defects of the cable grounding system according to claim 6, wherein the step of regularly summarizing the prestored knowledge of the failure mechanism field and the core feature expression pattern to obtain the feature defect mapping table of the cable grounding system comprises the following steps: based on the prestored knowledge of the fault mechanism field, carrying out rule refinement on the typical physical defect type to obtain a rule knowledge base of the cable grounding system; Consistency verification is carried out on the rule knowledge base and the core feature expression mode, and a verification result of the core feature expression mode is obtained; Based on the verification result, carrying out knowledge-guided optimization on the core feature expression mode to obtain a refined feature mode of the core feature expression mode; And carrying out mode type binding on the refining characteristic mode and the typical physical defect type to obtain a characteristic defect mapping table of the cable grounding system.
8. The method for detecting the defects of the cable grounding system in an electrified manner according to claim 1, wherein the steps of searching and comparing the multi-dimensional signal feature vector detected on site with the fault feature database, and intelligently diagnosing the comparison result based on a mixed expert network to obtain the specific defect type and severity of the cable grounding system comprise the following steps: Performing data reduction on the multi-dimensional signal feature vector detected on site based on the standardized parameters of the fault feature database to obtain a standardized on-site feature vector of the multi-dimensional signal feature vector; inputting the standardized field feature vector into a hybrid expert network, and calculating probability distribution of the standardized field feature vector to expert network processing through a gate control network of the hybrid expert network; Based on the probability distribution, carrying out collaborative inference on the standardized field feature vector to obtain diagnosis output of the cable grounding system; and based on the probability distribution, carrying out data aggregation on the diagnosis output to obtain the specific defect type and severity of the cable grounding system.
9. The method for detecting the defect electrification of the cable grounding system according to claim 8, wherein the probability distribution is calculated as follows: ; In the formula, For the normalized field feature vector Is allocated to the first The probability of the individual expert network processing is, Is the first The weight vectors associated with the individual expert networks, Is the first The bias term associated with the individual expert network, Is the preset super-parameter of the ultrasonic wave, In order to penalize the term function, To normalize the index operation on vectors in brackets.
10. The method for detecting the defects of the cable grounding system according to claim 1, wherein situation determination is performed on the specific defect type and the severity to obtain early warning information of the cable grounding system, and the method comprises the following steps: determining an early warning level of the cable grounding system according to the specific defect type and the severity; Performing maintenance knowledge mining on the early warning level and the maintenance history of similar defects recorded in the fault characteristic database to obtain early warning description and treatment suggestion of the cable grounding system; And packaging the early warning grade, the early warning description and the treatment suggestion as early warning information of the cable grounding system.

Description

Electrified detection method for defects of cable grounding system Technical Field The invention relates to the technical field of cable detection, in particular to a method for detecting defects of a cable grounding system in an electrified mode. Background The cable grounding system is used as an important guarantee for safe operation of the power system, and the accuracy and timeliness of the defect live detection directly influence the operation and maintenance quality of the power grid. The current traditional detection method lacks accurate frequency domain analysis and complex deconstruction means in a signal processing link, and effective components in loop impedance are difficult to effectively separate, so that electric characteristics related to defects are not comprehensively captured, and further the reliability of defect judgment is affected. The prior art has obvious defects in the aspects of feature extraction and diagnosis modeling, the integration of multidimensional signal features is lack of scientificity, the construction of a fault feature database is insufficient to combine the physical mechanism and actual operation data of typical defects, the suitability of a diagnosis model is poor, detection information under complex working conditions cannot be processed efficiently, and the defect type identification and severity assessment are long in time consumption and insufficient in accuracy, so that how to improve the defect live detection efficiency of a cable grounding system becomes a problem to be solved urgently. Disclosure of Invention The invention provides a cable grounding system defect live detection method for solving the problems in the background technology. In order to achieve the above object, the present invention provides a method for detecting a cable grounding system defect in an electrified manner, comprising: s1, injecting a low-frequency detection current signal into a cable grounding system, and synchronously collecting a response voltage signal generated by the low-frequency detection current signal in the cable grounding system; S2, carrying out frequency domain decomposition on the response voltage signal and the low-frequency detection current signal to obtain loop impedance of the cable grounding system, and carrying out complex deconstruction on the loop impedance to obtain an equivalent pure resistance value of the loop impedance; S3, carrying out state characterization on the equivalent pure resistance value and the waveform of the response voltage signal to obtain a multidimensional signal characteristic of the cable grounding system; S4, performing pattern matching on the multidimensional signal characteristics based on typical physical defect types of the cable grounding system to obtain a characteristic defect mapping table of the cable grounding system, and constructing a fault characteristic database of the cable grounding system according to the characteristic defect mapping table; s5, searching and comparing the multi-dimensional signal feature vector detected on site with the fault feature database, and performing intelligent diagnosis on the comparison result based on a hybrid expert network to obtain the specific defect type and severity of the cable grounding system; s6, situation research and judgment are carried out on the specific defect type and the severity degree, and early warning information of the cable grounding system is obtained. In a preferred embodiment, the injecting the low frequency probing current signal into the cable grounding system and synchronously collecting the response voltage signal generated by the low frequency probing current signal in the cable grounding system comprises: Inputting a low-frequency detection current signal to a grounding down wire of a cable grounding system; receiving an induced current of a loop in the ground down conductor; And collecting the voltage generated by the induced current on the cable grounding system to obtain a response voltage signal of the cable grounding system. In a preferred embodiment, the frequency-domain decomposing the response voltage signal and the low-frequency detection current signal to obtain a loop impedance of the cable grounding system, and performing complex deconstruction on the loop impedance to obtain an equivalent pure resistance value of the loop impedance, including: Filtering and extracting the response voltage signal and the low-frequency detection current signal to obtain a target frequency voltage signal and a current signal of the cable grounding system; Performing frequency domain transformation on the target frequency voltage signal and the current signal to obtain fundamental wave voltage phasors and fundamental wave current phasors of the cable grounding system; Carrying out complex quotient operation on the fundamental voltage phasor and the fundamental current phasor to obtain loop impedance of the cable grounding system; and (3) carrying out resis