CN-116008723-B - Cable fault judging method, device, electronic equipment, system and storage medium

CN116008723BCN 116008723 BCN116008723 BCN 116008723BCN-116008723-B

Abstract

The invention provides a method, a device, electronic equipment, a system and a storage medium for judging cable faults. The method comprises the steps of obtaining a first insulation temperature and a first initial voltage of a cable joint at a current surface temperature when partial discharge of the cable joint of a detected cable is detected for the first time, heating the cable joint to different surface temperatures, obtaining a second insulation temperature of the cable joint at each surface temperature, adjusting the power supply voltage of the cable joint at each second insulation temperature, recording the power supply voltage when the cable joint is subjected to partial discharge at the second insulation temperature as a corresponding second initial voltage, obtaining the change trend of the initial voltage along with the insulation temperature when the cable joint is subjected to partial discharge based on the first insulation temperature, the first initial voltage, all the second insulation temperatures and all the second initial voltages, and judging whether the detected cable is faulty according to the change trend. The invention can effectively improve the accuracy of fault judgment of the detected cable.

Inventors

SU JINGANG
PANG XIANHAI
ZHANG PENG
HUANG XINGWANG
JIANG YIHU
Lv Yaya

Assignees

国网河北省电力有限公司电力科学研究院
国家电网有限公司
国网河北能源技术服务有限公司

Dates

Publication Date: 20260512
Application Date: 20221215

Claims (10)

1. The method for judging the cable faults is characterized by comprising the following steps of: when partial discharge of a cable joint of a detected cable is detected for the first time, acquiring a first insulation temperature and a first initial voltage of the cable joint at the current surface temperature; heating the cable joint to different surface temperatures and obtaining a second insulation temperature of the cable joint at each surface temperature; Adjusting the power supply voltage of the cable connector at each second insulation temperature, and recording the power supply voltage when the cable connector is subjected to partial discharge at the second insulation temperature as a corresponding second initial voltage; acquiring the variation trend of the initial voltage along with the insulation temperature when the cable joint is subjected to partial discharge based on the first insulation temperature, the first initial voltage, all the second insulation temperatures and all the second initial voltages; judging whether the detected cable fails according to the change trend.
2. The method according to claim 1, wherein the determining whether the detected cable is faulty according to the trend of change includes: and when the change trend is that the initial voltage of the cable connector is changed reversely along with the change of the insulation temperature when partial discharge occurs, determining that the detected cable is in fault.
3. The method of claim 1, wherein said obtaining a second insulation temperature of the cable joint at each surface temperature comprises: And carrying out temperature inversion calculation based on each surface temperature of the cable connector and a preset thermal circuit model to obtain a second insulation temperature of the cable connector at each surface temperature.
4. A device for determining a cable fault, comprising: The initial data acquisition module is used for acquiring a first insulation temperature and a first initial voltage of the cable joint at the current surface temperature when partial discharge of the cable joint of the detected cable is detected for the first time; An insulation temperature acquisition module for heating the cable joint to different surface temperatures and acquiring a second insulation temperature of the cable joint at each surface temperature; The initial voltage acquisition module is used for adjusting the power supply voltage of the cable connector at each second insulation temperature and recording the power supply voltage when the cable connector is subjected to partial discharge at the second insulation temperature as a corresponding second initial voltage; The change trend determining module is used for obtaining the change trend of the initial voltage along with the insulation temperature when the cable joint is subjected to partial discharge based on the first insulation temperature, the first initial voltage, all the second insulation temperatures and all the second initial voltages; And the cable fault judging module is used for judging whether the detected cable has faults or not according to the change trend.
5. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of the preceding claims 1 to 3 when the computer program is executed.
6. A judging system for cable faults is characterized by comprising the electronic equipment as claimed in claim 5, and further comprising a partial discharge measuring device, a temperature control device and a pressurizing device; One end of the partial discharge measuring device is connected with the cable joint of the detected cable, and the other end of the partial discharge measuring device is connected with the electronic equipment and is used for monitoring whether partial discharge occurs to each cable joint of the detected cable; one end of the temperature control device is connected with the cable joint of the detected cable, and the other end of the temperature control device is connected with the electronic equipment and is used for collecting the surface temperature of each cable joint and heating each cable joint to different surface temperatures; One end of the pressurizing device is connected with the electronic equipment, the other end of the pressurizing device is connected with the first end of the detected cable, the metal shielding layer at the second end of the detected cable is grounded, and the pressurizing device is used for applying adjustable power supply voltage to the detected cable.
7. The system according to claim 6, wherein the partial discharge measuring device includes a partial discharge control unit, an optical fiber, and a partial discharge detection sensor and a partial discharge detection unit corresponding to each of the cable joints; For each partial discharge detection sensor, one end of the partial discharge detection sensor is connected with a corresponding cable joint, and the other end of the partial discharge detection sensor is connected with one end of a corresponding partial discharge detection unit, and is used for carrying out partial discharge detection on the corresponding cable joint and correspondingly generating a first electric signal; For each partial discharge detection unit, the other end of the partial discharge detection unit is connected with one end of the partial discharge control unit through the optical fiber and is used for converting the first electric signal into an optical signal; The other end of the partial discharge control unit is connected with the electronic equipment, the partial discharge control unit is used for converting the optical signal output by each partial discharge detection unit into a corresponding second electric signal and sending the second electric signal to the electronic equipment, the electronic equipment is also used for generating a control signal based on the second electric signal, and the partial discharge control unit is also used for controlling each partial discharge detection sensor to start or stop carrying out partial discharge detection on a corresponding cable joint based on the control signal sent by the electronic equipment.
8. The system for judging cable faults according to claim 6, wherein the temperature control device comprises a heating belt, a temperature acquisition card and a temperature controller; The heating belts are arranged at each cable joint and are used for heating the corresponding cable joints; the temperature acquisition card is arranged at each cable joint, the first end of the temperature acquisition card is connected with the electronic equipment, and the second end of the temperature acquisition card is connected with the corresponding cable joint and is used for acquiring the surface temperature of the corresponding cable joint; The temperature controller is arranged at each cable joint, the first end of the temperature controller is connected with the electronic equipment, the second end of the temperature controller is connected with the heating belt and is used for correspondingly controlling the heating temperature of the heating belt based on a temperature control signal sent by the electronic equipment so as to heat the corresponding cable joints to different surface temperatures.
9. The system according to claim 6, wherein the pressurizing device comprises a variable power supply, a variable frequency control unit, an exciting transformer, a high-voltage resonance reactor, an isolation impedance, a voltage measurement display device and a high-voltage measurement voltage division device; The variable power supply is used as an input power supply and is connected with the input end of the variable frequency control unit; the output end of the variable frequency control unit is connected with the primary side of the exciting transformer; one end of the secondary side of the exciting transformer is grounded, and the other end of the secondary side of the exciting transformer is connected with the input end of the high-voltage resonant reactor; the output end of the high-voltage resonant reactor is respectively connected with the first end of the high-voltage measurement voltage divider and the input end of the isolation impedance device; The output end of the isolation impeder is connected with the first end of the detected cable; the second end of the high-voltage measurement voltage division device is connected with one end of the voltage measurement display device, and the third end of the high-voltage measurement voltage division device is connected with one end of the secondary side of the exciting transformer; The other end of the voltage measurement display device is connected with the input end of the variable frequency control unit and then connected with the electronic equipment.
10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any of the preceding claims 1 to 3.

Description

Cable fault judging method, device, electronic equipment, system and storage medium Technical Field The present invention relates to the field of cable fault determination technologies, and in particular, to a method, an apparatus, an electronic device, a system, and a storage medium for determining a cable fault. Background With the rapid development of the economy and society and the continuous improvement of the urban level, the power demand of China is continuously increased. Therefore, the construction of the urban power transmission line has very important significance for meeting the urban economic development requirement. In the construction of urban power transmission lines, due to lack of urban land resources, overhead line power transmission corridors are often difficult to construct, and the construction of the overhead line power transmission corridors may affect urban landscapes. Therefore, at present, when urban power transmission lines are built, high-voltage power transmission cables with high power transmission corridor utilization rate and high environmental friendliness are mostly adopted. However, when the high-voltage power cable line is actually constructed, the defects of the cable and accessories thereof may be caused by the construction process, the manufacturing process and the product quality. Based on the above, in the subsequent operation process of the high-voltage power cable line, under the comprehensive actions of factors such as an electric field, a thermal field, mechanical force and the like, the defects can cause partial discharge of the high-voltage cable, and finally, breakdown faults are developed. Therefore, it is necessary to perform a partial discharge acceptance test on the finished high-voltage cable, and the situation of defective operation of the high-voltage cable can be effectively avoided through the acceptance test, so that the failure rate of the high-voltage cable can be effectively reduced. In the prior art, when a partial discharge acceptance test is performed on a high-voltage cable, the partial discharge acceptance test is generally performed on the basis of a cable without load under an alternating-current power supply. However, the method has the disadvantage that when strong interference sources exist around the test line, such as a converter station and a signal tower, the test itself is influenced by electromagnetic waves of the surrounding environment, signals other than the cable are easily used as partial discharge defects of the cable, and thus the situation of misjudgment of the defects is caused. Disclosure of Invention The embodiment of the invention provides a method, a device, electronic equipment, a system and a storage medium for judging cable faults, which are used for solving the problem that in the prior art, when a partial discharge acceptance test is carried out on a high-voltage cable, the high-voltage cable is possibly influenced by strong interference sources around a test line, so that the precision of a test result is low. In a first aspect, an embodiment of the present invention provides a method for determining a cable fault, including: when partial discharge of a cable joint of a detected cable is detected for the first time, acquiring a first insulation temperature and a first initial voltage of the cable joint at the current surface temperature; heating the cable joint to different surface temperatures and obtaining a second insulation temperature of the cable joint at each surface temperature; Adjusting the power supply voltage of the cable connector at each second insulation temperature, and recording the power supply voltage when the cable connector is subjected to partial discharge at the second insulation temperature as a corresponding second initial voltage; acquiring the variation trend of the initial voltage along with the insulation temperature when the cable joint is subjected to partial discharge based on the first insulation temperature, the first initial voltage, all the second insulation temperatures and all the second initial voltages; judging whether the detected cable fails according to the change trend. In one possible implementation manner, the determining whether the detected cable fails according to the change trend includes: and when the change trend is that the initial voltage of the cable connector is changed reversely along with the change of the insulation temperature when partial discharge occurs, determining that the detected cable is in fault. In one possible implementation, the obtaining the second insulation temperature of the cable joint at each surface temperature includes: And carrying out temperature inversion calculation based on each surface temperature of the cable connector and a preset thermal circuit model to obtain a second insulation temperature of the cable connector at each surface temperature. In a second aspect, an embodiment of the present invention provides a device for d