High-voltage cable partial discharge detection method and system, and medium

Abstract

The invention discloses a high-voltage cable partial discharge detection method and system and a medium, and relates to the technical field of electrical quantity detection. A capacitive coupling sensor and detection equipment are constructed based on high-voltage electrical equipment; injecting a first signal into the high-voltage cable through the capacitive coupling type sensor based on the detection equipment, and collecting a feedback signal; judging whether the high-voltage cable is subjected to partial discharge or not based on the feedback signal, and obtaining the discharge intensity when the partial discharge occurs; according to the scheme, the method and the structure are improved on the basis of an existing partial discharge detection technology, signals are injected by means of a capacitance coupling type sensor of a high-voltage live display device which is widely applied at present, and real-time live detection of high-voltage electrical equipment such as a switch cabinet, a ring main unit and a cable branch box is achieved. On-site detection work efficiency and detection precision are greatly improved, urgency and necessity of large-scale installation of intelligent online monitoring equipment are reduced at the same time, and maximization of operation and maintenance quality and efficiency of a power distribution equipment operation and maintenance overhaul technology is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical quantity detection, and in particular to a method, system and medium for detecting partial discharge of a high-voltage cable. Background Art

[0002] According to incomplete statistics, more than 80% of power outages in the power system come from faults in the distribution network system. Improving the safety and reliability of the distribution network is of great practical significance for improving the safe and economic operation of the entire power grid. Widely promoting intelligent operation and maintenance technology in the distribution network system is a basic way to ensure the safe operation of the distribution network system, reduce operation and maintenance costs, and improve operation and maintenance efficiency. However, in the specific engineering practice of promoting intelligent operation and maintenance technology of the distribution network system, the equipment operation and management departments of power supply and power supply enterprises have to consider the dual constraints of economic factors and technical factors.

[0003] Switchgear, ring network cabinets, cable branch boxes, etc. are the largest number of equipment assets in power grid companies. These equipments not only have a wide variety of forms and complex and changeable electrical structures, but also have a wide distribution of installation locations and a relatively harsh operating environment, which objectively puts higher requirements on the universality of operation and maintenance technology. At the same time, the unit cost of these equipments is generally low, and the intelligent operation and maintenance technology of equipment based on advanced online monitoring technology can only be selectively promoted due to economic factors.

[0004] Around 2005, the concept and technology of intelligent operation and maintenance technology for power distribution equipment began to be introduced into China, and many equipment hidden dangers were discovered and eliminated in many large-scale power supply guarantee tasks. After more than ten years of research and exploration, the intelligent operation and maintenance technology of distribution network systems has basically formed two different technical routes in China. One is the routine inspection technology based on live detection technology and equipment, and the other is the online health status monitoring technology based on the intelligent technology of electrical equipment. At present, both types of technologies have been supported by many engineering practices, but they also generally have their own shortcomings.

[0005] The main disadvantages of routine inspection technology are: (1) Live detection technology based on transient ground voltage, ultrasonic and ultra-high frequency detection technology generally has the problem of low sensitivity and applicability; (2) With the reality that the sealing of electrical equipment is continuously enhanced, the shielding performance of the equipment electrical structure against internal transient ground voltage, ultra-high frequency and ultrasonic signals is enhanced, resulting in the continuous reduction of the effectiveness of these detection equipment; (3) These detection technologies generally have the problem of too many detection points and low efficiency of on-site live detection; (4) In essence, the above-mentioned detection methods achieve full coverage of equipment defect types through the complementarity of technical applicability, but the diagnostic standards and methods of various types of detection data are independent of each other, which objectively leads to confusion in the understanding of different detection methods, data and defect diagnosis conclusions.

[0006] The main disadvantages of online health status monitoring technology are: (1) the low cost of distribution equipment and the large scale of equipment restrict the manufacturing and engineering costs of intelligent devices; (2) the low manufacturing cost limits the functional improvement of intelligent devices; (3) the operating environment such as high temperature, high humidity, lack of communication and power supply resources brings challenges to intelligent devices; (4) the data security challenges faced by remote data transmission. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing transient ground voltage, ultrasonic and ultra-high frequency detection technologies have low measurement accuracy, and the results are difficult to quantify and intuitively display. In addition, when used for high-voltage cable detection directly connected to high-voltage electrical equipment, there is a problem of difficult installation and deployment. The purpose of the present invention is to provide a high-voltage cable partial discharge detection method, system and medium, which improves the method and structure on the basis of the existing partial discharge detection technology, cleverly borrows the capacitive coupling sensor injection signal of the currently widely used high-voltage live display device, realizes real-time live detection of high-voltage electrical equipment such as switch cabinets, ring network cabinets, cable branch boxes, etc., greatly improves the efficiency and detection accuracy of on-site detection operations, and reduces the urgency and necessity of large-scale installation of intelligent online monitoring equipment, so as to maximize the operation and maintenance quality and efficiency of distribution equipment operation and maintenance inspection technology.

[0008] The present invention is achieved through the following technical solutions:

[0009] This solution provides a method for detecting partial discharge of a high-voltage cable, wherein the high-voltage cable is directly connected to a high-voltage electrical device; the method comprises:

[0010] Construct capacitively coupled sensors and detection equipment based on high voltage electrical equipment;

[0011] Based on the detection device, a first signal is injected into the high-voltage cable through a capacitive coupling sensor, and a feedback signal is collected;

[0012] Whether partial discharge occurs in the high-voltage cable is determined based on the feedback signal, and the discharge intensity is obtained when partial discharge occurs.

[0013] Working principle of this scheme: The existing transient ground voltage, ultrasonic and ultra-high frequency detection technologies have low measurement accuracy, and the results are difficult to quantify and intuitively display. In addition, when used for high-voltage cable detection directly connected to high-voltage electrical equipment, there is a problem of difficult installation and deployment. The purpose of the present invention is to provide a high-voltage cable partial discharge detection method, system and medium, which improves the method and structure on the basis of the existing partial discharge detection technology, cleverly borrows the capacitive coupling sensor injection signal of the currently widely used high-voltage live display device, and realizes real-time live detection of high-voltage electrical equipment such as switch cabinets, ring network cabinets, and cable branch boxes, greatly improving the efficiency and detection accuracy of on-site detection operations, while reducing the urgency and necessity of large-scale installation of intelligent online monitoring equipment, so as to maximize the quality and efficiency of distribution equipment operation and maintenance.

[0014] A further optimization scheme is that the capacitive coupling sensor and detection equipment are constructed based on high-voltage electrical equipment; including the method:

[0015] S1, obtain the high-voltage live display device of the electrical equipment, determine whether the current high-voltage live display device has a core phase hole, if so, use the core phase hole as the first interface end, and use the ground port of the current high-voltage live display device as the second interface end, and enter step S3; otherwise, enter step S2;

[0016] S2, set the current sensing units to be respectively deployed on the high-voltage cable leads of the current high-voltage live display device, one end of the current sensing unit is connected to the high-voltage cable lead of the current high-voltage live display device, and the other end is used as the first interface end, and the ground port of the current high-voltage live display device is used as the second interface end, and enter step S3;

[0017] S3, configuring a partial discharge detection circuit to obtain a feedback signal, wherein one end of the partial discharge detection circuit is connected to the first interface end, and the other end of the partial discharge detection circuit is connected to the second interface end.

[0018] A further optimized solution is to further include a low impedance circuit, wherein the low impedance circuit includes a resistor Zm;

[0019] One end of the resistor Zm is connected to the first interface end, and the other end is connected to the second interface end.

[0020] A further optimized solution is that the partial discharge detection circuit includes a first signal generating device, and the first signal generating device is a pulse current signal generating device.

[0021] A further optimized solution is that the partial discharge detection circuit further includes a current intensity acquisition unit and a data processing unit.

[0022] The current intensity acquisition unit is used to collect feedback signals, and the data processing unit is used to first separate the high-frequency pulse current signal and the industrial frequency current signal from the feedback signal, then extract the discharge intensity from the high-frequency pulse current signal, and extract the standard square wave signal from the industrial frequency current signal.

[0023] A further optimization scheme is that the partial discharge detection circuit also includes an analysis unit; the analysis unit is used to construct a phase-resolved pulse sequence signal reflecting the partial discharge of the high-voltage cable based on the discharge intensity and the standard square wave signal, and identify the health status of the high-voltage cable according to the phase-resolved pulse sequence signal.

[0024] A further optimized solution is that the partial discharge detection circuit also includes a control unit for controlling the frequency and magnitude of the pulse current signal emitted by the pulse current signal generating device.

[0025] A further optimization solution is that a low-voltage capacitor is integrated inside the high-voltage charged display device.

[0026] The present solution also provides a high-voltage cable partial discharge detection system, which is used to implement the above-mentioned high-voltage cable partial discharge detection method, and the system includes:

[0027] A first building block is used to build a capacitively coupled sensor and detection equipment based on high-voltage electrical equipment;

[0028] A detection and acquisition module, used to inject a first signal into the high-voltage cable through a capacitive coupling sensor based on a detection device, and to acquire a feedback signal;

[0029] The judgment module is used to judge whether partial discharge occurs in the high-voltage cable based on the feedback signal, and obtain the discharge intensity when partial discharge occurs.

[0030] The present solution also provides a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement a high-voltage cable partial discharge detection method as described above.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] 1. A method, system and medium for detecting partial discharge of high-voltage cables provided by the present invention improve the method and structure on the basis of the existing partial discharge detection technology, and cleverly use the capacitive coupling sensor injection signal of the currently widely used high-voltage live display device to realize real-time live detection of high-voltage electrical equipment such as switch cabinets, ring network cabinets, cable branch boxes, etc., greatly improve the efficiency and detection accuracy of on-site detection operations, and at the same time reduce the urgency and necessity of large-scale installation of intelligent online monitoring equipment, so as to maximize the quality and efficiency of operation and maintenance of distribution equipment operation and maintenance.

[0033] 2. The present invention provides a method, system and medium for detecting partial discharge of high-voltage cables. Based on the core phase hole of the high-voltage live display device, the equipment is detected and analyzed for live partial discharge, and real-time discharge detection of equipment such as switch cabinets, ring network cabinets, and cable branch boxes is realized. It is applied to the routine inspection and operation and maintenance of distribution cable equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0035] Figure 1 It is a flow chart of a method for detecting partial discharge of high voltage cables;

[0036] Figure 2 It is a schematic diagram of the basic working principle of the high voltage live display device;

[0037] Figure 3 This is a structural diagram of a high-voltage cable partial discharge detection system;

[0038] Figure 4 This is a schematic diagram of the direct-connection test fixture structure;

[0039] Figure 5 A is a schematic diagram of a transfer test fixture;

[0040] Figure 6 It is the schematic diagram of the transfer test fixture B;

[0041] Figure 7 It is a schematic diagram of impedance matching signal conversion circuit;

[0042] Figure 8 It is a schematic diagram of the data storage process;

[0043] Fig. 9 This is a schematic diagram of the PRPS information display effect;

[0044] Fig.10 This is a schematic diagram of the inspection and results of switch #1 of the 10kV #1 ring main unit;

[0045] Fig.11 This is a schematic diagram of the inspection and results of switch #3 of the 10kV #1 ring main unit;

[0046] Fig.12 This is a schematic diagram of the inspection and results of switch #4 of the 10kV #1 ring main unit;

[0047] Fig.13 This is a schematic diagram of the inspection and results of switch #5 of the 10kV #1 ring main unit;

[0048] Fig.14 This is a partial enlarged schematic diagram of the assembly. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0050] The existing transient ground voltage, ultrasonic and ultra-high frequency detection technologies have low measurement accuracy, and the results are difficult to quantify and intuitively display. In addition, when applied to high-voltage cable detection directly connected to high-voltage electrical equipment, there is a problem of difficult installation and deployment. In view of this, this solution provides the following embodiments to solve the above technical problems:

[0051] Example 1

[0052] This embodiment provides a method for detecting partial discharge of a high-voltage cable. Figure 1 As shown, the high-voltage cable is directly connected to a high-voltage electrical device; the method comprises:

[0053] Step 1: construct a capacitive coupling sensor and detection equipment based on high-voltage electrical equipment; this step specifically includes the following methods:

[0054] S1, obtain the high-voltage live display device of the electrical equipment, determine whether the current high-voltage live display device has a core phase hole, if so, use the core phase hole as the first interface end, and use the ground port of the current high-voltage live display device as the second interface end, and enter step S3; otherwise, enter step S2;

[0055] S2, set the current sensing units to be respectively deployed on the high-voltage cable leads of the current high-voltage live display device, one end of the current sensing unit is connected to the high-voltage cable lead of the current high-voltage live display device, and the other end is used as the first interface end, and the ground port of the current high-voltage live display device is used as the second interface end, and enter step S3;

[0056] S3, configuring a partial discharge detection circuit to obtain a feedback signal, wherein one end of the partial discharge detection circuit is connected to the first interface end, and the other end of the partial discharge detection circuit is connected to the second interface end.

[0057] The partial discharge detection circuit further includes a low impedance circuit, which includes a resistor Zm; one end of the resistor Zm is connected to the first interface end, and the other end is connected to the second interface end.

[0058] The partial discharge detection circuit comprises a first signal generating device, which is a pulse current signal generating device.

[0059] Step 2: injecting a first signal into the high-voltage cable through a capacitive coupling sensor based on the detection device, and collecting a feedback signal;

[0060] Step three: determine whether partial discharge occurs in the high-voltage cable based on the feedback signal, and obtain the discharge intensity when partial discharge occurs.

[0061] The partial discharge detection circuit also includes a current intensity acquisition unit and a data processing unit.

[0062] The current intensity acquisition unit is used to collect feedback signals, and the data processing unit is used to first separate the high-frequency pulse current signal and the industrial frequency current signal from the feedback signal, then extract the discharge intensity from the high-frequency pulse current signal, and extract the standard square wave signal from the industrial frequency current signal.

[0063] The partial discharge detection circuit also includes an analysis unit; the analysis unit is used to construct a phase-resolved pulse sequence signal reflecting the partial discharge of the high-voltage cable based on the discharge intensity and the standard square wave signal, and identify the health status of the high-voltage cable according to the phase-resolved pulse sequence signal.

[0064] The partial discharge detection circuit also includes a control unit for controlling the frequency and magnitude of the pulse current signal emitted by the pulse current signal generating device.

[0065] The high-voltage charged display device is internally integrated with a low-voltage capacitor.

[0066] The basic working principle of high voltage live display device is as follows Figure 2 As shown. The capacitive coupling sensor of the high-voltage live display device is essentially a ceramic capacitor core rod cast inside the supporting insulator, one end of which is connected to the busbar of the high-voltage electrical equipment, and the other end is separately led out at the tail end of the supporting insulator. Therefore, from the perspective of circuit analysis, the high-voltage live display device is essentially a special form of capacitor. It is equivalent to the high-voltage capacitor C in the figure. H The high voltage live display device is internally integrated with a low voltage capacitor C L The high voltage side is connected to the terminals ac and indicator L of the live display device. a -L c and nuclear phase hole H a -H c When the high-voltage bus is energized, the voltage divider circuit composed of the high-voltage capacitor and the low-voltage capacitor will generate a power frequency voltage of up to tens of volts between the core phase hole and the high-voltage end of the indicator, and drive the indicator to light up. a -Hc Low impedance connection branch Z between the ground loop m When conducting a partial discharge field test, as long as the detection impedance under high frequency conditions is sufficiently lower than the port impedance of the high voltage live display device, most of the high frequency current flowing through the capacitive coupling sensor will enter the interior of the detector through the test line (I a1 ), thereby achieving the purpose of partial discharge live detection.

[0067] Example 2

[0068] This embodiment provides a high-voltage cable partial discharge detection system, which is used to implement a high-voltage cable partial discharge detection method described in Embodiment 1. Figure 3 As shown, the system comprises:

[0069] A first building block is used to build a capacitively coupled sensor and detection equipment based on high-voltage electrical equipment;

[0070] A detection and acquisition module, used to inject a first signal into the high-voltage cable through a capacitive coupling sensor based on a detection device, and to acquire a feedback signal;

[0071] The judgment module is used to judge whether partial discharge occurs in the high-voltage cable based on the feedback signal, and obtain the discharge intensity when partial discharge occurs.

[0072] A second interface terminal and a first interface terminal are determined on the high-voltage live display device, and a partial discharge detection circuit is configured to obtain a feedback signal, one end of the partial discharge detection circuit is connected to the first interface terminal, and the other end of the partial discharge detection circuit is connected to the second interface terminal. The partial discharge detection circuit also includes a low impedance circuit, and the low impedance circuit includes a resistor Zm; one end of the resistor Zm is connected to the first interface terminal, and the other end is connected to the second interface terminal;

[0073] Specifically, the core phase hole of the high-voltage live display device is connected to the partial discharge detection circuit through the test fixture; according to the specific model of the high-voltage live display device, two methods can be used: direct-connection test fixture and transfer test fixture:

[0074] Direct-connect test fixture: Its basic form is a forked cable with special requirements, such as Figure 4As shown, one forked end a is connected to the core phase hole of the high-voltage live display device through a banana plug, and the other forked end b is connected to the grounding part with exposed metal such as the high-voltage switch cabinet and the cable branch box through an alligator clip. The other end of the forked cable is connected to the input port of the partial discharge detection circuit. In addition, the forked end a is a modular type, which is matched with similar banana plugs c of different specifications and sizes to adapt to high-voltage live display devices with different core phase hole sizes. For high-voltage live display devices without core phase holes, the forked end a can also extend probes of different lengths to directly contact the exposed metal terminals of the input signal of the high-voltage live display device for detection. For high-voltage live display devices with plug-in wiring, the probe can also be used to detect the exposed metal part of the sensor output end.

[0075] Transfer test fixture: The direct-connection test fixture requires manual introduction of high-frequency pulse current into the data acquisition device. It is essentially a shunt sensing method. The test data will be affected by the impedance of the data acquisition device, the test fixture and the grounding loop, and is closely related to the internal component parameters of the high-voltage live display device. In addition, for high-voltage live display devices without core phase holes, in order to improve the test accuracy, it may even be necessary to manually remove the signal leads of the high-voltage live display device for partial discharge detection. If the recovery work after the test is not thorough, it can easily cause safety hazards. Therefore, a transfer test fixture is provided.

[0076] The transfer test fixture includes a test cable and a current sensing unit assembled together, such as Figure 5 and Figure 6 As shown, the terminals at both ends of the test cable can be banana plugs A and alligator clips B, and the output signal terminal C can be a radio frequency terminal of appropriate specifications. The banana plug A can be combined to match the high-voltage live display device with different sizes of core phase holes.

[0077] The essence of the current sensing unit in this embodiment is a radio frequency magnetic field sensor, which is used to couple the high-frequency magnetic field generated by the high-frequency current in the test cable and convert it into a corresponding high-frequency current output. Since there is no direct electrical coupling between the test cable and the output signal end, the anti-interference ability is strong, and in theory, there is no need to disconnect the input signal lead of the high-voltage live display.

[0078] For high-voltage live display devices that do not have core phase holes, the current sensing unit can also be installed in a fixed manner, and the combination with the input signal lead of the high-voltage live display device is called a fixed-installation transfer test fixture that can provide test functions.

[0079] The current sensing unit (CSD) can be deployed on the three-phase signal leads to support the phase detection function; it can also be deployed on the ground lead alone to support only the three-phase simultaneous measurement function. The current sensing unit can be designed as a closed type or an open type according to the detection needs.

[0080] The partial discharge pulse signal is a burst pulse signal with a very short duration. Due to its short duration, it is often necessary to perform high-speed data acquisition on the input signal and store a sufficient number of sampling points to capture the partial discharge pulse signal that meets the measurement accuracy requirements, but this will undoubtedly greatly increase the requirements for large-capacity storage space for the hardware circuit.

[0081] The partial discharge detection circuit also includes a current intensity acquisition unit and a data processing unit.

[0082] The current intensity acquisition unit is used to collect feedback signals, and the data processing unit is used to first separate the high-frequency pulse current signal and the industrial frequency current signal from the feedback signal, then extract the discharge intensity from the high-frequency pulse current signal, and extract the standard square wave signal from the industrial frequency current signal.

[0083] The partial discharge detection circuit comprises a first signal generating device, which is a pulse current signal generating device.

[0084] The data processing unit includes an impedance matching signal conversion unit, which is used to theoretically reduce the impedance of the input loop to zero based on an active circuit and using the concept of virtual short, so as to minimize the influence of the impedance of the high-voltage live indicator on the partial discharge measurement; Figure 7 As shown, the main function of the impedance matching signal conversion circuit is to first separate the high-frequency pulse current signal and the industrial frequency current signal in the input current signal, and output them to different signal conditioning circuits respectively; secondly, the high-frequency pulse current signal is output to the partial discharge detection circuit for extracting the strength information of the partial discharge activity signal; then the industrial frequency current signal is output to the phase synchronization circuit and shaped into a standard square wave signal with the same frequency as the industrial frequency voltage, which is used to extract the phase information of the partial discharge activity signal.

[0085] The partial discharge detection circuit also includes an analysis unit; the analysis unit is used to construct a phase-resolved pulse sequence signal reflecting the partial discharge of the high-voltage cable based on the discharge intensity and the standard square wave signal, and identify the health status of the high-voltage cable based on the phase-resolved pulse sequence signal. Specifically, the phase-resolved pulse sequence signal is used to perform data sequence noise reduction, characteristic parameter calculation, automatic defect type identification and other advanced measurement and diagnosis functions to obtain the health status of the high-voltage cable.

[0086] The partial discharge detection circuit also includes a control unit for controlling the frequency and magnitude of the pulse current signal emitted by the pulse current signal generating device.

[0087] The high voltage live display device has a low voltage capacitor integrated inside.

[0088] like Figure 8 As shown, the scheme designs a small-capacity storage space that can be cyclically read and written to store continuously collected data information that meets the length requirement; the continuously running analog or digital watchdog technology can be automatically triggered when the threshold setting range is exceeded, and the automatic transfer of the discharge pulse digital information can be started; the software processes the automatically transferred discharge pulse waveform data to obtain the amplitude information of the discharge pulse; at the watchdog triggering moment, the software can automatically read the counting information of the phase timer to obtain the phase information of the current discharge pulse; the amplitude information and phase information of the discharge pulse are combined into data pairs and arranged in the order of appearance, so as to obtain the phase-resolved pulse sequence information (PRPS) reflecting the local discharge activity; the phase-resolved pulse sequence information (PRPS) obtained within the set time window is transmitted to the data processing device, and the data processing device performs higher-level data mining, so as to realize feature parameter extraction, health status warning, automatic identification of defect types and other advanced functions.

[0089] The data processing unit consists of a rugged tablet computer and professional application software running on it. Rugged computers have powerful computing capabilities, rich communication interface resources, huge data storage capabilities and large-screen display screens, which can provide the computing power and storage support required for advanced data processing, as well as a friendly human-computer interaction interface.

[0090] like Fig. 9 As shown, this solution displays the collected PRPS information in an appropriate form, performs diagnostic analysis based on the data sequence information provided by PRPS, and issues necessary health status warning information; performs storage and query management on the test data of different equipment objects, which is convenient for testers to trace the test results afterwards. For valuable test data, it can be exported to the internal typical case library to guide the improvement of the professional knowledge of testers; perform in-depth diagnostic analysis on the recorded test data according to the project, which is convenient for testers to understand and analyze specific test events from various dimensions;

[0091] This embodiment applies the device provided by this solution and has completed the partial discharge detection of cable joints in the ring network cabinets and branch boxes of 8 lines such as 10kV phase cow line, 10kV Zhuangda third line, 10kV Zhuangda second line, 10kV Zhuangda first line, 10kV Zhuangle line, 10kV Zhuangwei first line, 10kV Zhuangwei second line, and 10kV Chengxin ring in a certain area. The installation diagram of the 10kV #1 ring network cabinet #1, #3-#5 switch detection diagram and the detection results are shown as follows Figure 10-14A total of 143 ring network cabinets and branch boxes were tested, and 398 switch cabinets were tested. The test results of the 10kV Fupeng line are shown in the following table:

[0092] 10kV Fupeng Line Test Results

[0093]

[0094]

[0095] Example 3

[0096] This embodiment provides a computer-readable medium, on which a computer program is stored. The computer program is executed by a processor to implement a high-voltage cable partial discharge detection method as described in Embodiment 1, specifically performing the following steps:

[0097] Step 1: construct capacitive coupling sensors and detection equipment based on high-voltage electrical equipment;

[0098] Step 2: injecting a first signal into the high-voltage cable through a capacitive coupling sensor based on the detection device, and collecting a feedback signal;

[0099] Step three: determine whether partial discharge occurs in the high-voltage cable based on the feedback signal, and obtain the discharge intensity when partial discharge occurs.

[0100] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting partial discharge of a high voltage cable, characterized in that: The high-voltage cable is directly connected to a high-voltage electrical device; the method comprises: Construct capacitively coupled sensors and detection equipment based on high voltage electrical equipment; Based on the detection device, a first signal is injected into the high-voltage cable through a capacitive coupling sensor, and a feedback signal is collected; Whether partial discharge occurs in the high-voltage cable is determined based on the feedback signal, and the discharge intensity is obtained when partial discharge occurs.

2. A method for detecting partial discharge of a high-voltage cable according to claim 1, characterized in that: The capacitive coupling sensor and detection equipment are constructed based on high-voltage electrical equipment; including method: S1, obtain a high-voltage live display device of the electrical equipment, determine whether the current high-voltage live display device has a core phase hole, if so, use the core phase hole as the first interface end, and use the ground port of the current high-voltage live display device as the second interface end, and enter step S3; Otherwise, proceed to step S2; S2, set the current sensing units to be respectively deployed on the high-voltage cable leads of the current high-voltage live display device, one end of the current sensing unit is connected to the high-voltage cable lead of the current high-voltage live display device, and the other end is used as the first interface end, and the ground port of the current high-voltage live display device is used as the second interface end, and enter step S3; S3, configuring a partial discharge detection circuit to obtain a feedback signal, wherein one end of the partial discharge detection circuit is connected to the first interface end, and the other end of the partial discharge detection circuit is connected to the second interface end.

3. A method for detecting partial discharge of a high-voltage cable according to claim 2, characterized in that: Also included is a low impedance circuit, the low impedance circuit comprising a resistor Zm; One end of the resistor Zm is connected to the first interface end, and the other end is connected to the second interface end.

4. A method for detecting partial discharge of a high-voltage cable according to claim 3, characterized in that: The partial discharge detection circuit comprises a first signal generating device, which is a pulse current signal generating device.

5. A method for detecting partial discharge of a high-voltage cable according to claim 2, characterized in that: The partial discharge detection circuit also includes a current intensity acquisition unit and a data processing unit. The current intensity acquisition unit is used to collect feedback signals, and the data processing unit is used to first separate the high-frequency pulse current signal and the industrial frequency current signal from the feedback signal, then extract the discharge intensity from the high-frequency pulse current signal, and extract the standard square wave signal from the industrial frequency current signal.

6. A method for detecting partial discharge of a high-voltage cable according to claim 5, characterized in that: The partial discharge detection circuit also includes an analysis unit; the analysis unit is used to construct a phase-resolved pulse sequence signal reflecting the partial discharge of the high-voltage cable based on the discharge intensity and the standard square wave signal, and identify the health status of the high-voltage cable according to the phase-resolved pulse sequence signal.

7. A method for detecting partial discharge of a high-voltage cable according to claim 4, characterized in that: The partial discharge detection circuit also includes a control unit for controlling the frequency and magnitude of the pulse current signal emitted by the pulse current signal generating device.

8. A method for detecting partial discharge of a high-voltage cable according to claim 1, characterized in that: The high-voltage charged display device is internally integrated with a low-voltage capacitor.

9. A high voltage cable partial discharge detection system, characterized in that: A method for detecting partial discharge of a high-voltage cable according to any one of claims 1 to 8, the system comprising: A first building block is used to build a capacitively coupled sensor and detection equipment based on high-voltage electrical equipment; A detection and acquisition module, used to inject a first signal into the high-voltage cable through a capacitive coupling sensor based on a detection device, and to acquire a feedback signal; The judgment module is used to judge whether partial discharge occurs in the high-voltage cable based on the feedback signal, and obtain the discharge intensity when partial discharge occurs.

10. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement a high-voltage cable partial discharge detection method as described in any one of claims 1 to 8.

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