Temperature-controllable cable defect partial discharge detection method

Abstract

The embodiment of the invention relates to a temperature-controllable cable defect partial discharge detection method, and the method comprises the steps: constructing an electricity-heat combined platform, arranging a temperature sensor and a partial discharge sensor in a cable defect region, adjusting the current of a conductor to a preset value through a through-flow heating module, and enabling the temperature of the defect region to rise to a target temperature; acquiring partial discharge signals in real time through a partial discharge sensor, synchronously recording data of a temperature sensor, and establishing a time sequence of temperature-partial discharge signals; extracting partial discharge signal characteristic parameters, and calculating a defect area temperature gradient and a thermal response time constant in combination with a heat conduction model; identifying defect types and positioning defect positions. Through temperature active control, the problems that existing partial discharge detection is low in sensitivity and temperature influence is not quantified are solved; by synchronously collecting temperature and partial discharge signals, a temperature-partial discharge characteristic relation is established, the one-sidedness of single parameter analysis in a traditional method is solved, and the accuracy and reliability of high-voltage cable insulation state evaluation are improved.

Description

Background Art

[0002] As the core equipment of power transmission, the insulation status of high-voltage cables is directly related to the safe and stable operation of the power grid. With the rapid growth of urban load, the cable load rate has been rising year by year. High load leads to increased core temperature, accelerated insulation aging, and caused partial discharge (PD) defects, which are the precursor of insulation breakdown. Therefore, accurate detection of PD defects is crucial to ensure cable safety.

[0003] Existing partial discharge detection methods (such as pulse current method, ultrasonic method, and ultra-high frequency method) mainly rely on offline tests or online monitoring under fixed voltage. The influence of temperature is not fully considered. The increase in temperature will reduce the partial discharge starting voltage (for example, the starting voltage of a spike defect drops by about 40% at 80°C), but the current standards (such as GB / T 7354-2018) do not specify the temperature correction method, resulting in a disconnect between the detection results and the actual operating conditions. The partial discharge signal of a tiny defect is weak at room temperature and is easily submerged by noise. The oscillation wave method is not very accurate at 1.7U. 0 The detection threshold for partial discharge of joints over 5 years old is 500pC, which makes it difficult to detect early defects. The existing monitoring system collects temperature and partial discharge data independently, without establishing a coupling relationship, and cannot quantify the accelerating effect of temperature on defect development. Although traditional withstand voltage tests (such as power frequency withstand voltage) can detect defects, they will accelerate insulation aging.

[0004] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the embodiments of the present disclosure is to provide a temperature-controllable method for detecting partial discharge of cable defects, thereby overcoming one or more problems caused by limitations and defects of related technologies at least to a certain extent.

[0007] The present application provides a temperature-controllable cable defect partial discharge detection method, comprising:

[0008] Construct an electric-thermal joint platform, arrange temperature sensors and partial discharge sensors in the cable defect area, and adjust the conductor current to the preset value through the through-current heating module to raise the temperature of the defect area to the target temperature;

[0009] The partial discharge sensor collects partial discharge signals in real time, records temperature sensor data synchronously, and establishes a time series of temperature-partial discharge signals;

[0010] According to the time series of temperature-PD signal, the characteristic parameters of PD signal are extracted, and the temperature gradient and thermal response time constant of defect area are calculated by combining with heat conduction model.

[0011] According to the temperature gradient and thermal response time constant of the defect area, the defect type can be identified and the defect position can be located.

[0012] In a possible implementation, the through-flow heating module includes:

[0013] An adjustable current source, the adjustable current source being coordinated with temperature feedback closed-loop control;

[0014] An infrared thermal imager is used to assist in monitoring the cable surface temperature distribution.

[0015] In a possible implementation manner, the partial discharge sensor includes:

[0016] A high-frequency current transformer, wherein the frequency band coverage range of the high-frequency current transformer is 10kHz to 100MHz;

[0017] The UHF antenna has a frequency band coverage range of 300 MHz to 3 GHz.

[0018] In a possible implementation, the heat conduction model is expressed as:

[0019]

[0020] ρ is the cable material density, c is the specific heat capacity, λ is the thermal conductivity, Q Joule is the Joule heat of the conductor, Q dielectric is the dielectric loss heat, Q defect The curve discharges heat.

[0021] In a possible implementation, the expression for calculating the thermal response time constant is:

[0022]

[0023] Among them, m is the cable mass, c is the specific heat capacity, h is the convection heat transfer coefficient, and A is the heat dissipation area.

[0024] In a possible implementation manner, the characteristic parameters of the partial discharge signal are discharge amount and phase distribution.

[0025] In a possible implementation manner, the defect type is any one of a needle tip defect, an air gap defect, a suspension defect, and a surface defect.

[0026] In a possible implementation manner, the preset value is 300A.

[0027] In a possible implementation, the target temperature is 60°C-90°C.

[0028] In a possible implementation, the electric-thermal combined platform further includes:

[0029] A variable frequency voltage source is used to apply a variable frequency voltage during the detection process to enhance the temperature response of the defect;

[0030] Acoustic emission sensor, used to assist in locating the discharge position.

[0031] The technical solution provided by this application may have the following beneficial effects:

[0032] Through the temperature-controllable cable defect partial discharge detection method of the present application, on the one hand, the temperature of the defect area is raised to the operating temperature through the flow heating module, thereby improving the amplitude of the partial discharge signal; active temperature control is formed, which solves the problems of low sensitivity of existing partial discharge detection and unquantified temperature influence; on the other hand, by synchronously collecting temperature and partial discharge signals, a temperature-partial discharge characteristic relationship is established, which solves the one-sidedness of single parameter analysis of traditional methods and improves the accuracy and reliability of high-voltage cable insulation status assessment.

[0033] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0035] Figure 1 A schematic diagram showing the steps of a method for detecting partial discharge of a temperature-controllable cable defect in an exemplary embodiment of the present disclosure;

[0036] Figure 2 A schematic flow chart of a method for detecting partial discharge of temperature-controllable cable defects in an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0037] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0038] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0039] This example embodiment provides a temperature-controllable cable defect partial discharge detection method. Figure 1 As shown in , the method may include the following steps:

[0040] Step S101: construct an electric-thermal joint platform, arrange temperature sensors and partial discharge sensors in the cable defect area, adjust the conductor current to a preset value through a through-current heating module, and raise the temperature of the defect area to the target temperature.

[0041] Step S102: collecting partial discharge signals in real time through partial discharge sensors, synchronously recording temperature sensor data, and establishing a time series of temperature-partial discharge signals.

[0042] Step S103: extracting characteristic parameters of the partial discharge signal according to the time series of the temperature-partial discharge signal, and calculating the temperature gradient and thermal response time constant of the defect area in combination with the heat conduction model.

[0043] Step S104: Identify the defect type and locate the defect position according to the temperature gradient and thermal response time constant of the defect area.

[0044] Through the above method, on the one hand, the temperature of the defective area is raised to the operating temperature through the flow heating module, thereby improving the amplitude of the partial discharge signal; active temperature control is formed, which solves the problems of low sensitivity of existing partial discharge detection and unquantified temperature influence; on the other hand, by synchronously collecting temperature and partial discharge signals, a temperature-partial discharge characteristic relationship is established, which solves the one-sidedness of single parameter analysis of traditional methods and improves the accuracy and reliability of defect status assessment of high-voltage cables.

[0045] Next, we will refer to Figure 1 to Figure 2 Each step of the above method in this example implementation is described in more detail.

[0046] Step S101: construct an electric-thermal joint platform, arrange temperature sensors and partial discharge sensors in the cable defect area, adjust the conductor current to a preset value through a through-current heating module, and raise the temperature of the defect area to the target temperature.

[0047] In one embodiment, an electric-thermal combined platform is constructed, in which an adjustable current source (preset 300A) is directly connected to the conductor of the cable under test through a copper bus or a large-section cable clamp to form a closed loop. The heating current flows evenly through the defective area of ​​the cable, generating Joule heat. The distributed optical fiber temperature measurement system (DTS) is spirally wound along the surface of the outer sheath of the cable under test to monitor the temperature of the heating area in real time; the infrared thermal imager is fixed directly above the cable under test through a bracket to monitor the surface temperature distribution in a non-contact manner.

[0048] The variable frequency voltage source is connected to the high voltage bushing at the terminal of the cable under test through a high voltage coaxial cable to apply voltage. The voltage regulator is connected in series with the voltage source, and the protection device is connected in parallel at both ends of the cable to prevent overvoltage breakdown. The optical fiber signal of DTS is converted into digital temperature data by a demodulator. The infrared thermal imager transmits the temperature image to the industrial computer through the gigabit network port, which is aligned with the DTS data in time and space. The current signal of the high frequency current transformer (HFCT) is connected to the high frequency acquisition card through a coaxial cable; the ultra-high frequency antenna (UHF) signal is amplified by a low noise amplifier and transmitted to the oscilloscope through a cable. The acoustic emission sensor is connected to the acoustic emission acquisition instrument to synchronously collect ultrasonic signals. The data acquisition card is connected to the industrial computer to synchronously trigger the acquisition of signals from each channel. According to the DTS feedback, the temperature control software sends PID adjustment instructions to the current source through the RS485 bus to dynamically adjust the heating current.

[0049] The platform uses cables as the core, and realizes electrical-thermal synergy through current source heating and voltage source excitation. Temperature sensors and partial discharge sensors collect data in real time and transmit it to the industrial computer. The control system dynamically adjusts the excitation parameters based on feedback to form a closed-loop control. The modules work together through standardized interfaces, shielded cables and synchronization mechanisms to ensure data reliability and detection accuracy.

[0050] Step S102: collecting partial discharge signals in real time through partial discharge sensors, synchronously recording temperature sensor data, and establishing a time series of temperature-partial discharge signals.

[0051] In one embodiment, the frequency band coverage of the high-frequency current transformer (HFCT) is 10kHz to 100MHz; it is connected to the acquisition card through a cable. The frequency band coverage of the ultra-high frequency antenna (UHF) is 300MHz to 3GHz, and it is connected to an oscilloscope. Distributed fiber temperature measurement (DTS): outputs multiple sets of temperature data per second. Infrared thermal imager: outputs emissivity-corrected thermal images at a frame rate of 30Hz. Acoustic emission sensor, 40dB preamplifier, 200kHz sampling rate. A three-level synchronization mechanism is used to achieve multi-sensor collaboration, and a GPS timing module (accuracy ±1μs) is deployed to provide a unified time reference for industrial computers, acquisition cards, and infrared thermal imagers through the NTP protocol. The PTP (Precision Time Protocol) master clock is embedded in the electrical-thermal joint platform, and signals are sent to each acquisition device through optical fiber to trigger the synchronous sampling of the signal acquisition card.

[0052] The acquisition card has a built-in counter, which records the counter value at each sampling and generates a timestamp in combination with the GPS time. The thermal imaging timestamp, the signal is input into the infrared thermal imager, and a frame synchronization mark is embedded in each thermal image. The partial discharge signal and the temperature data are interpolated and aligned based on the GPS timestamp, using cubic spline interpolation. The infrared thermal image and DTS data are matched by the nearest neighbor method, with an error of <50ms. It is stored in layered HDF5 format.

[0053] Step S103: extracting characteristic parameters of the partial discharge signal according to the time series of the temperature-partial discharge signal, and calculating the temperature gradient and thermal response time constant of the defect area in combination with the heat conduction model.

[0054] In one embodiment, there is noise interference in the temperature and partial discharge signals, which affects subsequent analysis. For partial discharge signals, a wavelet transform denoising method can be used. Select a suitable wavelet basis to decompose the signal, remove the high-frequency noise component by setting a threshold, and then reconstruct the signal. For the temperature signal, use a sliding average filter, set a suitable window size, and calculate the average value of the data in the window as the filtered value of the point. Ensure that the temperature signal and the partial discharge signal correspond in time. Since the sampling frequency and start-up time of different sensors may differ, the data needs to be aligned according to the timestamp. The linear interpolation method can be used to interpolate the data with a lower sampling frequency so that it matches the data with a higher sampling frequency at the time point.

[0055] Calculate the single discharge amount by integrating the partial discharge current pulse and calculate the average discharge amount. Record the phase distribution of the discharge pulse in the power frequency cycle, such as pulse rise time, polarity symmetry, etc. Temperature change rate (ΔT / Δt). Steady-state temperature value (such as target temperature 60℃-90℃).

[0056] The expression of the heat conduction model is:

[0057]

[0058] ρ is the cable material density, c is the specific heat capacity, λ is the thermal conductivity, Q Joule is the Joule heat of the conductor, Q dielectric is the dielectric loss heat, Q defect The curve discharges heat.

[0059] The finite element method (FEM) or finite difference method (FDM) is used to solve the temperature field distribution, and the boundary conditions are provided by the infrared thermal imager and DTS data.

[0060] The temperature gradient calculation calculates the spatial temperature gradient of the defect area by solving the temperature field distribution. During the specific calculation, the temperature difference between the defect center and the surrounding area is taken, and the gradient range is determined by combining the cable geometric dimensions (such as the temperature change per centimeter along the cable axis).

[0061] Calculate the thermal response time constant, Among them, m is the cable mass, c is the specific heat capacity, h is the convection heat transfer coefficient, and A is the heat dissipation area.

[0062] Step S104: Identify the defect type and locate the defect position according to the temperature gradient and thermal response time constant of the defect area.

[0063] In one embodiment, defect identification, different types of defects will cause different degrees of temperature changes, thus presenting different temperature gradients. For example, a pinpoint defect will cause a more intense local discharge, generate more heat, and make the temperature gradient in the defect area larger. Usually, a temperature gradient greater than 12°C / cm may indicate a pinpoint defect; while an air gap defect generates relatively less heat, and the temperature gradient is generally between 5-8°C / cm; due to the relatively weak discharge of a suspended defect, the temperature gradient is generally less than 3°C / cm. The thermal response time constant reflects the response speed of an object to temperature changes. Due to the strong local discharge and fast heat accumulation of a pinpoint defect, the thermal response time constant is relatively small, generally 60-80s; the thermal response time constant of an air gap defect is 100-150s; and the thermal response time constant of a suspended defect is greater than 200s. Multiple features of partial discharge signals can be used for defect identification. For example, the discharge amount (Q), when the discharge amount is greater than 200pC and the discharge phase When it is concentrated at 70°-110°, it is a needle tip defect; if the discharge amount fluctuates greatly and the discharge phase is symmetrically distributed, it is an air gap defect; when a bipolar pulse appears and the phase is irregular, it is a suspension defect. 2. Multi-feature fusion recognition method A single feature may have limitations, so the fusion analysis of multiple features such as temperature gradient, thermal response time constant and partial discharge signal characteristics can improve the accuracy of defect recognition. Machine learning algorithms such as support vector machine (SVM) and random forest can be used. Taking SVM as an example, the calculated temperature gradient, thermal response time constant, discharge amount of partial discharge signal, phase distribution and other features are used as input vectors to train the SVM model. In practical applications, the new calculation results are input into the trained SVM model, and the model will output the corresponding defect type. On the other hand, a defect knowledge base can be established to collect a large amount of case data of known defect types and establish a defect knowledge base. When performing defect recognition, the current calculation results are compared with the cases in the knowledge base to find the most similar cases, thereby determining the defect type. At the same time, with the continuous accumulation of new cases, the knowledge base is updated and improved to improve the accuracy and reliability of recognition. Defect location Positioning based on temperature distribution Abnormal temperature area judgment: According to the calculated temperature gradient and temperature distribution, find the area with abnormal temperature rise. Generally speaking, the temperature of the defective area will be significantly higher than the surrounding normal area. By analyzing the temperature data, determine the scope of the abnormal temperature area. Combined with the cable structure information, the direction of the cable, the location of the joint, etc. Since defects are usually more likely to occur in the joints of the cable, weak insulation and other parts, the defect location can be more accurately located by combining these structural information. For example, if an abnormal temperature rise is found at a certain cable joint, then there is a high probability that there is a defect at the joint. The principle of time difference positioning method (for partial discharge signals) is that when partial discharge occurs, the partial discharge signal will propagate to sensors at different locations at a certain speed. By measuring the time difference of the partial discharge signal reaching different sensors and combining the propagation speed of the signal, the distance from the discharge point to each sensor can be calculated, thereby determining the location of the discharge point. Arrange multiple partial discharge sensors along the cable and record the time when the partial discharge signal reaches each sensor. Assuming that the propagation speed of the partial discharge signal in the cable, the time difference of the signal reaching sensor A and sensor B, and the distance between sensor A and sensor B are known, the equation can be listed according to the geometric relationship to find the location of the discharge point. Infrared thermal imaging assisted positioning heat map analysis, use infrared thermal imager to scan the cable and obtain the thermal map of the cable surface. By analyzing the high temperature area in the thermal map, you can intuitively see the abnormal temperature area. Infrared thermal imaging can provide temperature distribution information on the cable surface, and combined with the positioning method based on temperature gradient and partial discharge signal, it can improve the accuracy of positioning. Spatial resolution correction, consider the spatial resolution of the infrared thermal imager and correct the positioning result. Due to the limited spatial resolution of the infrared thermal imager, there may be certain errors in the positioning result.By processing and analyzing the heat map and combining it with the results of other positioning methods, the positioning error can be corrected.

[0064] It should be noted that although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiment of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of a module or unit described above can be further divided into multiple modules or units for concretization. The components displayed as modules or units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the disclosed solution. Those of ordinary skill in the art can understand and implement it without paying creative work.

[0065] In an exemplary embodiment of the present disclosure, an electronic device is also provided, which may include a processor and a memory for storing executable instructions of the processor, wherein the processor is configured to execute the steps of the method for detecting partial discharge of cable defects based on temperature controllability in any of the above embodiments by executing the executable instructions.

[0066] It will be appreciated by those skilled in the art that various aspects of the present invention may be implemented as a system, method or program product. Therefore, various aspects of the present invention may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to herein as a "circuit", "module" or "system".

[0067] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the embodiment of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which can be a personal computer, a server or a network device, etc.) to execute the above-mentioned temperature-controllable cable defect partial discharge detection method according to the embodiment of the present disclosure.

[0068] In an exemplary embodiment of the present disclosure, a computer storage medium is further provided, on which a computer program is stored. When the program is executed by, for example, a processor, the steps of the method for detecting partial discharge of temperature-controllable cable defects described in any of the above embodiments can be implemented.

[0069] In some possible embodiments, various aspects of the present invention may also be implemented in the form of a computer program product, which includes a computer program or instructions. When the computer program product is run on a terminal device, the computer program code or instructions are used to enable the terminal device to execute the steps of various exemplary embodiments of the present invention described in the above-mentioned temperature-controllable cable defect partial discharge detection method section of this specification.

[0070] The program product described above may be written in any combination of one or more programming languages ​​to perform program code for the operation of the present invention, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device, partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0071] The computer software product may be stored in a computer storage medium, which may include a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage or any other computer-readable medium that can be used to carry or store data.

[0072] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A temperature-controllable cable defect partial discharge detection method, characterized in that: include: Construct an electric-thermal joint platform, arrange temperature sensors and partial discharge sensors in the cable defect area, and adjust the conductor current to the preset value through the through-current heating module to raise the temperature of the defect area to the target temperature; The partial discharge sensor collects partial discharge signals in real time, records temperature sensor data synchronously, and establishes a time series of temperature-partial discharge signals; According to the time series of temperature-PD signal, the characteristic parameters of PD signal are extracted, and the temperature gradient and thermal response time constant of defect area are calculated by combining with heat conduction model. According to the temperature gradient and thermal response time constant of the defect area, the defect type can be identified and the defect position can be located.

2. The temperature-controllable cable defect partial discharge detection method according to claim 1 is characterized in that: The through-flow heating module comprises: An adjustable current source, the adjustable current source being coordinated with temperature feedback closed-loop control; An infrared thermal imager is used to assist in monitoring the cable surface temperature distribution.

3. The temperature-controllable cable defect partial discharge detection method according to claim 1 is characterized in that: The partial discharge sensor comprises: A high-frequency current transformer, wherein the frequency band coverage range of the high-frequency current transformer is 10kHz to 100MHz; The UHF antenna has a frequency band coverage range of 300 MHz to 3 GHz.

4. The temperature-controllable cable defect partial discharge detection method according to claim 1 is characterized in that: The expression of the heat conduction model is: ρ is the cable material density, c is the specific heat capacity, λ is the thermal conductivity, Q Joule is the Joule heat of the conductor, Q dielectric is the dielectric loss heat, Q defect The curve discharges heat.

5. The temperature-controllable cable defect partial discharge detection method according to claim 4 is characterized in that: The expression for calculating the thermal response time constant is: Among them, m is the cable mass, c is the specific heat capacity, h is the convection heat transfer coefficient, and A is the heat dissipation area.

6. The temperature-controllable cable defect partial discharge detection method according to claim 1, characterized in that: The characteristic parameters of the partial discharge signal are discharge amount and phase distribution.

7. The temperature-controllable cable defect partial discharge detection method according to claim 1, characterized in that: The defect type is any one of a pinpoint defect, an air gap defect, a suspension defect and a surface defect.

8. The temperature-controllable cable defect partial discharge detection method according to claim 1, characterized in that: The preset value is 300A.

9. The temperature-controllable cable defect partial discharge detection method according to claim 1, characterized in that: The target temperature is 60°C-90°C.

10. The temperature-controllable cable defect partial discharge detection method according to claim 1, characterized in that: The electric-thermal combined platform also includes: A variable frequency voltage source is used to apply a variable frequency voltage during the detection process to enhance the temperature response of the defect; Acoustic emission sensor, used to assist in locating the discharge position.

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