10kV cable partial discharge signal detection and positioning method based on temperature influence

Abstract

The embodiment of the invention relates to a 10kV cable partial discharge signal detection and positioning method based on temperature influence. The method comprises the following steps: arranging an optical fiber temperature sensor and an ultrahigh frequency partial discharge sensor for a 10kV cable; performing temperature compensation on the discharge signal based on a Schottky-tunneling effect model, synchronously acquiring point wire core temperature, outer sheath temperature and the discharge signal, and calculating the wire core temperature of the 10kV cable by using a thermal circuit model; and calculating the position of a discharge point according to the propagation velocity of the discharge signal after the temperature compensation is corrected according to the core temperature of the 10kV cable. According to the invention, temperature compensation is carried out on the discharge signal based on the Schottky-tunneling effect model, the distortion of the discharge signal is eliminated, and the detection precision in a temperature-sensitive environment is improved; the signal propagation speed is corrected through the thermal circuit model, the problem that the positioning error is large under the high-temperature working condition in a traditional method is solved, and meter-scale precision positioning is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of power cables, and in particular to a method for detecting and locating partial discharge signals of 10kV cables based on temperature influence. Background Art

[0002] Partial discharge detection technology is widely used in the maintenance and fault detection of power cables to identify and locate insulation defects in cables. However, existing partial discharge detection technology faces multiple bottlenecks. Offline oscillation wave detection requires power outages, making it difficult to meet the needs of high-reliability power supply. Live detection equipment mainly relies on single-point measurement, which cannot accurately locate defects and assess their severity. More importantly, during actual operation, the core temperature of the cable can reach 90°C due to load current, while the detection temperature specified in the current standard (-10°C to 40°C) is out of line with actual operating conditions, resulting in distorted test results.

[0003] Under high temperature conditions, the Schottky effect and dielectric loss of insulating materials are exacerbated. The Schottky effect enhances thermionic emission of electrons, reducing the discharge starting voltage. Dielectric loss increases with increasing temperature, forming "temperature-loss" coupled heating, which further induces partial discharge. Traditional methods do not consider the impact of temperature on discharge signal characteristics (such as amplitude, frequency) and propagation speed, resulting in signal feature extraction deviations and time difference positioning errors (long-distance errors exceed 5%). At the same time, the defect assessment model lacks temperature parameters and cannot accurately judge the degree of insulation degradation at high temperatures, significantly increasing the risk of missed detection.

[0004] Patent CN118739184A proposes a method for automatic fault detection and repair in self-healing intelligent power lines. This method utilizes a K-Means clustering algorithm and a convolutional neural network model to accurately identify fault-prone sections and repair local lines. However, it primarily focuses on line repair and equipment status assessment, and does not adequately consider the accuracy of partial discharge detection and the effects of temperature. Patent CN119510568A discloses a method for GIS cable terminal interface defect simulation and multivariate detection. This method, through modular design and multivariate sensing monitoring technology, can effectively simulate the working conditions of cable terminals under different operating conditions. However, in actual application, this method presents certain technical challenges in the rapid and accurate positioning of partial discharge defects in long or complex lines, especially in the correction of signal propagation speed under the influence of temperature.

[0005] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0006] 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 prior art known to ordinary technicians in the field. Summary of the Invention

[0007] The purpose of the embodiments of the present disclosure is to provide a method for detecting and locating partial discharge signals of a 10kV cable based on temperature influence, thereby overcoming one or more problems caused by limitations and defects of related technologies, at least to a certain extent.

[0008] The present application provides a method for detecting and locating partial discharge signals of a 10kV cable based on temperature influence, the method comprising the following steps:

[0009] Arrange optical fiber temperature sensors and UHF partial discharge sensors on 10kV cables;

[0010] The discharge signal is temperature compensated based on the Schottky-tunneling effect model. The core temperature, outer sheath temperature, and discharge signal are collected simultaneously. The core temperature of the 10kV cable is calculated using the thermal circuit model.

[0011] The discharge point position is calculated based on the propagation velocity of the temperature-compensated discharge signal corrected according to the core temperature of the 10kV cable.

[0012] In one possible embodiment, the optical fiber temperature sensor is a distributed optical fiber sensor, which is arranged at the joints and middle sections of the 10kV cable and is used to collect the point core temperature and outer sheath temperature with an accuracy of ±0.3°C; the ultra-high frequency partial discharge sensor is arranged at both ends of the 10kV cable, and the detection frequency band of the ultra-high frequency partial discharge sensor is 300MHz-3GHz, and the sampling rate is ≥1GS / s.

[0013] In a possible implementation, the temperature compensation formula for the discharge signal based on the Schottky-tunneling effect model is:

[0014]

[0015] Where, I(T) is the discharge current at temperature T, I room is the discharge current at room temperature, k T is the temperature coefficient, T room is room temperature, E0 is activation energy, k B is the Boltzmann constant, and T is the temperature of the 10kV cable.

[0016] In a possible implementation, the thermal circuit model is:

[0017] T core =T0+I 2 R c (T)+U 2 ωC tanδ(T);

[0018] Among them, T coreis the core temperature, T0 is the outer sheath temperature of 10kV cable, I is the load current of 10kV cable, R c (T) is the core resistance that varies with temperature, U is the operating voltage of the 10 kV cable, ω is the power angular frequency, C is the capacitance of the 10 kV cable, and tanδ(T) is the dielectric loss tangent that varies with temperature.

[0019] In a possible implementation, the step of correcting the discharge signal propagation speed according to the core temperature of the 10 kV cable and calculating the discharge point position includes:

[0020] The discharge point position is calculated by the time difference and corrected speed of the UHF partial discharge sensors at both ends of the 10kV cable. The corrected discharge signal propagation speed formula is:

[0021]

[0022] where c is the speed of light in vacuum, ε r25 is the relative dielectric constant of 10kV cable insulation material at 25℃, α and b are temperature sensitivity coefficients.

[0023] In a possible implementation, the discharge point position is the distance from the discharge point to the head end of the 10 kV cable, and the calculation formula is:

[0024]

[0025] Where L is the total length of the 10kV cable, t A and t B are the times when the sensors at the beginning and end of the 10 kV cable detect the discharge signal, Δt0 is the sensor synchronization error, and v(T) is the corrected discharge signal propagation speed.

[0026] In a possible implementation, after temperature compensation is performed on the discharge signal based on the Schottky-tunneling effect model, feature extraction is performed on the temperature-compensated discharge signal.

[0027] In a possible implementation, the feature extraction of the temperature-compensated discharge signal includes extracting the time-domain discharge amount, the frequency-domain center frequency, and the temperature-energy characteristics that incorporate the temperature influence.

[0028] In a possible implementation, a three-dimensional feature vector is constructed based on the time-domain discharge amount, the frequency-domain center frequency, and the temperature-energy characteristics as an input of a support vector machine model for defect assessment.

[0029] In a possible implementation, the support vector machine model evaluation function is:

[0030]

[0031] Among them, K is the radial basis kernel function, the kernel width γ = 0.5, is the model parameter obtained by training historical data, Y is the defect level, α i and h are model parameters obtained through historical data training, y i is the defect level label of the training sample, and Y is the defect level output.

[0032] The technical solution provided by this application may have the following beneficial effects:

[0033] Through the 10kV cable partial discharge signal detection and positioning method based on temperature influence of this application, on the one hand, the discharge signal is temperature compensated based on the Schottky-tunneling effect model to eliminate the distortion of the discharge signal and improve the detection accuracy in temperature-sensitive environments; on the other hand, the signal propagation speed is corrected by the thermal circuit model, which solves the problem of large positioning error under high temperature conditions in traditional methods and achieves meter-level precision positioning.

[0034] 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 disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are incorporated into 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 drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0036] Figure 1 A schematic diagram showing the steps of a method for detecting and locating partial discharge signals of a 10 kV cable based on temperature influence in an exemplary embodiment of the present disclosure is shown;

[0037] Figure 2 A schematic flow chart of a method for detecting and locating partial discharge signals of a 10 kV cable based on temperature influence in an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0038] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will 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.

[0039] In addition, the accompanying drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. Identical reference numerals in the figures denote identical or similar parts, and thus repetitive descriptions thereof will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0040] This example embodiment provides a method for detecting and locating partial discharge signals in 10kV cables based on temperature influence. Figure 1 As shown in , the method may include the following steps:

[0041] Step S101: Arrange optical fiber temperature sensors and ultra-high frequency partial discharge sensors on the 10 kV cable.

[0042] Step S102: Temperature compensation is performed on the discharge signal based on the Schottky-tunneling effect model, and the core temperature, outer sheath temperature and discharge signal are collected synchronously, and the core temperature of the 10 kV cable is calculated using the thermal circuit model.

[0043] Step S103: Calculate the discharge point position by correcting the propagation speed of the temperature-compensated discharge signal according to the core temperature of the 10 kV cable.

[0044] Through the above method, a 10kV cable partial discharge signal detection and positioning method based on temperature influence is developed. On the one hand, the discharge signal is temperature compensated based on the Schottky-tunneling effect model to eliminate the discharge signal distortion and improve the detection accuracy in temperature-sensitive environments; on the other hand, the signal propagation speed is corrected through the thermal circuit model, which solves the problem of large positioning error under high temperature conditions in traditional methods and achieves meter-level precision positioning.

[0045] Below, we will refer to Figures 1 to 2 Each step of the above method in this exemplary embodiment is described in more detail.

[0046] Step S101: Arrange optical fiber temperature sensors and ultra-high frequency partial discharge sensors on the 10 kV cable.

[0047] Specifically, distributed fiber optic sensors (DTS) are deployed at 10kV cable joints and mid-sections. These locations are sensitive to temperature rise, with high contact resistance and concentrated electric fields. An accuracy of ±0.3°C ensures reliable temperature data and avoids deviations in subsequent thermal model calculations due to temperature measurement errors. DTS is based on the Raman scattering effect. Temperature changes cause thermal vibrations in fiber molecules, resulting in a frequency shift in the backscattered light. Temperature measurement is achieved by demodulating this offset. Its distributed characteristics enable the acquisition of temperature distribution along the entire length of the 10kV cable. Ultra-high frequency partial discharge sensors are deployed at both ends of the 10kV cable. The detection frequency band of these sensors is 300MHz-3GHz, with a sampling rate of ≥1GS / s. For long-distance cables or joints and terminals with a history of frequent failures, additional ultra-high frequency partial discharge sensors can be added at these locations to form a multi-point measurement network spanning the "head end," intermediate key nodes, and the end. Improve the probability of capturing discharge signals under complex working conditions, especially for insulation defects at joints (such as air gaps and surface discharges), and enhance the sensitivity and positioning accuracy of partial discharge detection. The detection frequency band of 300MHz-3GHz covers the ultra-high frequency signals generated by partial discharge. The discharge pulse rise time is in the nanosecond range, and the spectrum is mainly concentrated in this range. The sampling rate ≥1GS / s satisfies the Nyquist sampling theorem (avoiding aliasing), ensuring that high-frequency signal details such as the pulse leading edge and peak are fully captured, providing high-resolution data for subsequent feature extraction. Fiber optic temperature sensors and ultra-high frequency partial discharge sensors need to be spatially coordinated to ensure a one-to-one correspondence between the temperature data and the discharge signal collection location. For example, arranging both sensors simultaneously at the joint can avoid data deviation caused by temporal and spatial misalignment.

[0048] Step S102: Temperature compensation is performed on the discharge signal based on the Schottky-tunneling effect model, and the core temperature, outer sheath temperature and discharge signal are collected synchronously, and the core temperature of the 10 kV cable is calculated using the thermal circuit model.

[0049] Specifically, the temperature compensation formula for the discharge signal based on the Schottky-tunneling effect model is:

[0050]

[0051] Where, I(T) is the discharge current at temperature T, I room is the discharge current at room temperature, k T is the temperature coefficient, T room is room temperature, E0 is activation energy, k B is the Boltzmann constant, and T is the temperature of the 10kV cable.

[0052] In the Schottky effect, the current of electrons passing through the insulating material-electrode interface barrier is exponentially related to temperature. Combined with the linear temperature coefficient of the material conductivity, the discharge current I at room temperature can be calculated by this formula.room Correct the current I(T) to the actual temperature T to avoid the distortion of the discharge signal amplitude caused by temperature increase.

[0053] The core temperature, outer sheath temperature and discharge signal of the point were collected synchronously, and the core temperature of the 10kV cable was calculated using the thermal circuit model. The thermal circuit model is:

[0054] T core =T0+I 2 R c (T)+U 2 ωC tanδ(T);

[0055] Among them, T core is the core temperature, T0 is the outer sheath temperature of 10kV cable, I is the load current of 10kV cable, R c (T) is the core resistance that varies with temperature, U is the operating voltage of the 10 kV cable, ω is the power angular frequency, C is the capacitance of the 10 kV cable, and tanδ(T) is the dielectric loss tangent that varies with temperature.

[0056] It is important to understand that the core temperature of a 10kV cable is calculated as the core parameter of the internal temperature distribution, which is used to correct the signal propagation speed and defect assessment. The thermal circuit model considers two heating mechanisms. One is Joule heating, where the load current I passes through the core resistance R c (T) Heat generated I 2 R c , R c (T) increases linearly with increasing temperature; the other is dielectric loss heating. Under the action of voltage U, the dielectric loss tanδ of the insulating material increases with increasing temperature, generating heat ωC tanδ(T).

[0057] The outer sheath temperature T0 is used as the heat dissipation boundary condition, and the core temperature is obtained through iterative solution, providing a key input for subsequent temperature-related calculations.

[0058] The discharge signal propagation velocity is corrected based on the core temperature of the 10kV cable. The steps for calculating the discharge point location include:

[0059] The discharge point position is calculated by the time difference and corrected speed of the UHF partial discharge sensors at both ends of the 10kV cable. The corrected discharge signal propagation speed formula is:

[0060]

[0061] where c is the speed of light in vacuum, ε r25 is the relative dielectric constant of 10kV cable insulation material at 25℃, α and b are temperature sensitivity coefficients.

[0062] Correct the effect of temperature on signal propagation speed and solve the problem of dielectric constant ε of insulating material r Positioning error caused by temperature change. The propagation speed of the original signal in the 10kV cable ε r It increases with increasing temperature and is described by polynomial fitting. r The temperature characteristics of the velocity v(T) are calculated. Taking 25°C as the benchmark, the dielectric constant at the actual temperature T is substituted into the formula to obtain the corrected velocity v(T). This ensures that the velocity parameters during time-of-day positioning are consistent with the actual working conditions and reduces long-distance positioning errors (the traditional uncorrected error is >5%, while the corrected error is <1%).

[0063] The discharge point position is the distance from the discharge point to the head end of the 10kV cable, and the calculation formula is:

[0064]

[0065] Where L is the total length of the 10kV cable, t A and t B The time when the discharge signal is detected by the sensors at the head and end of the 10kV cable is Δt0, which is the initial time difference, and v(T) which is the corrected propagation speed of the discharge signal. Based on the time difference positioning principle and the corrected propagation speed, the exact position of the discharge point from the head end is calculated. Assuming that the distance between the discharge point and the head end is x and Lx, the time when the signal reaches the head end is t. A =x / v(T), arrival time t B =(Lx) / v(T), time difference Δt=t B -t A =(L-2x) / v(T), and we can get In the formula, Δt0 is the sensor synchronization error, which is measured in advance through calibration. After deduction, it ensures that the time difference is determined only by the position of the discharge point. The arrival time of the signals synchronously collected at both ends of the 10kV cable is combined with the correction speed to achieve meter-level positioning accuracy.

[0066] In one embodiment, after temperature compensation, the time-domain discharge amount, frequency-domain center frequency, and temperature-energy characteristics of the fusion temperature effect are extracted.

[0067] The time domain discharge amount is calculated by integrating the temperature compensated discharge signal in the time domain to calculate the charge released by a single discharge. The calculation formula is:

[0068]

[0069] Among them, the integral of the discharge current i(t) on the time axis is the charge q, t s and t eThrough signal threshold detection, the starting and ending points are determined as exceeding three times the noise level. The larger the discharge amount, the more serious the insulation defect. For example, if the corona discharge amount is small, the creeping discharge amount is large. Combined with the temperature-compensated current signal, it can eliminate temperature interference on the amplitude and accurately reflect the true state of the defect.

[0070] The frequency domain center frequency is calculated by multiplying each frequency by its corresponding energy in the frequency range of 10kHz to 2GHz, and then dividing it by the total energy of all frequency components. The resulting frequency domain center frequency is calculated as follows:

[0071]

[0072] Among them, the frequency domain center frequency represents the concentrated frequency of the discharge signal energy in the frequency domain, reflecting the geometric dimensions of the discharge channel and the characteristics of the insulating material. For example, a narrow discharge channel produces a high-frequency signal, while a wide channel has more low-frequency components. The frequency domain amplitude F(f) is obtained by performing fast Fourier transform (FFT) on the discharge signal, |F(f)| 2 The center frequency is calculated by taking the energy of each frequency component and weighted averaging it. High-frequency center frequencies greater than 1 GHz correspond to pinpoint defects, while low-frequency center frequencies less than 500 MHz correspond to air gap defects. Combined with temperature, this allows for differentiation of defect characteristics under different operating conditions.

[0073] The temperature-energy characteristics are normalized to compare the discharge amount q at the current temperature T with the room temperature T room Discharge capacity q room In contrast, combined with the temperature difference (TT room ), and obtain the dimensionless characteristic E T . When E T When it is >0, it indicates that the temperature rise leads to a relative increase in discharge energy, which may indicate that the thermal aging of the insulation material is aggravated and the development of defects is accelerated. The calculation formula of temperature-energy characteristics is:

[0074]

[0075] Where q is the time domain discharge at the current temperature, T is the 10kV cable temperature, and q room is the time domain discharge at room temperature, T room The effect of temperature change on discharge energy is quantified to reflect the "temperature-discharge" coupling effect. For example, the discharge amount of the same defect may increase at high temperature.

[0076] According to the time domain discharge, frequency domain center frequency and temperature-energy characteristics, a three-dimensional feature vector is constructed as the input of the support vector machine model for defect assessment.

[0077] Specifically, a support vector machine (SVM) model was used to assess the grade of 10kV cable insulation defects by integrating three-dimensional feature vectors influenced by temperature. Traditional methods fail to consider the impact of temperature on discharge characteristics, resulting in distorted defect assessment at high temperatures. By introducing temperature-energy features, combining time-domain discharge volume and frequency-domain center frequency, a feature space incorporating temperature coupling effects was constructed. This model can accurately identify the degree of insulation degradation under different temperature conditions, addressing the problem of missed detection in high-temperature environments.

[0078] Multi-classification SVM is used, and the kernel function is the radial basis kernel function (RBF), which can effectively process nonlinear separable data and adapt to the complex mapping relationship between discharge characteristics and defect levels. The evaluation function is:

[0079] Among them, q is the time domain discharge, f c is the center frequency in the frequency domain, E T is the temperature-energy characteristic, T core is the core temperature, K is the radial basis kernel function, kernel width γ=0.5, is the model parameter obtained by historical data training, Y is the defect level, α i and h are model parameters obtained through historical data training, y i is the defect grade label of the training sample, and Y is the defect grade output.

[0080] K(x i ,x) is the RBF kernel function, which calculates the sample x i Similarity with the input vector x, y i is the defect grade label of the training sample, such as 0-normal, 1-minor defect, 2-serious defect, and Y is the output defect grade.

[0081] Sample labeling: historical data are labeled according to defect levels, such as normal, partial discharge, and insulation breakdown, to form a training set {(x i ,y i )}, where x i =[q i ,f ci ,E Ti ,],y i The parameter optimization uses the cross-validation method to adjust the RBF kernel width γ and the penalty factor z to minimize the classification error and avoid overfitting. During the training process, the maximum margin classification hyperplane is solved by quadratic programming to determine the support vector and parameter α. i and h, so that the model can best distinguish different defect levels in the feature space. Defect assessment input is the three-dimensional feature vector [q,f c ,E T], using the trained SVM model to calculate the classification function value. The defect grade Y is output based on the sign function sgn, enabling real-time assessment of the insulation condition of 10kV cables, such as identifying defect development caused by increased dielectric loss at high temperatures.

[0082] It should be noted that those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A method for detecting and locating partial discharge signals of 10kV cables based on temperature influence, characterized in that: The following steps are involved: Arrange optical fiber temperature sensors and UHF partial discharge sensors on 10kV cables; The discharge signal is temperature compensated based on the Schottky-tunneling effect model. The core temperature, outer sheath temperature, and discharge signal are collected simultaneously. The core temperature of the 10kV cable is calculated using the thermal circuit model. The discharge point position is calculated based on the propagation velocity of the temperature-compensated discharge signal corrected according to the core temperature of the 10kV cable.

2. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 1, characterized in that: The optical fiber temperature sensor is a distributed optical fiber sensor, which is arranged at the joints and middle sections of the 10kV cable and is used to collect the point core temperature and outer sheath temperature with an accuracy of ±0.3°C. The ultra-high frequency partial discharge sensor is arranged at both ends of the 10kV cable. The detection frequency band of the ultra-high frequency partial discharge sensor is 300MHz-3GHz, and the sampling rate is ≥1GS / s.

3. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 1, characterized in that: The temperature compensation formula for the discharge signal based on the Schottky-tunneling effect model is: Where, I(T) is the discharge current at temperature T, I room is the discharge current at room temperature, k T is the temperature coefficient, T room is room temperature, E0 is activation energy, k B is the Boltzmann constant, and T is the temperature of the cable.

4. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 3 is characterized in that: The thermal circuit model is: T core =T0+I 2 R c (T)+U 2 ωC tanδ(T); Among them, T core is the core temperature, T0 is the outer sheath temperature of 10kV cable, I is the load current of 10kV cable, R c (T) is the core resistance that varies with temperature, U is the operating voltage of the 10 kV cable, ω is the power angular frequency, C is the capacitance of the 10 kV cable, and tanδ(T) is the dielectric loss tangent that varies with temperature.

5. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 4, characterized in that: The step of correcting the discharge signal propagation speed according to the core temperature of the 10kV cable and calculating the discharge point position includes: The discharge point position is calculated by the time difference and corrected speed of the UHF partial discharge sensors at both ends of the 10kV cable. The corrected discharge signal propagation speed formula is: where c is the speed of light in vacuum, ε r25 is the relative dielectric constant of 10kV cable insulation material at 25℃, α and b are temperature sensitivity coefficients.

6. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 5, characterized in that: The discharge point position is the distance from the discharge point to the head end of the 10kV cable, and the calculation formula is: Where L is the total length of the 10kV cable, t A and t B are the times when the sensors at the beginning and end of the 10 kV cable detect the discharge signal, Δt0 is the sensor synchronization error, and v(T) is the corrected discharge signal propagation speed.

7. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 1, characterized in that: After temperature compensation is performed on the discharge signal based on the Schottky-tunneling effect model, feature extraction is performed on the temperature-compensated discharge signal.

8. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 7, characterized in that: The feature extraction of the temperature-compensated discharge signal includes extracting the time-domain discharge amount, the frequency-domain center frequency, and the temperature-energy characteristics that are influenced by the fusion temperature.

9. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 8, characterized in that: According to the time domain discharge amount, frequency domain center frequency and temperature-energy characteristics, a three-dimensional feature vector is constructed as the input of the support vector machine model for defect assessment.

10. The method for detecting and locating 10kV cable partial discharge signals based on temperature influence according to claim 9, characterized in that: The support vector machine model evaluation function is: Among them, K is the radial basis kernel function, the kernel width γ = 0.5, is the model parameter obtained by training historical data, Y is the defect level, α i and h are model parameters obtained through historical data training, y i is the defect grade label of the training sample, and Y is the defect grade output.

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