Cable terminal temperature monitoring method, system and equipment based on capacitive coupling signal and medium

Abstract

The invention discloses a cable terminal temperature monitoring method, system and device based on capacitive coupling signals and a medium, and belongs to the technical field of power system monitoring technologies, and the method comprises the steps: collecting a voltage signal of a low-voltage side of a cable terminal to form first electrical data; constructing a first thermal-electric coupling model, and converting the first electrical data into first temperature data; comparing the first temperature data of the plurality of cable terminals to obtain a relative ratio, and determining a first abnormal state based on a first preset threshold; applying disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model; and combining the relative ratio with the second thermal-electric coupling model, and outputting early warning information. According to the method, the cable terminal low-voltage side voltage signals are collected, the thermal-electric coupling model is constructed to invert the initial temperature estimated value, external factor interference is eliminated by combining multi-terminal signal comparison, Gaussian distribution disturbance is introduced to correct model parameter deviation, system adaptability and robustness are enhanced, and early overheating fault accurate early warning is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system monitoring technology, and in particular to a cable terminal temperature monitoring method, system, equipment and medium based on capacitive coupling signals. Background Art

[0002] With the continuous development of power systems, cable terminals, as key nodes in power transmission, have a direct impact on the safety and reliability of the entire power grid. However, in actual operation, cable terminals often experience local overheating due to poor contact, uneven current carrying, or changes in the external environment. This can lead to accelerated equipment aging, reduced insulation performance, and even serious power accidents.

[0003] Existing cable terminal temperature monitoring technologies mainly rely on contact or non-contact temperature sensors. Although these methods can provide certain temperature monitoring capabilities, they have many limitations in practical applications: (1) High cost: Traditional methods require additional sensor hardware, which is expensive to install and maintain, especially for the renovation of old equipment. (2) Sensitivity to external fluctuations: External factors such as grid fluctuations and load changes can cause voltage changes, and existing technologies have difficulty distinguishing the relationship between these external fluctuations and actual temperature changes, resulting in false alarms or missed alarms. (3) Single-point monitoring limitations: Existing technologies usually rely on single-point sensors for temperature monitoring and lack multi-point comparative analysis capabilities, making it difficult to detect early overheating faults in a timely manner. (4) Insufficient early warning capabilities: Existing methods are less sensitive to slowly rising temperature faults, making it difficult to achieve early warnings, which may cause the fault to gradually worsen or even cause serious accidents. Summary of the Invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: how to realize online monitoring, abnormal warning and multi-point comparative analysis of cable terminal temperature through capacitive coupling signal and thermal-electric coupling modeling, while eliminating external fluctuation interference and improving system reliability and deployment convenience.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a cable terminal temperature monitoring method based on capacitive coupling signal, which comprises the following steps:

[0007] collecting a voltage signal on the low-voltage side of a cable terminal to form first electrical data;

[0008] constructing a first thermal-electric coupling model to convert the first electrical data into first temperature data;

[0009] Comparing and analyzing the first temperature data of a plurality of cable terminals to obtain a relative ratio, and determining a first abnormal state based on a first preset threshold;

[0010] applying a disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model;

[0011] The relative ratio is combined with the second thermal-electric coupling model to generate a second abnormal state and output warning information.

[0012] As a preferred solution of the cable terminal temperature monitoring method based on capacitive coupling signal described in the present invention, collecting the low-voltage side voltage signal of the cable terminal to form the first electrical data includes:

[0013] Obtaining a voltage signal outputted from the low-voltage side of the cable terminal;

[0014] Form electrical data containing time series characteristics.

[0015] As a preferred solution of the cable terminal temperature monitoring method based on capacitive coupling signal according to the present invention, the step of constructing a first thermal-electric coupling model and converting the first electrical data into first temperature data includes:

[0016] Establish the relationship between temperature change rate and current, thermal resistance and ambient temperature;

[0017] The nonlinear relationship between the dielectric constant of the insulating medium and the material temperature is decomposed into a polynomial or exponential function form, namely the first thermal-electric coupling model.

[0018] The beneficial effects of this preferred technical solution are: temperature monitoring based on the principle of capacitive coupling avoids direct contact with the device surface, eliminates problems such as surface contamination and contact resistance changes, thereby improving the long-term reliability of the system and avoiding the performance degradation that may be caused by traditional temperature sensors.

[0019] As a preferred embodiment of the cable terminal temperature monitoring method based on capacitive coupling signals described in the present invention, wherein: the first temperature data of the plurality of cable terminals are compared and analyzed to obtain a relative ratio, and determining the first abnormal state based on a first preset threshold includes:

[0020] Collect low-voltage side voltage signals of multiple cable terminals and calculate the relative ratio of the low-voltage side voltage signal of each cable terminal;

[0021] Calculating the mean value of the voltage signal as a reference;

[0022] The equivalent temperature difference is inferred through coupling calculation of the capacitance voltage division formula and the dielectric constant-temperature function, and the first abnormal state is determined in combination with the first preset threshold.

[0023] The beneficial effect of this preferred technical solution is that: through the multi-point comparison algorithm, the voltage signals of different cable terminals in the same electrical equipment are compared with the average value of all terminals, thereby eliminating the influence of external fluctuations.

[0024] As a preferred solution of the cable terminal temperature monitoring method based on capacitive coupling signal described in the present invention, the coupling calculation of the capacitance voltage divider formula and the dielectric constant-temperature function includes:

[0025] Obtain voltage data at different temperatures through controlled variable experiments;

[0026] The corresponding curves of voltage and temperature change are fitted to form a mapping relationship for inverse temperature difference.

[0027] As a preferred solution of the cable terminal temperature monitoring method based on capacitive coupling signals described in the present invention, wherein: applying a disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model includes:

[0028] Set tolerance ranges for copper conductor resistance, resin thermal resistance, and initial temperature parameters;

[0029] The copper conductor resistance, resin thermal resistance and initial temperature parameters are randomly sampled and simulated multiple times, and the voltage-temperature curve is fitted and corrected by using the Monte Carlo simulation method.

[0030] The beneficial effects of this preferred technical solution are: correcting the model parameter deviation and enhancing the adaptability and robustness of the system.

[0031] This is a preferred embodiment of the cable terminal temperature monitoring method based on capacitive coupling signals described in the present invention, wherein: combining the relative ratio with the second thermal-electric coupling model to generate a second abnormal state and outputting warning information includes:

[0032] Set up abnormality determination strategies for multiple consecutive cycles;

[0033] If the second preset threshold value is exceeded for multiple consecutive periods, an early warning signal is output.

[0034] Another object of the present invention is to provide a system for improving the efficiency of short-term high-frequency energy storage.

[0035] To solve the above technical problems, the present invention provides the following technical solutions: A system for improving the efficiency of short-term high-frequency energy storage, comprising: an electrical data acquisition module for acquiring a voltage signal on the low-voltage side of a cable terminal and forming first electrical data;

[0036] a thermoelectric coupling modeling module, configured to construct a first thermoelectric coupling model based on the first electrical data and convert a voltage signal into first temperature data;

[0037] a multi-point comparison and analysis module, configured to compare and analyze first temperature data of a plurality of cable terminals, calculate a relative ratio, and determine a first abnormal state based on a first preset threshold;

[0038] a model parameter correction module, configured to apply a disturbance to the first thermal-electric coupling model to generate a second thermal-electric coupling model to correct parameter deviations;

[0039] The fault warning output module is used to generate a second abnormal state by combining the relative ratio with a second thermal-electric coupling model, and output graded warning information.

[0040] The present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the cable terminal temperature monitoring method based on capacitive coupling signals are implemented.

[0041] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the cable terminal temperature monitoring method based on capacitive coupling signals are implemented.

[0042] The beneficial effects of the present invention are as follows: by collecting the voltage signal on the low-voltage side of the cable terminal and combining it with the principle of capacitive coupling, online temperature monitoring without the need for additional sensors is achieved; a thermal-electric coupling model is constructed based on electrical data, and the initial temperature estimate is inverted and inferred to achieve accurate identification and dynamic tracking of temperature changes inside the cable terminal; a multi-terminal signal comparison algorithm is used to calculate relative ratios, effectively eliminating interference from external factors such as grid fluctuations and load changes, significantly improving the accuracy of abnormal temperature rise identification; a Gaussian distribution perturbation is introduced into the thermal-electric coupling model to correct the model parameter deviation, enhancing the adaptability and robustness of the system; combined with the corrected model, fault warning information is output, providing a hierarchical alarm mechanism, and achieving accurate early warning of overheating faults. This preferred technical solution not only significantly reduces installation and operation and maintenance costs, avoids economic losses caused by equipment modification and downtime, but also improves the reliability and stability of the system in complex environments such as high temperature, high humidity, and electromagnetic interference through non-contact temperature monitoring. At the same time, the application of the multi-point comparison algorithm eliminates the false alarm problem caused by external fluctuations in traditional methods, significantly improving the stability and accuracy of temperature monitoring. In addition, the solution has real-time monitoring and intelligent fault warning capabilities, which can effectively solve the timeliness and accuracy issues of temperature monitoring in the power system. It is suitable for the transformation of old equipment and intelligent operation and maintenance scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 The present invention provides a schematic diagram of the overall process of a cable terminal temperature monitoring method based on capacitive coupling signals according to an embodiment of the present invention.

[0045] Figure 2 A schematic structural diagram of a cable terminal temperature monitoring method based on capacitive coupling signals provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0046] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0047] Example 1, with reference to Figure 1 , which is the first embodiment of the present invention, provides a cable terminal temperature monitoring method based on capacitive coupling signals, comprising:

[0048] S1: collecting the voltage signal on the low-voltage side of the cable terminal to form the first electrical data;

[0049] S2: constructing a first thermal-electric coupling model to convert the first electrical data into first temperature data;

[0050] S3: Comparing and analyzing the first temperature data of the plurality of cable terminals to obtain a relative ratio, and determining a first abnormal state based on a first preset threshold;

[0051] S4: applying a disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model;

[0052] S5: Combining the relative ratio with the second thermal-electric coupling model to generate a second abnormal state and outputting warning information.

[0053] It should be noted that during operation, cable terminals often experience local overheating due to poor contact, uneven current carrying, or changes in the external environment, which in turn accelerates equipment aging, degrades insulation performance, and even causes serious accidents. Traditional temperature monitoring methods rely on contact or non-contact sensors, which have problems such as high cost, complex installation, and poor reliability. Especially in harsh environments such as high temperature, high humidity, and electromagnetic interference, sensor performance is prone to degradation or failure. In addition, existing technologies are difficult to effectively deal with voltage fluctuations caused by external factors such as grid fluctuations and load changes, which may lead to inaccurate temperature monitoring or false alarms, affecting the safety and stability of the power system. Therefore, there is a need for a temperature monitoring method that is low-cost, does not require additional sensors, is easy to deploy, and can eliminate external interference to meet the power system's requirements for high-precision and high-stability temperature monitoring.

[0054] Therefore, through the technical solutions of S1 to S5, a cable terminal temperature monitoring method based on capacitive coupling signals is constructed. The voltage signal on the low-voltage side of the cable terminal is collected to form electrical data, which provides a basis for temperature inversion; a thermal-electric coupling model is constructed based on the electrical data, and the initial temperature estimate is calculated using the characteristic that the dielectric constant of the insulating material changes with temperature, so as to preliminarily identify the internal temperature change; by comparing the initial temperature estimate with multiple terminal signals and calculating the relative ratio, external fluctuation interference is eliminated and abnormal temperature rise is accurately identified; Gaussian distribution perturbation is introduced into the thermal-electric coupling model to correct parameter deviations and improve system adaptability and robustness; fault warning information is output in combination with the corrected model to realize intelligent warning of early overheating faults. The present invention improves the reliability and accuracy of monitoring, solves the stability and accuracy problems of temperature monitoring in power systems, and provides technical guarantees for the safe operation of cable terminals.

[0055] Example 2, reference Figure 1 and Figure 2 , which is the second embodiment of the present invention, provides a cable terminal temperature monitoring method based on capacitive coupling signals.

[0056] In the implementation of this application, collecting the voltage signal on the low-voltage side of the cable terminal to form the first electrical data includes the following steps A1-A2:

[0057] A1: Get the voltage signal output from the low-voltage side of the cable terminal;

[0058] A2: forming first electrical data including timing characteristics.

[0059] Specifically, such as Figure 2As shown, in step A1, the conductor copper bolt in the cable terminal serves as the main current carrier, and the temperature first rises under the action of the load current, forming a temperature starting point T1. The heat is radially conducted to the middle part T2 and the outer surface T3 of the coupling electrode layer, forming a temperature gradient that decreases from the inside to the outside. The temperature response area monitored by the present invention is right in between, and the dielectric constant of its insulating medium is highly sensitive to temperature changes, which in turn affects the capacitance change of the coupling capacitor. Under the system capacitor voltage divider structure, the output voltage will change slightly with the temperature rise. By collecting the voltage signal, the temperature can be inferred, and the local overheating fault can be effectively identified, and non-contact online monitoring of the temperature status of the cable terminal can be achieved;

[0060] In step A2, the high-voltage side capacitor is composed of the insulating material between the copper bolt and the coupling electrode, which is represented by the temperature-dependent capacitor C1(T); the low-voltage side is the reference capacitor C2, which is usually an internal integrated stabilizing capacitor. Since C1(T) depends on the dielectric constant ε of the insulating medium, r (T), and this parameter changes nonlinearly with temperature, especially near the glass transition temperature T g Therefore, temperature changes will cause measurable changes in the output voltage through the equivalent capacitance. The specific expression is:

[0061]

[0062] Where A is the electrode area and d is the plate spacing, which are usually fixed structural parameters.

[0063] The first electrical data refers to the most basic core parameters in the electrical system, such as voltage, current, power, frequency, etc., which are used to directly describe the operating status of the circuit or equipment.

[0064] In another embodiment, the first electrical data may also be power quality parameters, equipment status parameters, dynamic characteristics, and environment-related data, thereby covering multi-dimensional analysis requirements from basic monitoring to fault diagnosis and energy efficiency optimization.

[0065] In an embodiment of the present invention, constructing a first thermal-electric coupling model and converting first electrical data into first temperature data includes the following steps B1-B2:

[0066] B1: Establish the relationship between temperature change rate and current, thermal resistance and ambient temperature;

[0067] B2: Decompose the nonlinear relationship between the dielectric constant of the insulating medium and the material temperature into a polynomial or exponential function form, that is, the first thermal-electric coupling model.

[0068] The first temperature data refers to a core parameter obtained by direct measurement or model calculation that reflects the thermal state of the electrical equipment or system, such as cable conductor temperature, insulation layer temperature, or equipment surface temperature.

[0069] Specifically, in step B1, the relationship between the temperature change rate and the current, thermal resistance, and ambient temperature is established. By establishing a thermal balance equation, the dynamic balance between the Joule heat caused by the current and the heat dissipation is described. The formula of the thermal balance equation is:

[0070]

[0071] Among them, C th Represents heat capacity, R th Represents the equivalent thermal resistance, T ambient is the ambient temperature, dT represents the change in temperature. In this equation, dT represents the change in temperature per unit time, and dt represents the change in time. Is the temperature change rate, which indicates the rate of change of temperature per unit time, I 2 (t) represents the square of the current. Here I(t) is the current that changes with time, I 2 (t) is the square value of the current, which represents the Joule heat generated when the current passes through the cable terminal. The Joule heat is proportional to the square of the current, so its influence on temperature change is very critical. T(t) is the medium temperature at time t, T(t)-T ambient Overall represents the temperature change due to heat generation and heat transfer.

[0072] In step B2, the relationship between the dielectric constant of the insulating material and the temperature is:

[0073] ε r (T) = ε0·(1+α·ΔT+β·ΔT 2 );

[0074] Among them, ε r (T) represents the dielectric constant of the insulating material at temperature T, ε0 is the dielectric constant at the reference temperature, α and β are the material characteristic fitting coefficients, ΔT = T-T0 represents the temperature change, and ΔT is the difference between the current temperature and the reference temperature.

[0075] In an optional implementation, the construction of the first thermal-electrical coupling model can also incorporate multi-physics coupling analysis, integrating physical processes such as heat conduction, capacitance changes, and material properties. Finite element methods are used to discretize the cable terminal geometry, simulate the changes in capacitance coupling signals under different temperature gradients, and establish a precise mapping relationship between temperature and capacitance response, such as the impact of thermal stress on the dielectric constant of the insulation material and localized heating caused by uneven current density distribution, to improve the accuracy and reliability of the model.

[0076] In another optional embodiment, the first thermal-electric coupling model can also be constructed by training a large amount of measured temperature-voltage data using a machine learning algorithm to establish a nonlinear black-box model. Cable terminal temperature and low-voltage side capacitor coupling voltage signals under different operating conditions are collected to construct a training dataset. This is then fitted using a machine learning model, such as a neural network, to learn the inherent patterns between temperature changes and capacitor responses.

[0077] In the implementation of the present application, first temperature data of multiple cable terminals are compared and analyzed to obtain a relative ratio, and a first abnormal state is determined based on a first preset threshold, including the following steps C1-C3:

[0078] C1: Collect low-voltage side voltage signals from multiple cable terminals and calculate the relative ratio of the low-voltage side voltage signals from each cable terminal;

[0079] C2: Calculate the mean value of the voltage signal as a benchmark;

[0080] C3: The equivalent temperature difference is inferred by coupling the capacitance voltage divider formula with the dielectric constant-temperature function, and the first abnormal state is determined in combination with the first preset threshold.

[0081] Among them, the first preset threshold refers to the critical value pre-set in the electrical monitoring system for determining whether the equipment or parameters are abnormal; the first abnormal state refers to the state of deviation from normal operating conditions that is first detected in the electrical system through the preset threshold or model analysis.

[0082] Specifically, in step C1, it is assumed that there are i cable terminals in the system, and their low-voltage output voltage signals {U1, U2, ..., U i}, the sampling period can be set to 1min~5min.

[0083] In step C2, the formula for calculating the voltage mean is:

[0084]

[0085] This formula is used as a reference for subsequent ratios, where n is the number of cable terminals and U is i is the low-voltage side voltage at the i-th cable terminal.

[0086] The relative ratio judgment formula is:

[0087]

[0088] In this formula, It represents a ratio parameter, which directly reflects the capacitance increment, that is, it indirectly corresponds to the temperature increment.

[0089] In step C3, through the experimentally calibrated voltage-temperature curve, the change in capacitance is ultimately transmitted to the low-voltage output voltage U2 through the series capacitor voltage division principle. The overall mathematical relationship can be expressed as:

[0090]

[0091] Among them, C2 is the secondary side reference capacitor, which is temperature stable and its change can be ignored; U2(T) represents the low voltage output voltage at time T, U HV It is the voltage at the high voltage terminal, and C1(T) is the capacitance at time T. It can be seen that the change in temperature eventually leads to a small but measurable change in the output voltage U2. Especially in T→T g interval, T represents temperature, T g represents the glass transition temperature, due to ε r The nonlinear amplification characteristics of the curve significantly increase the sensitivity of U2 to temperature changes, which is conducive to early detection of abnormal temperature rise. Substitute the expression of C1(T) into the voltage formula:

[0092]

[0093] Where A is the electrode area, d is the plate distance, C2 is the secondary side reference capacitance, U HV It represents the high voltage terminal voltage, U2 is the low voltage output voltage, and is the dielectric constant at the reference temperature.

[0094] Substitute the expression of C1(T) into the temperature-dielectric constant relationship:

[0095]

[0096] Therefore, after solving ΔT and adding the reference temperature T0, the monitoring point temperature T can be obtained.

[0097] The expression of temperature change and capacitance change is:

[0098]

[0099] Where ε is the dielectric constant of the insulating material, which changes nonlinearly with temperature; A is the electrode area; and d is the distance between the electrodes.

[0100] The voltage change expression is:

[0101]

[0102] Among them, U in is the input voltage.

[0103] From this, the equivalent temperature difference ΔT can be deduced i , the voltage-temperature curve corresponding to the experimental calibration is used to infer the equivalent temperature difference ΔT i, and further obtain if ΔT i >θ, where the threshold can be set to empirical values ​​such as 5℃, 10℃, etc., k i If the terminal is in the range, it is determined that there is a risk of overheating.

[0104] In the implementation of this application, the coupled calculation of the capacitance voltage divider formula and the dielectric constant-temperature function includes the following steps D1 and D2:

[0105] D1: Obtain voltage data at different temperatures through controlled variable experiments;

[0106] D2: Fit the corresponding curve of voltage and temperature change to form a mapping relationship for inverse temperature difference.

[0107] In an optional embodiment, voltage data at different temperatures are obtained by building a test platform that simulates the cable terminal in a laboratory environment, using precise temperature control equipment and high-precision voltage measuring instruments, gradually changing the temperature of the cable terminal, and performing multiple measurements at each set temperature point to obtain stable voltage data.

[0108] In another alternative implementation, voltage data at different temperatures can be obtained by utilizing field-operated cable terminals in conjunction with distributed temperature sensors (DTS) or other environmental monitoring equipment to monitor temperature changes at the cable terminals in real time and simultaneously record the corresponding voltage signals. This approach allows for the acquisition of temperature-voltage data under actual operating conditions, including varying loads, ambient temperature variations, and other potential interference factors.

[0109] In the implementation of the present application, applying a disturbance to the first thermo-electric coupling model to form a second thermo-electric coupling model includes the following steps E1 and E2:

[0110] E1: Set tolerance range for copper conductor resistance, resin thermal resistance and initial temperature parameters;

[0111] E2: The copper conductor resistance, resin thermal resistance and initial temperature parameters were randomly sampled and simulated multiple times, and the voltage-temperature curve was fitted and corrected using the Monte Carlo simulation method.

[0112] The second thermal-electric coupling model is an advanced model that introduces dynamic disturbance or multi-physical field coupling based on the first thermal-electric coupling model and is verified through experiments or iterative optimization through simulation.

[0113] Specifically, in step E1, a certain range of tolerance (e.g., ±5%) is set for the copper conductor resistance R, the resin thermal resistance Rth, the initial temperature condition T0, etc.;

[0114] In step E2, the voltage-temperature curve is fitted and corrected by the Monte Carlo simulation method to enhance the adaptability and robustness of the model to different batches of equipment.

[0115] In the implementation of this application, the relative ratio is combined with the second thermal-electric coupling model to generate a second abnormal state, and outputting warning information includes the following steps F1-F2:

[0116] F1: Set the abnormality determination strategy for multiple consecutive cycles;

[0117] F2: If the second preset threshold is exceeded for multiple consecutive cycles, an early warning signal is output.

[0118] Among them, the second abnormal state is a more complex and serious fault state in the electrical system that is further evolved or compounded based on the first abnormal state, multi-parameter linkage abnormality or long-term cumulative effect.

[0119] Specifically, in step F2, U i Corresponding to the experimentally calibrated voltage-temperature curve, the temperature calculation formula derived by combining the relationship between temperature and capacitance and the capacitor voltage divider relationship is used to infer the equivalent temperature difference ΔT. i , and further obtain if ΔT i >θ, where the threshold θ can be set to empirical values ​​such as 5℃, 10℃, etc., κ i The temperature difference judgment threshold in the present invention is preferably set to 5°C. This setting is based on the dielectric response characteristics of commonly used insulation materials within the operating temperature range, combined with engineering experience in early overheating identification in power distribution systems. It should be noted that this threshold can be adjusted based on the specific device type, operating environment, and material parameters. For example, it can also be set to 3°C, 7°C, or 10°C without affecting the basic principles and technical effects of the present invention.

[0120] Example 3 is the third embodiment of the present invention. It is different from the previous two embodiments in that if the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0121] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0122] More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0123] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0124] Embodiment 4 is the fourth embodiment of the present invention, which provides a system for monitoring cable terminal temperature based on capacitive coupling signals, including an electrical data acquisition module for acquiring a voltage signal on the low-voltage side of the cable terminal and forming first electrical data;

[0125] a thermoelectric coupling modeling module, configured to construct a first thermoelectric coupling model based on the first electrical data and convert the voltage signal into first temperature data;

[0126] a multi-point comparison and analysis module, configured to compare and analyze first temperature data of a plurality of cable terminals, calculate a relative ratio, and determine a first abnormal state based on a first preset threshold;

[0127] a model parameter correction module, configured to apply a disturbance to the first thermal-electric coupling model to generate a second thermal-electric coupling model to correct parameter deviations;

[0128] The fault warning output module is used to generate a second abnormal state by combining the relative ratio and the second thermal-electric coupling model, and output graded warning information.

[0129] The present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program and is characterized in that the processor implements the steps of a cable terminal temperature monitoring method based on a capacitive coupling signal when executing the computer program.

[0130] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A cable terminal temperature monitoring method based on capacitive coupling signal, characterized by: include, collecting a voltage signal on the low-voltage side of a cable terminal to form first electrical data; constructing a first thermal-electric coupling model to convert the first electrical data into first temperature data; Comparing and analyzing the first temperature data of a plurality of cable terminals to obtain a relative ratio, and determining a first abnormal state based on a first preset threshold; applying a disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model; The relative ratio is combined with the second thermal-electric coupling model to generate a second abnormal state and output warning information.

2. A cable terminal temperature monitoring method based on capacitive coupling signal according to claim 1, characterized in that: Collecting the voltage signal on the low-voltage side of the cable terminal to form the first electrical data includes: Obtaining a voltage signal outputted from the low-voltage side of the cable terminal; First electrical data including timing characteristics is formed.

3. A cable terminal temperature monitoring method based on capacitive coupling signal according to claim 2, characterized in that: The constructing of the first thermal-electric coupling model and converting the first electrical data into first temperature data comprises: Establish the relationship between temperature change rate and current, thermal resistance and ambient temperature; The nonlinear relationship between the dielectric constant of the insulating medium and the material temperature is decomposed into a polynomial or exponential function form, namely the first thermal-electric coupling model.

4. A cable terminal temperature monitoring method based on capacitive coupling signal according to claim 3, characterized in that: Comparing and analyzing the first temperature data of the plurality of cable terminals to obtain a relative ratio, and determining a first abnormal state based on a first preset threshold comprises: Collect low-voltage side voltage signals of multiple cable terminals and calculate the relative ratio of the low-voltage side voltage signal of each cable terminal; Calculating the mean value of the voltage signal as a reference; The equivalent temperature difference is inferred through coupling calculation of the capacitance voltage division formula and the dielectric constant-temperature function, and the first abnormal state is determined in combination with the first preset threshold.

5. The cable terminal temperature monitoring method based on capacitive coupling signal according to claim 4, characterized in that: The coupling calculation of the capacitance voltage division formula and the dielectric constant-temperature function includes: Obtain voltage data at different temperatures through controlled variable experiments; The corresponding curves of voltage and temperature change are fitted to form a mapping relationship for inverse temperature difference.

6. A cable terminal temperature monitoring method based on capacitive coupling signal according to claim 5, characterized in that: Applying a disturbance to the first thermal-electric coupling model to form a second thermal-electric coupling model includes: Set tolerance ranges for copper conductor resistance, resin thermal resistance, and initial temperature parameters; The copper conductor resistance, resin thermal resistance and initial temperature parameters are randomly sampled and simulated multiple times, and the voltage-temperature curve is fitted and corrected by using the Monte Carlo simulation method.

7. A cable terminal temperature monitoring method based on capacitive coupling signal according to claim 6, characterized in that: The step of combining the relative ratio with the second thermal-electric coupling model to generate a second abnormal state and outputting warning information includes: Set up abnormality determination strategies for multiple consecutive cycles; If the second preset threshold value is exceeded for multiple consecutive periods, an early warning signal is output.

8. A system for improving short-term high-frequency energy storage efficiency, using a cable terminal temperature monitoring method based on capacitive coupling signals as described in any one of claims 1 to 7, characterized in that: include: An electrical data acquisition module, configured to acquire a voltage signal on the low-voltage side of the cable terminal and generate first electrical data; a thermoelectric coupling modeling module, configured to construct a first thermoelectric coupling model based on the first electrical data and convert a voltage signal into first temperature data; a multi-point comparison and analysis module, configured to compare and analyze first temperature data of a plurality of cable terminals, calculate a relative ratio, and determine a first abnormal state based on a first preset threshold; a model parameter correction module, configured to apply a disturbance to the first thermal-electric coupling model to generate a second thermal-electric coupling model to correct parameter deviations; The fault warning output module is used to generate a second abnormal state by combining the relative ratio with a second thermal-electric coupling model, and output graded warning information.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a cable terminal temperature monitoring method based on capacitive coupling signals according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a cable terminal temperature monitoring method based on capacitive coupling signals according to any one of claims 1 to 7 are implemented.

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