Core wire decoupling method and device for online monitoring of insulation damage of multi-core cable

Abstract

The invention provides a core wire decoupling method for online monitoring of insulation damage of a multi-core cable and a signal electromagnetic coupling injection device, and the method comprises the steps: modulating a cable insulation damage monitoring signal in a time-frequency domain; injecting the modulated monitoring signal into a multi-core cable through an electromagnetic coupling method; reflection signals generated by the core wires at the cable insulation impedance discontinuous points are received respectively; calculating a system propagation coefficient according to the received reflection signal, analyzing the discontinuity degree of the cable insulation impedance, and obtaining a cable insulation impedance parameter group; if the impedance discontinuity degree is not greater than the given threshold value, injecting the modulated monitoring signal again after a given time interval; and if the impedance discontinuity degree is greater than a given threshold value, decomposing the distribution parameters of the insulation impedance through a multi-core impedance decoupling method, identifying the core wire with insulation damage, and positioning the position of the core wire. According to the invention, positioning and mode identification can be realized for conventional cable insulation damage, and the problems of positioning and damage condition identification of cable insulation damage monitoring are solved.

Description

Technical Field

[0001] The present application relates to the technical field of cable insulation damage monitoring engineering, and in particular to a core wire decoupling method and a signal electromagnetic coupling injection device for online monitoring of multi-core cable insulation damage. Background Art

[0002] Multi-core cables have been widely used in power systems, rail transit and other fields due to their large transmission capacity and ability to achieve synchronous transmission of energy and signals. However, cables are subject to the combined effects of electrical and thermal aging over the years, and the operating environment is often dark and humid, making them susceptible to mechanical external forces, resulting in single-core failures that affect the stable transmission of energy or signals.

[0003] Existing cable damage detection methods, such as polarization-depolarization current method and superposition method, often detect the overall insulation status of the cable and cannot accurately distinguish the faulty core wire and the fault location. Existing traveling wave detection mainly relies on direct electrical connection for signal injection and reception. The equipment is difficult to install and it is difficult to achieve online monitoring of the operation process of multi-core cables. In addition, multi-core cables often have many core wires and small wire diameters. It is time-consuming and labor-intensive to sequentially detect the core wires, and online condition monitoring is difficult to achieve. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the first objective of the present application is to propose a core wire decoupling method for online monitoring of insulation damage in a multi-core cable.

[0006] The second objective of the present application is to provide a signal electromagnetic coupling injection device for online monitoring of insulation damage of multi-core cables.

[0007] The third objective of the present application is to provide an electronic device.

[0008] A fourth objective of the present application is to provide a computer-readable storage medium.

[0009] A fifth object of the present application is to provide a computer program product.

[0010] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a core wire decoupling method for online monitoring of insulation damage of a multi-core cable, comprising:

[0011] Modulate the cable insulation damage monitoring signal in the time-frequency domain;

[0012] The modulated monitoring signal is injected into the multi-core cable by electromagnetic coupling method;

[0013] Respectively receive the reflected signals generated by each core wire at the discontinuity point of the cable insulation impedance;

[0014] Calculate the system propagation coefficient based on the received reflected signal, analyze the discontinuity of the cable insulation impedance, and obtain the cable insulation impedance parameter group;

[0015] If the impedance discontinuity is not greater than a given threshold, the modulated monitoring signal is injected again after a given time interval; if the impedance discontinuity is greater than a given threshold, the distribution parameters of the insulation impedance are decomposed by the multi-core impedance decoupling method to identify the core wire with insulation damage and locate its position.

[0016] Optionally, the modulating the cable insulation damage monitoring signal in the time-frequency domain includes:

[0017] Through amplitude modulation, frequency modulation or pseudo-random number signal generation methods, a variety of complex signals or real signals modulated in the time and frequency domains are obtained.

[0018] Optionally, also include:

[0019] Use current transformers, voltage transformers or bridge cables to inject monitoring signals and receive reflected signals.

[0020] Optionally, the cable insulation impedance parameter group includes:

[0021] The apparent resistance R, inductance L, capacitance C and conductance G per unit length of the cable are obtained through the cable transfer function.

[0022] Optionally, decomposing the distribution parameters of the insulation impedance by a multi-core impedance decoupling method, identifying the core wire with insulation damage and locating its position, includes:

[0023] The voltage phasor matrix at the distance signal injection point x of the n-core cable is constructed by the cable insulation impedance parameter group. Current phasor matrix The propagation coefficient matrix Γ is expressed as:

[0024]

[0025] In the formula, The subscripts indicate the corresponding core wires. is the cable propagation coefficient;

[0026] Construct the decoupling matrix Q of the symmetric propagation coefficient matrix Γ, which satisfies:

[0027]

[0028] QQ T =I

[0029] Among them, Γ sis the decoupled cable propagation coefficient matrix;

[0030] Voltage phasor matrix With the current phasor matrix Perform decoupling transformation to obtain the decoupled voltage phasor matrix Current phasor matrix satisfy

[0031] Using the decoupled voltage phasor matrix and the current phasor matrix Calculate the cable propagation coefficient γ of each core 11s ,γ 22s ,…,γ kks ,…,γ nns ;

[0032] The difference between the propagation coefficient of each cable and the reference value is calculated. If the difference exceeds the set threshold, it is marked as abnormal, and the core wire with abnormal cable propagation coefficient is identified to locate its fault position.

[0033] To achieve the above-mentioned purpose, the second embodiment of the present application proposes a signal electromagnetic coupling injection device for online monitoring of insulation damage of a multi-core cable, comprising:

[0034] A signal modulation module, used to send out a cable insulation damage monitoring signal with time-frequency characteristics;

[0035] Signal injection module, used to improve the monitoring signal carrying capacity and inject the monitoring signal into the cable through electromagnetic relationship;

[0036] A filtering acquisition module, used to receive the complete echo signal, filter it and retain the time-frequency characteristics related to the injected signal;

[0037] The main control module is used to give the signal generation control signal to the signal modulation module, give the timing enable signal to the signal injection module, store the echo signal from the filtering and acquisition module, and pass it to the analysis and calculation module;

[0038] The analysis and positioning module is used to analyze the degree of impedance discontinuity, perform multi-core decoupling, and identify defective cable cores and defect locations.

[0039] Optionally, the signal injection module further includes a mutual inductor, a power amplifier, and a current limiter, wherein:

[0040] The power amplifier is connected in series with the transformer via the current limiter, and the transformer includes a variety of current transformers and voltage transformers;

[0041] The power amplifier is used to receive the cable insulation damage online monitoring signal from the signal modulation module and amplify it to improve the load capacity;

[0042] The current limiter is used to filter out the power frequency signal collected by the mutual inductor to prevent it from causing damage to the power amplifier;

[0043] The mutual inductor is used to inject the cable insulation damage online monitoring signal into the cable through an electromagnetic coupling relationship.

[0044] Optionally, the main control module is based on an embedded chip and is connected to other modules via a strong and weak current isolation device.

[0045] Optionally, the analysis and positioning module is used to:

[0046] Combining a digital signal processing method with a multi-core decoupled cable distributed parameter model, the filtered echo signal is analyzed to identify defective cores and determine the defect locations. The digital signal processing method includes time domain analysis, frequency domain analysis, and wavelet transform.

[0047] To achieve the above-mentioned purpose, the third aspect of the present application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0048] The memory stores computer-executable instructions;

[0049] The processor executes the computer-executable instructions stored in the memory to implement the method as described in any one of the first aspects.

[0050] To achieve the above-mentioned purpose, the fourth aspect embodiment of the present application proposes a computer-readable storage medium, in which computer-readable storage medium is stored computer execution instructions, and when the computer execution instructions are executed by a processor, they are used to implement the method as described in any one of the first aspects.

[0051] To achieve the above-mentioned purpose, the fifth aspect of the present application proposes a computer program product, which implements any method in the first aspect when executed by a processor.

[0052] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0053] This application uses electromagnetic coupling to synchronously inject detection signals into multi-core cables, obtains the core wire echo signal, and then uses a matrix method to decouple the propagation coefficient matrix to obtain the cable single core propagation coefficient. Compared with the non-decoupling method, this application can obtain more accurate positioning effects while obtaining single core defect information, can realize positioning and pattern recognition for conventional cable insulation damage, and can realize long-term monitoring of cable insulation damage and extraction of damaged core wire information, solving the positioning and damage identification problems of cable insulation damage monitoring.

[0054] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0056] Figure 1 A schematic flow chart of a core wire decoupling method for online monitoring of insulation damage of a multi-core cable provided in an embodiment of the present application;

[0057] Figure 2 This is a structural block diagram of a signal electromagnetic coupling injection device for online monitoring of multi-core cable insulation damage provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0059] In response to the problems existing in the prior art, an embodiment of the present application provides a core wire decoupling method for online monitoring of multi-core cable insulation damage, which can locate and recognize patterns of conventional cable insulation damage, and can also realize long-term monitoring of cable insulation damage and extraction of damaged core wire information, thereby solving the problems of positioning and damage identification in cable insulation damage monitoring.

[0060] Figure 1 A schematic flow chart of a core wire decoupling method for online monitoring of insulation damage of a multi-core cable provided in an embodiment of the present application. Figure 1 As shown, the method comprises the following steps:

[0061] Step 101: modulate the cable insulation damage monitoring signal in the time-frequency domain.

[0062] In the initial stage of cable insulation damage monitoring, in order to ensure that the monitoring signal has sufficient resolution and anti-interference ability, the signal needs to be modulated in the time and frequency domain. This process is the basis of the entire monitoring method. By giving the signal specific time and frequency characteristics, the subtle changes in the cable insulation impedance can be captured more accurately.

[0063] Common modulation methods include amplitude modulation, frequency modulation, and pseudo-random number signal generation. Amplitude modulation transmits information by adjusting the change of signal amplitude over time, making the signal easier to detect during reflection and reception. Frequency modulation adjusts the instantaneous frequency of the signal to make the propagation characteristics of the signal in different frequency bands more significant, thereby improving the ability to identify impedance discontinuities. In addition, pseudo-random number signal generation is a widely used modern modulation method. By constructing signals with high correlation and random characteristics, it can effectively distinguish monitoring signals from noise in complex environments. This application does not specifically limit the modulation method.

[0064] Through the above modulation method, the generated complex signal or real signal not only has strong time-frequency characteristics, but also can adapt to the complex transmission conditions inside the multi-core cable. When these modulated signals propagate in the cable, the transfer function of the cable can reflect its internal physical characteristics, especially when the insulation damage causes impedance discontinuity, the reflection characteristics of the modulated signal will become more significant. In this way, not only can the sensitivity of the monitoring signal be improved, but also a solid technical foundation is laid for subsequent signal injection, reflection signal reception and damage analysis.

[0065] Step 102: inject the modulated monitoring signal into the multi-core cable through an electromagnetic coupling method.

[0066] Injecting modulated monitoring signals into multi-core cables through electromagnetic coupling is an important step in achieving insulation damage monitoring. The technical solution proposed in this application efficiently transmits monitoring signals with time-frequency characteristics to the inside of the cable in a non-contact manner, thereby providing key data support for subsequent damage analysis. This method can avoid physical damage to the core wire while ensuring the normal operation of the cable, and has high practicality and reliability.

[0067] Specifically, this application uses a variety of electromagnetic coupling devices to achieve signal injection, such as current transformers, voltage transformers and bridge cables. The current transformer injects the modulated signal into the cable by inducing current. It is suitable for large current scenarios and has a high coupling efficiency. The voltage transformer completes signal coupling by inducing voltage, and performs well in scenarios where the cable voltage characteristics need to be detected. The bridge cable, as a flexible coupling device, can be directly connected to the target cable, realize signal injection through simple operation, and ensure the integrity and stability of signal transmission.

[0068] The electromagnetic coupling method of the present application has the following advantages: First, it can adapt to the complex electromagnetic environment inside the multi-core cable, and by adjusting the coupling parameters, it can achieve effective signal injection into different cores. Secondly, this method can significantly improve the carrying capacity of the injected signal, so that the monitoring signal remains stable during transmission and reduces losses. In addition, the present application also focuses on the safety of the signal injection process to avoid short circuits or damage problems that may be caused by direct contact with the cable core.

[0069] Through the technical solution of this application, the modulated monitoring signal can be accurately injected into the cable, and when propagating in the cable, it will produce corresponding reflections with the impedance changes caused by insulation damage, providing a solid foundation for subsequent signal reception, processing and insulation status analysis. This embodiment demonstrates the wide applicability and technological advancement of this application in complex cable monitoring scenarios.

[0070] Step 103: respectively receive the reflection signal generated by each core wire at the discontinuity point of the cable insulation impedance.

[0071] Receiving the reflected signals generated by each core at the discontinuity point of the cable insulation impedance is an important step in locating insulation damage. The technical solution proposed in this application uses electromagnetic coupling technology to efficiently receive reflected signals and retain their key features, providing a reliable basis for subsequent signal processing and analysis.

[0072] In the specific implementation process, this application uses devices such as current transformers, voltage transformers and bridge cables to receive the reflected signals of each core wire. The current transformer accurately captures the changes in the core wire state by sensing the reflected current signal, and is suitable for processing reflected signals in high current scenarios. The voltage transformer can better reflect the voltage characteristics at the impedance discontinuity point by sensing the reflected voltage signal, which is particularly suitable for scenarios where insulation faults have a greater impact on voltage distribution. As a flexible connection device, the bridge cable can directly receive the reflected signal in the multi-core cable and retain the integrity and continuity of the signal.

[0073] The signal receiving method of the present application has the following characteristics: First, through the non-contact electromagnetic coupling device, high-sensitivity detection of the reflected signal can be achieved without affecting the normal operation of the cable. Secondly, the receiving device of the present application can adapt to the complex transmission environment of multi-core cables, effectively distinguish the source of the reflected signal between different core wires, and ensure the independence of the signals of each core wire. In addition, the device of the present application can effectively filter out environmental noise and interference signals during the signal reception process, and only retain the part that is correlated with the injected signal, thereby improving the accuracy and efficiency of signal processing.

[0074] Through the technical solution of the present application, the received reflected signal can truly reflect the discontinuity and distribution characteristics of the cable insulation impedance. When the insulation damage of a core wire causes impedance changes, the reflected signal will produce obvious characteristic changes, providing the necessary data support for the precise positioning of the damage. This embodiment shows that the signal receiving method of the present application has strong applicability and technical advantages in complex cable environments, laying the foundation for efficient and accurate insulation damage monitoring.

[0075] Step 104: Calculate the system propagation coefficient according to the received reflected signal, analyze the discontinuity of the cable insulation impedance, and obtain a cable insulation impedance parameter group.

[0076] Calculating the system propagation coefficient based on the received reflected signal and analyzing the discontinuity of the cable insulation impedance are important steps to achieve insulation status assessment and damage location. This application can effectively extract the key parameters of the cable by accurately modeling and calculating the electromagnetic characteristics inside the cable, thereby reflecting the changes in the insulation status.

[0077] Specifically, the present application first uses the reflected signal to calculate the propagation coefficient γ of the cable, which is expressed as:

[0078]

[0079] Among them, R, L, C and G are the apparent resistance, inductance, capacitance and conductance per unit length respectively, and ω is the angular frequency of the signal. By calculating and analyzing these parameters, the discontinuity of the cable insulation impedance can be fully evaluated, thereby revealing potential insulation damage.

[0080] Specifically, this application extracts the above parameter group based on the transfer function of the cable:

[0081] (1) Apparent resistance R: reflects the loss characteristics of the cable conductor. When insulation damage causes leakage current to increase, the value of R will change significantly.

[0082] (2) Inductance L: describes the magnetic properties of the cable, and its variation is related to the physical integrity of the core wire;

[0083] (3) Capacitance C: It measures the energy storage capacity of the insulation layer. When the insulation layer is damaged or aged, the value of C usually decreases.

[0084] (4) Conductivity G: reflects the leakage characteristics of the insulation layer. Insulation damage will cause the value of G to increase.

[0085] By calculating the system propagation coefficient, the present application can further analyze the discontinuity of impedance. If the discontinuity of impedance is low, it indicates that the insulation state is relatively good; if the discontinuity is high, it indicates that there may be insulation damage points. The method of the present application can not only evaluate the overall insulation state, but also accurately identify abnormal points of insulation impedance through changes in distributed parameters.

[0086] In addition, the application uses the calculated cable parameter group to provide the necessary basic data for subsequent multi-core impedance decoupling. The accurate acquisition of these parameters is not only the core link of cable insulation status monitoring, but also an important basis for achieving accurate fault location and repair decision-making. This embodiment demonstrates the efficiency and practicality of the application technology in complex multi-core cable insulation status monitoring.

[0087] Step 105: If the impedance discontinuity is not greater than a given threshold, the modulated monitoring signal is injected again after a given time interval; if the impedance discontinuity is greater than a given threshold, the distribution parameters of the insulation impedance are decomposed by a multi-core impedance decoupling method to identify the core wire with insulation damage and locate its position.

[0088] Before executing this step, the cable monitoring process needs to be dynamically adjusted according to the magnitude of the impedance discontinuity to achieve efficient insulation status monitoring and fault location. When the impedance discontinuity is not greater than a given threshold, it indicates that the cable insulation is in good condition or has changed little. At this time, there is no need to perform further complex calculations and analysis immediately. Instead, the modulated monitoring signal is injected again after a predetermined interval and the aforementioned monitoring process is repeated. This design can continuously monitor the insulation status of the cable while saving system resources, ensuring that potential problems can be discovered in a timely manner.

[0089] If the impedance discontinuity is greater than a given threshold, it means that there may be obvious insulation damage in certain locations of the cable, and further measures need to be taken for precise analysis. The present application proposes a method based on multi-core impedance decoupling. By decomposing the distribution parameters of the insulation impedance, it can efficiently identify the core wires with insulation damage and accurately locate the damage location. The core of the multi-core impedance decoupling method is to use the cable propagation characteristic matrix and its diagonalization technology to extract the independent propagation coefficient of each core wire. By constructing a propagation coefficient matrix and a decoupling matrix, the coupled multi-core signal is decomposed into a single-core signal to obtain the propagation characteristic parameters of each core wire, such as the propagation coefficient. When the propagation coefficient of a core wire deviates significantly from the normal value, it can be determined that it has insulation damage. Specifically, the steps of the multi-core impedance decoupling method include:

[0090] First, the voltage phasor matrix at the distance signal injection point x of the n-core cable is constructed by the cable insulation impedance parameter group. Current phasor matrix The propagation coefficient matrix Γ is expressed as:

[0091]

[0092] In the formula, The subscripts indicate the corresponding core wires. is the cable propagation coefficient, and the components of the voltage phasor matrix and the current phasor matrix represent the voltage and current phasors of each core wire, respectively.

[0093] Next, the decoupling matrix Q of the symmetric propagation coefficient matrix Γ is constructed to satisfy the following conditions:

[0094]

[0095] QQ T =I

[0096] Among them, Γ s It is the propagation coefficient matrix of the decoupled cable, and its diagonal elements represent the independent propagation coefficients of each core.

[0097] Then, the voltage phasor matrix With the current phasor matrix Perform decoupling transformation to obtain the decoupled voltage phasor matrix Current phasor matrix satisfy Decoupled matrix and Provides independent propagation characteristics for each core.

[0098] Then, using the decoupled voltage phasor matrix and the current phasor matrix Calculate the cable propagation coefficient γ of each core 11s ,γ 22s ,…,γ kks ,…,γ nns These propagation coefficients are important indicators for analyzing the insulation condition.

[0099] Finally, the difference between the propagation coefficient of each cable and the reference value is calculated. If the difference exceeds the set threshold, the core wire is marked as abnormal, and the fault position is further located based on the distribution characteristics of the propagation coefficient.

[0100] It should be noted that the reference value needs to be set according to the actual scenario, and this application does not make any specific limitations on this.

[0101] This multi-core impedance decoupling method can accurately identify cores with abnormal propagation coefficients and provide accurate damage location information, providing a scientific basis for the diagnosis and repair of cable insulation damage. The technical solution of this application not only improves the efficiency of insulation status monitoring, but also enhances the adaptability and stability in complex multi-core cable environments.

[0102] In the embodiment of the present application, in order to verify the effectiveness of the multi-core impedance decoupling method, a test was conducted on a 50m long four-core unshielded cable. Two typical defect scenarios were set in the test: a circuit break defect (i.e., defect 1) of core 1 was set 20m away from the signal injection point; and a circuit break defect (i.e., defect 2) of core 2 and core 3 was set at 25m away from the signal injection point. The positioning results and their relative errors are shown in Table 1.

[0103] Table 1

[0104] Defect Number Actual location of defect Non-decoupled method positioning Decoupling method positioning 1 20m 21.54m±0.63m 19.95m±0.31m 2 25m 25.62m±0.52m 25.10m±0.21m

[0105] It can be seen from the table that the multi-core impedance decoupling method has significant advantages in defect location compared with the non-decoupling method. The specific analysis is as follows:

[0106] (1) Positioning of defect 1: The positioning result of the non-decoupling method is 21.54 m, with a large error range (±0.63 m) and deviating from the actual position; while the positioning result of the decoupling method is 19.95 m, with an error range of only ±0.31 m, which is closer to the actual position.

[0107] (2) Positioning of defect 2: The positioning result of the non-decoupling method is 25.62 m, and the error range is ±0.52 m. Although it is close to the actual position, the accuracy is still insufficient. The positioning result of the decoupling method is 25.10 m, and the error range is further reduced to ±0.21 m, which reflects a higher positioning accuracy.

[0108] The test results show that the multi-core impedance decoupling method not only performs well in distinguishing defective cores, but also is significantly better than the non-decoupling method in accurately locating the defect position. This is due to the fact that the decoupling method can effectively decompose the coupled signals in the multi-core cable, extract the propagation characteristics of the single core, eliminate the signal interference and error accumulation between the cores, and finally achieve higher positioning accuracy and reliability. This method provides strong technical support for the accurate diagnosis of complex cable insulation damage.

[0109] In order to implement the above-mentioned embodiment, the present application also proposes a signal electromagnetic coupling injection device for online monitoring of insulation damage of a multi-core cable. Figure 2 The schematic diagram of the structure of a signal electromagnetic coupling injection device for online monitoring of insulation damage of a multi-core cable provided in the embodiment of the present application clearly shows the functions of each module and their cooperative relationship from the overall structure. Figure 2 As shown, the device comprises:

[0110] The signal modulation module 1 is used to send out a cable insulation damage monitoring signal with time-frequency characteristics.

[0111] This module is responsible for generating cable insulation damage monitoring signals with specific time-frequency characteristics. These signals can be generated by amplitude modulation, frequency modulation or pseudo-random number generation to ensure high resolution and anti-interference ability of the signal during propagation. The signal modulation module is the signal source of the entire device and provides core data support for subsequent signal injection and processing.

[0112] The signal injection module 2 is used to improve the monitoring signal carrying capacity and inject the monitoring signal into the cable through electromagnetic relationship.

[0113] The main function of this module is to inject the monitoring signal into the target cable through electromagnetic coupling. In order to improve the stability and effectiveness of the signal propagation inside the cable, the module is equipped with a power amplifier to enhance the signal carrying capacity, and at the same time combines electromagnetic coupling devices such as current transformers, voltage transformers or bridge cables to achieve lossless and efficient signal injection.

[0114] The filtering and acquisition module 3 is used to receive the complete echo signal, filter it and retain the time-frequency characteristics related to the injected signal.

[0115] This module is used to receive the complete echo signal reflected from the cable and filter the signal to retain the time-frequency characteristics related to the injected signal. By eliminating external interference and noise signals, the module can ensure that the extracted reflection signal has higher accuracy and provide reliable data for subsequent analysis.

[0116] The main control module 4 is used to provide a signal generation control signal to the signal modulation module, provide a timing enable signal to the signal injection module, store the echo signal from the filtering and acquisition module, and transmit it to the analysis and calculation module.

[0117] The main control module 4 is the control core of the device, and its functions include: sending control signals to the signal modulation module to trigger signal generation, sending timing enable signals to the signal injection module to coordinate the timing of signal injection, and storing echo signals from the filtering acquisition module. In addition, the main control module is also responsible for passing the collected signals to the analysis and positioning module for further processing and analysis.

[0118] In addition, the main control module 4 is based on embedded chips such as single-chip microcomputers and FPGAs, and is responsible for coordinating and controlling the operation of the entire system. In order to ensure the safety and reliability of the system, the main control module 4 is connected to the remaining modules through a strong and weak current isolation device. The design of the strong and weak current isolation device can effectively avoid the adverse effects on the system operation caused by voltage and current differences or signal interference between different modules.

[0119] The analysis and positioning module 5 is used to analyze the impedance discontinuity degree, perform multi-core decoupling, and identify the defective cable core wires and defect locations.

[0120] This module is responsible for in-depth analysis of the echo signal and evaluating the discontinuity of the cable insulation impedance. By implementing the multi-core decoupling method, the analysis and positioning module can effectively identify defective cable cores and accurately locate the defect. The module combines multiple digital signal processing technologies such as time domain analysis, frequency domain analysis, and wavelet transform to further improve the accuracy and reliability of positioning.

[0121] Further, such as Figure 2 As shown, in the embodiment of the present application, the signal injection module 2 further includes a power amplifier 21 , a current limiter 23 and a mutual inductor 23 .

[0122] Specifically, the power amplifier 21 is used to receive the monitoring signal from the signal modulation module and amplify its power to improve the signal carrying capacity. In a multi-core cable environment, the role of the power amplifier is particularly important because the signal may be affected by the coupling effect and attenuation inside the cable. By amplifying the signal power, it is ensured that it can propagate to a sufficient distance in the cable and maintain a high signal-to-noise ratio.

[0123] The current limiter 22 is connected in series between the power amplifier and the transformer to filter out irrelevant interference signals such as power frequency signals that may be collected by the transformer. The power frequency signal may cause unnecessary damage to the power amplifier, so the design of the current limiter can not only protect the power amplifier, but also optimize the stability and safety of signal injection.

[0124] The transformer 23 is a key device for realizing electromagnetic coupling in the signal injection module, including a variety of current transformers and voltage transformers. Its function is to efficiently couple the modulated cable insulation damage online monitoring signal to the target cable by electromagnetic induction. The diverse design of the transformer enables it to adapt to different application scenarios, such as adapting to different cable types and working environments, to ensure the flexibility and reliability of signal injection.

[0125] Through the collaboration of the above components, the signal injection module can effectively realize the non-contact injection of monitoring signals. First, the monitoring signal generated by the signal modulation module is amplified by the power amplifier and then preliminarily cleaned by the current limiter to avoid the influence of power frequency interference. Subsequently, the high-quality monitoring signal is injected into the target cable through the electromagnetic coupling of the mutual inductor. The whole process is efficient and stable, and will not interfere with the normal operation of the cable.

[0126] Further, such as Figure 2 As shown, the filter acquisition module 3 in the embodiment of the present application is further optimized and designed, and also includes an amplifier 31, a current limiter 32 and a sensor 33.

[0127] Specifically, the amplifier 31 is used to preliminarily amplify the received echo signal. Since the echo signal may be attenuated during the propagation process, the amplifier can effectively enhance the signal strength and improve the signal-to-noise ratio of the signal, thereby providing high-quality signal input for subsequent filtering and processing links.

[0128] The current limiter 32 is connected in series between the amplifier 31 and the sensor 33 to protect the safe operation of the entire filtering and acquisition module. The main function of the current limiter 32 is to filter out unnecessary current fluctuations and power frequency interference signals, ensure that the signal received by the sensor is purer, and prevent equipment damage due to excessive current.

[0129] The sensor 33 is the core component of the filter acquisition module, responsible for sensing the slight changes in the echo signal and converting it into an electrical signal that can be processed by the system. The high sensitivity design of the sensor can capture key characteristic signals that have time-frequency correlation with the injected signal, laying the foundation for further analysis of the signal.

[0130] Through the above design, the amplifier and the sensor are connected in series through the current limiter to form an efficient and safe signal processing link. After the echo signal is enhanced by the amplifier, the current limiter performs preliminary interference filtering on the signal, and finally the sensor accurately collects and converts it into a high-quality electrical signal. This modular design fully considers multiple factors such as signal attenuation, interference and equipment protection, ensuring the efficiency and stability of echo signal acquisition.

[0131] In order to implement the above embodiments, the present application also proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided by the above embodiments.

[0132] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0133] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0134] The collection, storage, use, processing, transmission, provision and disclosure of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0135] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0136] The present application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by limiting data collection and deleting the data. In addition, when applicable, such personal information is de-identified to protect the privacy of the user.

[0137] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0138] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0139] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0140] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), 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 disk 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 and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0141] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0142] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0143] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0144] The storage medium mentioned above may be a read-only memory, a disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

[0145] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0146] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A core wire decoupling method for online monitoring of insulation damage of a multi-core cable, characterized in that: The following steps are involved: Modulate the cable insulation damage monitoring signal in the time-frequency domain; The modulated monitoring signal is injected into the multi-core cable by electromagnetic coupling method; Respectively receive the reflected signals generated by each core wire at the discontinuity point of the cable insulation impedance; Calculate the system propagation coefficient based on the received reflected signal, analyze the discontinuity of the cable insulation impedance, and obtain the cable insulation impedance parameter group; If the impedance discontinuity is not greater than a given threshold, the modulated monitoring signal is injected again after a given time interval; if the impedance discontinuity is greater than a given threshold, the distribution parameters of the insulation impedance are decomposed by the multi-core impedance decoupling method to identify the core wire with insulation damage and locate its position.

2. The method according to claim 1, characterized in that The step of modulating the cable insulation damage monitoring signal in the time-frequency domain includes: Through amplitude modulation, frequency modulation or pseudo-random number signal generation methods, a variety of complex signals or real signals modulated in the time and frequency domains are obtained.

3. The method according to claim 2, characterized in that Also includes: Use current transformers, voltage transformers or bridge cables to inject monitoring signals and receive reflected signals.

4. The method according to claim 3, characterized in that The cable insulation impedance parameter group includes: The apparent resistance R, inductance L, capacitance C and conductance G per unit length of the cable are obtained through the cable transfer function.

5. The method according to claim 4, characterized in that The method of decomposing the distribution parameters of the insulation impedance by the multi-core impedance decoupling method, identifying the core wire with insulation damage and locating the position thereof, includes: The voltage phasor matrix at the distance signal injection point x of the n-core cable is constructed by the cable insulation impedance parameter group. Current phasor matrix The propagation coefficient matrix Γ is expressed as: In the formula, The subscripts indicate the corresponding core wires. is the cable propagation coefficient; Construct the decoupling matrix Q of the symmetric propagation coefficient matrix Γ, which satisfies: QQ T =I Among them, Γ s is the decoupled cable propagation coefficient matrix; Voltage phasor matrix With the current phasor matrix Perform decoupling transformation to obtain the decoupled voltage phasor matrix Current phasor matrix satisfy Using the decoupled voltage phasor matrix and the current phasor matrix Calculate the cable propagation coefficient γ of each core 11s ,γ 22s ,…,γ kks ,…,γ nns ; The difference between the propagation coefficient of each cable and the reference value is calculated. If the difference exceeds the set threshold, it is marked as abnormal, and the core wire with abnormal cable propagation coefficient is identified to locate its fault position.

6. A signal electromagnetic coupling injection device for online monitoring of insulation damage of a multi-core cable, used to execute the method according to any one of claims 1 to 5, characterized in that: include: A signal modulation module, used to send out a cable insulation damage monitoring signal with time-frequency characteristics; Signal injection module, used to improve the monitoring signal carrying capacity and inject the monitoring signal into the cable through electromagnetic relationship; A filtering acquisition module, used to receive the complete echo signal, filter it and retain the time-frequency characteristics related to the injected signal; The main control module is used to give the signal generation control signal to the signal modulation module, give the timing enable signal to the signal injection module, store the echo signal from the filtering and acquisition module, and pass it to the analysis and calculation module; The analysis and positioning module is used to analyze the degree of impedance discontinuity, perform multi-core decoupling, and identify defective cable cores and defect locations.

7. The device according to claim 6, characterized in that The signal injection module further includes a mutual inductor, a power amplifier, and a current limiter, wherein: The power amplifier is connected in series with the transformer via the current limiter, and the transformer includes a variety of current transformers and voltage transformers; The power amplifier is used to receive the cable insulation damage online monitoring signal from the signal modulation module and amplify it to improve the load capacity; The current limiter is used to filter out the power frequency signal collected by the mutual inductor to prevent it from causing damage to the power amplifier; The mutual inductor is used to inject the cable insulation damage online monitoring signal into the cable through an electromagnetic coupling relationship.

8. The device according to claim 7, characterized in that The main control module takes the embedded chip as the core and is connected with other modules through strong and weak current isolation devices.

9. The device according to claim 8, characterized in that The analysis and positioning module is used to: Combining a digital signal processing method with a multi-core decoupled cable distributed parameter model, the filtered echo signal is analyzed to identify defective cores and determine the defect locations. The digital signal processing method includes time domain analysis, frequency domain analysis, and wavelet transform.

10. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 5.

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