Cable partial discharge detection system

Abstract

The invention relates to a cable partial discharge detection system. The system comprises a signal processing device, a signal analysis device and at least two types of sensing devices, each sensing device is used for carrying out discharge detection on the cable under the condition of partial discharge of the cable to obtain at least two types of discharge sensing signals; the signal processing device is used for acquiring each discharge sensing signal and processing each discharge sensing signal to obtain a respective discharge processing signal of each discharge sensing signal; and the signal analysis device is used for carrying out signal analysis on each discharge processing signal based on the respective signal category of each discharge sensing signal, and determining the discharge result of the partial discharge of the cable. By adopting the system, the accuracy of cable partial discharge detection can be improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a cable partial discharge detection system. Background Art

[0002] With the increasing progress of power systems, cables have been widely used in various power transmission and distribution scenarios due to their excellent electrical and mechanical properties. However, in the operation of cables, partial discharge is a key issue that must be taken seriously. Although partial discharge may be relatively weak in the early stage, if it is not detected and handled in time, it will gradually develop and cause serious damage to the insulation of the cable.

[0003] In conventional technology, partial discharge conditions are generally determined by detecting the current signal of partial discharge. However, since the partial discharge phenomenon involves many complex discharge scenarios, determining the partial discharge condition only by detecting the current signal may result in inaccurate detection. Summary of the invention

[0004] Based on this, it is necessary to provide a cable partial discharge detection system that can improve detection accuracy in response to the above technical problems.

[0005] In a first aspect, the present application provides a cable partial discharge detection system, the system comprising a signal processing device, a signal analysis device, and at least two types of sensing devices;

[0006] Each of the sensing devices is used to perform discharge detection on the cable in the case of partial discharge of the cable, and obtain at least two types of discharge sensing signals;

[0007] The signal processing device is used to obtain each of the discharge sensor signals, and perform signal processing on each of the discharge sensor signals to obtain a discharge processing signal of each of the discharge sensor signals;

[0008] The signal analysis device is used to perform signal analysis on each of the discharge processing signals based on the signal category of each of the discharge sensing signals, so as to determine the discharge result of the partial discharge of the cable.

[0009] In one embodiment, the discharge sensing signal includes a fiber optic current signal, an electromagnetic signal, an ultrasonic signal, and an infrared signal; and the sensing device includes a fiber optic current sensing module, an electromagnetic sensing module, an ultrasonic sensing module, and an infrared sensing module.

[0010] In one embodiment, the signal processing device includes a signal enhancement module, a filtering module, and a denoising module.

[0011] In one embodiment, the signal analysis device is specifically used for:

[0012] determining a respective weight for each of the signal categories;

[0013] Based on a data weighted fusion algorithm, signal integration is performed on each of the discharge processing signals according to each of the weights to determine a discharge comprehensive signal of the cable partial discharge;

[0014] A discharge result of the partial discharge of the cable is determined based on the discharge comprehensive signal.

[0015] In one embodiment, the system further comprises a signal acquisition device; the signal acquisition device is connected to the sensor device and the signal processing device;

[0016] The signal acquisition device is used to acquire the discharge sensor signal detected by the sensor device and transmit the discharge sensor signal to the signal processing device.

[0017] In one of the embodiments, the system further comprises an alarm device;

[0018] The alarm device is used to detect the discharge intensity of the partial discharge of the cable, and feed back an alarm signal when the discharge intensity reaches a discharge threshold.

[0019] In one embodiment, the system further comprises a power supply device; the power supply device is connected to the sensing device, the signal processing device, and the signal analyzing device;

[0020] The power supply device is used to supply power to the sensing device, the signal processing device, and the signal analyzing device.

[0021] In one embodiment, the system further comprises a display device; the display device is connected to the sensor device;

[0022] The display device is used to obtain and display the discharge sensing signal from the sensing device.

[0023] In one of the embodiments, the system further comprises a report generating device;

[0024] The report generating device is used for generating a discharge monitoring report of the cable partial discharge based on the discharge result.

[0025] In one embodiment, the system further comprises a discharge evaluation device; the discharge evaluation device is connected to the signal processing device;

[0026] The discharge evaluation device is used to extract signal characteristics of the discharge processing signal to obtain signal characteristic parameters;

[0027] Based on the signal characteristic parameters, the discharge position and discharge intensity of the partial discharge are evaluated.

[0028] The above-mentioned cable partial discharge detection system includes a signal processing device, a signal analysis device, and at least two types of sensor devices. The sensor devices are configured to perform discharge detection on the cable in the case of partial discharge of the cable. Each of the sensor devices obtains at least two types of discharge sensor signals. In the case of partial discharge of the cable, the discharge sensor signal of the partial discharge of the cable can be determined to determine the partial discharge situation of the cable; the signal processing device is configured to obtain each discharge sensor signal and perform signal processing on each discharge sensor signal respectively to obtain a discharge processing signal of each discharge sensor signal, which can improve the clarity and accuracy of the discharge sensor signal; the signal analysis device is configured to perform signal analysis on each discharge processing signal based on the signal category of each discharge sensor signal to determine the discharge result of the cable partial discharge, which can perform comprehensive analysis on each discharge processing signal to improve the accuracy of determining the discharge result of the cable partial discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a structural block diagram of a cable partial discharge detection system in one embodiment;

[0031] Figure 2 is a structural block diagram of a sensing device in one embodiment;

[0032] Figure 3 is a structural block diagram of a signal processing device in one embodiment;

[0033] Figure 4 is a structural block diagram of a cable partial discharge detection system in another embodiment;

[0034] Figure 5 A structural block diagram of a cable partial discharge detection system in yet another embodiment;

[0035] Figure 6 A structural block diagram of a cable partial discharge detection system in yet another embodiment;

[0036] Figure 7 A structural block diagram of a cable partial discharge detection system in another embodiment;

[0037] Figure 8 A schematic diagram of the structure of a cable partial discharge detection system in one embodiment;

[0038] Fig. 9 A schematic diagram of the structure of a cable partial discharge detection system in yet another embodiment;

[0039] Fig.10 FIG. 4 is a schematic diagram of the structure of a cable partial discharge detection system in another embodiment. DETAILED DESCRIPTION

[0040] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0043] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0044] As described in the background technology, with the increasing advancement of power systems, cables have been widely used in various power transmission and distribution scenarios due to their excellent electrical and mechanical properties. However, in the operation of cables, partial discharge is a key issue that must be taken seriously. Although partial discharge may be relatively weak in the early stages, if it is not detected and treated in time, it will gradually develop and cause serious damage to the insulation of the cable. In traditional technology, partial discharge conditions are generally determined by detecting the current signal of partial discharge. However, since the partial discharge phenomenon involves many complex discharge scenarios, the partial discharge condition is determined only by detecting the current signal, which may result in inaccurate detection.

[0045] Based on the above reasons, the present invention provides a cable partial discharge detection system capable of improving detection accuracy.

[0046] In one embodiment, Figure 1 As shown, a cable partial discharge detection system is provided, which includes a signal processing device 10, a signal analysis device 20, and at least two types of sensor devices 30; each sensor device 30 is used to perform discharge detection on the cable in the case of partial discharge of the cable to obtain at least two types of discharge sensor signals; the signal processing device 10 is used to obtain each discharge sensor signal, and perform signal processing on each discharge sensor signal respectively to obtain a discharge processing signal of each discharge sensor signal; the signal analysis device 20 is used to perform signal analysis on each discharge processing signal based on the signal category of each discharge sensor signal to determine the discharge result of the cable partial discharge.

[0047] Among them, under the background of continuous development and improvement of the power system, cross-linked polyethylene cables have shown extremely broad application prospects and important positions in the field of global power transmission due to their excellent electrical properties, mechanical strength and heat resistance. Cables ensure the safety and stability of power transmission due to their excellent insulation properties. At the same time, their high current carrying capacity and small transmission loss also make them play an important role in long-distance power transmission and urban power grid construction. However, in the operation of cables, partial discharge is a key issue that must be paid attention to. Partial discharge, also known as micro-discharge phenomenon in insulation, is a short-term, pulsed discharge behavior that occurs inside the non-uniform dielectric in the cable insulation material under the action of a specific electric field strength.

[0048] Although this discharge may be relatively weak in the early stage, if it is not detected and treated in time, it will gradually develop and cause serious damage to the insulation of the cable. The partial discharge phenomenon will continuously erode the insulation performance of the cable, thereby accelerating the aging process of the cable and significantly reducing its expected service life.

[0049] Long-term partial discharge may also cause cable insulation breakdown, resulting in power outages, posing a great threat to the safe and stable operation of the power system. In addition, the heat energy and chemically active molecules caused by partial discharge will accelerate the aging process of the cable insulation layer.

[0050] The signal processing device 10 involves the analysis, operation and transformation of various types of signals (such as audio signals, image signals, biological signals, communication signals, etc.). Specifically for the present application, the signal processing device 10 includes a signal enhancement module 11, a filtering module 12, and a denoising module 13. The signal analysis device 20 is a device specifically used to measure, analyze and process signals. The sensing device 30 is an instrument that receives electromagnetic wave information of an object and converts this information into an electrical signal that is easy to amplify, transmit and calculate. Specifically for the present application, the sensing device 30 includes an optical fiber current sensing module 31, an electromagnetic sensing module 32, an ultrasonic sensing module 33, and an infrared sensing module 34. The discharge sensing signal is the sensing signal collected by the sensing device 30. The discharge processing signal is the signal processed by the signal processing device 10. The signal category refers to the signal category corresponding to the discharge sensing signal. For example, the signal category may include an optical fiber current signal, an electromagnetic signal, an ultrasonic signal, and an infrared signal. The discharge result can be used to characterize the discharge condition of the partial discharge of the cable.

[0051] Specifically, in order to accurately detect the partial discharge of the cable, at least two types of sensor devices 30 can be configured. When the cable has partial discharge, the cable is subjected to discharge detection to obtain at least two types of discharge sensor signals. After that, the signal processing device 10 obtains the above discharge sensor signals, and then performs signal processing on the above discharge sensor signals to obtain respective discharge processing signals of each discharge sensor signal. Finally, the signal analysis device 20 performs signal analysis on each discharge processing signal based on the signal category of each discharge sensor signal to determine the discharge result of the partial discharge of the cable. Exemplarily, the discharge sensor signal may include an optical fiber current signal, an electromagnetic signal, an ultrasonic signal, and an infrared signal. The sensor device 30 may include an optical fiber current sensor module 31, an electromagnetic sensor module 32, an ultrasonic sensor module 33, and an infrared sensor module 34. The signal analysis device 20 may perform a comprehensive analysis on the above signals based on the signal categories of the above optical fiber current signal, the electromagnetic signal, the ultrasonic signal, and the infrared signal to determine the discharge result of the partial discharge of the cable. It can be understood that the comprehensive analysis may be combined with weight analysis or directly analyze the above signals.

[0052] The above-mentioned cable partial discharge detection system includes a signal processing device 10, a signal analysis device 20, and at least two types of sensor devices 30. The sensor devices 30 are configured to perform discharge detection on the cable in the case of partial discharge of the cable. Each of the sensor devices 30 that obtains at least two types of discharge sensor signals can determine the discharge sensor signal of the cable partial discharge in the case of partial discharge of the cable to determine the partial discharge situation of the cable; the signal processing device 10 is configured to obtain each discharge sensor signal and perform signal processing on each discharge sensor signal respectively to obtain a discharge processing signal of each discharge sensor signal, which can improve the clarity and accuracy of the discharge sensor signal; the signal analysis device 20 is configured to perform signal analysis on each discharge processing signal based on the signal category of each discharge sensor signal to determine the discharge result of the cable partial discharge, which can perform comprehensive analysis on each discharge processing signal to improve the accuracy of determining the discharge result of the cable partial discharge.

[0053] In an exemplary embodiment, Figure 2 As shown, the discharge sensing signal includes a fiber optic current signal, an electromagnetic signal, an ultrasonic signal, and an infrared signal; the sensing device 30 includes a fiber optic current sensing module 31 , an electromagnetic sensing module 32 , an ultrasonic sensing module 33 , and an infrared sensing module 34 .

[0054] Among them, the fiber optic current signal does not directly transmit current, but uses optical fiber to transmit optical signals, and then converts the optical signals into electrical signals through a photoelectric converter. Electromagnetic signals refer to the joint propagation of electric and magnetic fields in space, which is manifested as changes in the intensity of the electric and magnetic fields. Ultrasonic waves can propagate in materials at a certain speed and direction, and will be reflected when encountering heterogeneous interfaces with different acoustic impedances (such as defects or the bottom surface of the object being tested). This reflection phenomenon can be used for ultrasonic flaw detection. Infrared signals are infrared radiation or infrared electromagnetic waves. All objects in nature that are higher than 0K (i.e., minus 273°C) radiate electromagnetic waves outward, and the infrared part of these electromagnetic waves is infrared signals.

[0055] The optical fiber current sensing module 31, in this embodiment, is an optical fiber current transformer (FOCT), which is a device that uses optical fiber technology to measure current and is widely used in cable partial discharge (PD) detection. Its core mechanism and detailed introduction are as follows: Core mechanism measurement principle: The optical fiber current transformer is mainly based on the Faraday effect, which means that the polarization state of light in the optical fiber will change under the action of an external magnetic field.

[0056] When current passes through a conductor, a magnetic field is generated around it. Fiber-optic current transformers use this principle to detect changes in the magnetic field generated by current through light propagation inside the optical fiber. Signal conversion: When the light beam in the fiber-optic sensor passes through a magnetic field, its polarization state changes due to the Faraday effect. By measuring the change in the polarization state of light, a signal proportional to the current can be obtained.

[0057] After conditioning, this signal can be used to analyze partial discharge conditions inside the cable.

[0058] Optical fiber: Usually specially designed optical fiber is used, which has good anti-interference and high sensitivity. Polarization controller: It is used to adjust the polarization state of the light beam in the optical fiber to improve the measurement accuracy.

[0059] Optical sensor: A device that converts optical signals into electrical signals, usually composed of photodetectors. Signal processing module: Responsible for filtering, amplifying, sampling and converting the detected signals for subsequent data analysis. High precision: Fiber optic current transformers have superior measurement accuracy and can accurately measure weak current changes in high voltage environments. Strong anti-interference ability: Because it is based on fiber optic technology, fiber optic current transformers are not subject to electromagnetic interference and are suitable for use in complex electromagnetic environments. High safety: The optical fiber itself is non-conductive, has high safety, and can operate in high voltage and high current environments. Fast response speed: It can respond to current changes in real time and is suitable for rapid detection of partial discharge signals. In cable partial discharge detection, fiber optic current transformers can effectively capture weak current changes caused by partial discharge, and provide comprehensive cable health status monitoring by combining with other sensors (such as electromagnetic coupling sensors, ultrasonic sensors, etc.). Therefore, for fiber optic sensors, the key is to have effective interference suppression capabilities and accurate partial discharge signal extraction technology to ensure the accuracy and reliability of the test results. During the field test, the high-frequency through-type current transformer was accurately placed on the grounding down conductor of the metal shielding layer at the end of the cable. When partial discharge occurs inside the cable, the generated pulse current will act on the metal shielding layer due to electromagnetic induction. Subsequently, the current is conducted to the ground through the grounding wire, and the current changes in this process can be captured and monitored by the optical fiber sensor.

[0060] The electromagnetic sensing module 32 is an electromagnetic coupling sensor in this embodiment, which is specially designed to detect ultra-high frequency electromagnetic wave signals generated by partial discharge. The electromagnetic coupling sensor plays a vital role in the detection of partial discharge (PD) in cables. It uses the changes in the electromagnetic field around the cable to monitor the partial discharge phenomenon. Partial discharge generates high-frequency pulse currents in the power cable, which will generate instantaneous electromagnetic radiation in the surrounding area. The electromagnetic coupling sensor can capture these signals, thereby realizing the monitoring of partial discharge.

[0061] Core Mechanism Principle of electromagnetic induction: Partial discharge generates high-frequency current pulses in the cable, which form an electromagnetic field around the cable.

[0062] Electromagnetic coupling sensors capture the high-frequency signals generated by partial discharge by sensing these electromagnetic waves. The sensors are usually placed on the surface of the cable or close to the cable to sense the partial discharge pulse current flowing through the cable and the electromagnetic radiation generated.

[0063] High-frequency response capability: Electromagnetic coupling sensors are particularly sensitive to high-frequency signals generated by partial discharge, because partial discharge often produces transient, high-frequency pulse signals.

[0064] The frequency range of these signals is usually from tens of megahertz (MHz) to hundreds of megahertz (MHz), and electromagnetic coupling sensors separate useful discharge signals from background noise through selective filtering.

[0065] Coupling mechanism: The sensor is usually non-contact coupled to the cable through capacitance or inductance, that is, the sensor does not need to be directly connected to the cable conductor, but obtains the electromagnetic radiation signal through induction.

[0066] Capacitive coupling is suitable for detecting electric field changes caused by partial discharge, while inductive coupling is mainly used to sense magnetic field changes caused by partial discharge.

[0067] Structural composition: Coupling device: The electromagnetic coupling sensor can be designed as a ring or clip structure, which is put on the surface of the cable to capture electromagnetic signals in a non-contact manner. Common structures include loop antennas, inductor coils, etc. Amplifier circuit: Since the amplitude of the partial discharge signal is small, the electromagnetic coupling sensor integrates an amplifier circuit to amplify the captured weak signal for subsequent processing. Filter: In order to remove low-frequency noise or interference in the environment, the sensor usually has a built-in bandpass filter to selectively amplify and extract the high-frequency signal of partial discharge.

[0068] Signal conditioning unit: further processes the signal, including denoising and smoothing, to improve the signal-to-noise ratio and ensure that the system can accurately determine the partial discharge situation.

[0069] Working principle: When local discharge occurs, high-frequency pulse current flows in the cable, generating short-term electromagnetic field fluctuations. The electromagnetic coupling sensor converts the high-frequency pulse signal into a voltage signal by sensing these electromagnetic waves. After amplification and filtering, these signals are transmitted to the data acquisition module for analysis.

[0070] Non-contact monitoring: The electromagnetic coupling sensor does not need to directly contact the cable conductor, is easy to install, and is suitable for cable systems of various types and voltage levels.

[0071] Wide-band response: The sensor has good sensitivity to high-frequency signals of partial discharge, can capture transient discharge events, and has a wide frequency range to adapt to different types of partial discharge.

[0072] Anti-electromagnetic interference: Since the frequency of the partial discharge signal is significantly different from the background power frequency power signal, the electromagnetic coupling sensor can effectively suppress the power frequency interference through filtering and obtain a clear discharge signal.

[0073] Partial discharge signals are usually sudden and random. Electromagnetic coupling sensors can capture these short-term discharge events through their high-frequency response characteristics. The sensor can continuously monitor the working status of the cable and detect the frequency and intensity changes of partial discharge in real time, thereby helping to predict and prevent cable failures. It is suitable for on-site monitoring and online monitoring, especially during the operation of the cable system, and can monitor the health status of the cable in real time without power outages.

[0074] When partial discharge occurs in a cable, ultra-high frequency electromagnetic waves with a frequency of hundreds of megahertz are generated. Ultra-high frequency sensors receive these electromagnetic wave signals and convert them into electrical signal outputs for subsequent signal processing and analysis. Ultra-high frequency sensors usually use antenna structures, such as microstrip antennas and helical antennas, to improve the receiving sensitivity and directionality of ultra-high frequency electromagnetic waves. After amplification, filtering and other processing, the output signal of the sensor can be used for the detection, location and analysis of partial discharge.

[0075] The ultrasonic sensor module 33 is an ultrasonic sensor in this embodiment. Based on the characteristics of ultrasonic waves, it is used to perform various functions such as distance measurement, object detection and other measurement tasks. The ultrasonic sensor is an acoustic emission device based on the piezoelectric effect. Its working principle involves emitting ultrasonic pulses to the target object and then receiving the echo signal reflected by the object. The piezoelectric crystal inside its sensor generates ultrasonic waves under the excitation of electrical signals. These ultrasonic waves propagate in the air or other media and are reflected back after encountering the target object. After receiving the reflected echo, the sensor converts it into an electrical signal and calculates the distance to the target object by measuring the time difference between emission and reception. The working bandwidth of the sensor covers the frequency band of 20 to 180 kHz. The sensitivity parameter is set to 85 decibels (-75 decibels). The output result is presented as a differential signal. This amplifier is a voltage type, and its structure includes an integrated design of a two-stage amplifier and a fourth-order high-pass filter. The main reason is that the detected signal is often extremely weak, and the intensity may be as low as microvolts or even lower. Only after multi-stage amplification can the signal meet the standard requirements of data acquisition and processing.

[0076] The infrared sensor module 34, which is an infrared sensor in this embodiment, can monitor the temperature fluctuation of the cable in real time, has a fast response characteristic, and can feedback the temperature change within 0.1 seconds; it adopts non-contact temperature measurement technology, which is suitable for high voltage and high temperature environments to reduce measurement errors; it has an automatic calibration function to ensure measurement accuracy in long-term use; multiple thresholds can be set to adapt to different monitoring needs and improve safety.

[0077] Specifically, the discharge sensing signal refers to all types of signals that can be monitored during the discharge process, including optical fiber current signals, electromagnetic signals, ultrasonic signals, and infrared signals. The sensing device 30 includes an optical fiber current sensing module 31, an electromagnetic sensing module 32, an ultrasonic sensing module 33, and an infrared sensing module 34. Therefore, configuring the above sensing modules can perform discharge detection in multiple aspects during the cable partial discharge detection process, thereby improving the accuracy of partial discharge detection.

[0078] In an exemplary embodiment, Figure 3 As shown, the signal processing device 10 includes a signal enhancement module 11 , a filtering module 12 , and a denoising module 13 .

[0079] The signal enhancement module 11 can be used to enhance the signal strength. The filtering module 12 can filter the signal. The denoising module 13 can be used to reduce or eliminate the noise in the signal.

[0080] Specifically, for the collected partial discharge sensing signals, corresponding processing procedures can be implemented to extract key information. Common signal processing technologies cover multiple key links such as filtering, amplification, denoising and feature extraction. Taking the filter module 12 as an example, its application is to filter the signal and effectively eliminate high-frequency noise and low-frequency interference. At the same time, the amplitude of the signal is increased with the help of signal amplification technology, laying the foundation for subsequent analysis and processing. The signal is feature extracted using methods such as wavelet transform and Fourier transform to obtain characteristic parameters such as amplitude, frequency, and phase of partial discharge.

[0081] In this embodiment, by configuring the signal enhancement module 11, the filtering module 12, and the denoising module 13, the discharge sensing signal can be subjected to signal enhancement processing, filtering processing, and denoising processing, thereby improving the accuracy of cable partial discharge detection.

[0082] In an exemplary embodiment, the signal analysis device 20 is specifically used to: determine the weight of each signal category; based on a data weighted fusion algorithm, perform signal integration on each discharge processing signal according to each weight to determine a discharge comprehensive signal of cable partial discharge; and determine a discharge result of cable partial discharge based on the discharge comprehensive signal.

[0083] Among them, the data weighted fusion algorithm refers to the statistical analysis of multi-sensor data at different times and spaces, and then uses mathematical methods or practical experience to assign different weights to different sensor data, and finally obtains the data fusion value.

[0084] Specifically, after processing each discharge sensing signal to obtain a discharge processing signal, the signal analysis device 20 can determine the weight of each signal category, and perform signal integration on each discharge processing signal according to each weight to determine a discharge comprehensive signal of cable partial discharge; and determine the discharge result of cable partial discharge based on the discharge comprehensive signal. It can be understood that the process of determining the discharge result of cable partial discharge based on the discharge comprehensive signal can be to compare the discharge comprehensive signal with a preset standard comprehensive signal. If the discharge comprehensive signal is greater than or equal to the standard comprehensive signal, it can be considered that the discharge result is severe partial discharge.

[0085] In this embodiment, the discharge analysis device integrates the discharge processing signals according to the weights based on the data weighted fusion algorithm to determine the discharge comprehensive signal of the cable partial discharge, which can improve the accuracy of the partial discharge detection result.

[0086] In an exemplary embodiment, Figure 4 As shown, the cable partial discharge detection system also includes a signal acquisition device 40; the signal acquisition device 40 is connected to the sensor device 30 and the signal processing device 10; the signal acquisition device 40 is used to collect the discharge sensor signal detected by the sensor device 30, and transmit the discharge sensor signal to the signal processing device 10.

[0087] Specifically, the signal acquisition device 40 can collect signals. In this embodiment, the signal acquisition device 40 can collect the discharge sensing signal detected by the sensing device 30, and transmit the discharge sensing signal to the signal processing device 10 to ensure the normal operation of the cable partial discharge detection process.

[0088] In an exemplary embodiment, Figure 5 As shown, the cable partial discharge detection system further includes an alarm device 50; the alarm device 50 is used to detect the discharge intensity of the cable partial discharge, and feed back an alarm signal when the discharge intensity reaches a discharge threshold.

[0089] The discharge intensity reflects the amount of energy released during the discharge process within a specific period of time. The discharge threshold refers to a pre-set threshold of the discharge intensity.

[0090] Specifically, an alarm device 50 may be configured to detect the discharge intensity of partial discharge of the cable in real time. If the discharge intensity reaches a discharge threshold, it indicates that the discharge intensity is relatively strong and intervention is required, and an alarm signal needs to be fed back.

[0091] In this embodiment, an alarm device 50 is configured to detect the discharge intensity of partial discharge of the cable and to feed back an alarm signal when the discharge intensity reaches a discharge threshold. This can avoid cable damage caused by excessive partial discharge intensity and ensure normal cable partial discharge detection.

[0092] In an exemplary embodiment, Figure 6 As shown, the cable partial discharge detection system also includes a power supply device 60; the power supply device 60 is connected to the sensor device 30, the signal processing device 10, and the signal analysis device 20; the power supply device 60 is used to supply power to the sensor device 30, the signal processing device 10, and the signal analysis device 20.

[0093] The power supply device 60 may refer to a device that can supply power.

[0094] Specifically, in this embodiment, the power supply device 60 is connected to the sensing device 30 , the signal processing device 10 , and the signal analyzing device 20 , and can provide power to the sensing device 30 , the signal processing device 10 , and the signal analyzing device 20 .

[0095] In this embodiment, the power supply device 60 is designed with multiple redundancies to ensure continuous operation in the event of power failure or fluctuation.

[0096] In an exemplary embodiment, Figure 7 As shown, the cable partial discharge detection system further includes a display device 70 ; the display device 70 is connected to the sensor device 30 ; the display device 70 is used to obtain and display the discharge sensor signal from the sensor device 30 .

[0097] The display device 70 refers to a device having a display screen and capable of displaying information.

[0098] Specifically, in order to facilitate the technicians to timely understand the specific situation of the partial discharge detection, a display device 70 can be configured, and the display device 70 can obtain the discharge sensing signal from the sensing device 30 and display it on the display screen of the display device 70 .

[0099] In this embodiment, a device with a display screen that can display information is configured to facilitate technicians to understand the specific situation of partial discharge detection in a timely manner.

[0100] In an exemplary embodiment, Figure 8 As shown, the cable partial discharge detection system further includes a report generating device 80; the report generating device 80 is used to generate a discharge monitoring report of the cable partial discharge based on the discharge result.

[0101] The report generating device 80 may be used to generate a report.

[0102] Specifically, the report generating device 80 can generate a monitoring report of cable partial discharge based on the discharge results, provide historical data analysis, and assist maintenance personnel in fault prediction and decision support.

[0103] In an exemplary embodiment, Fig. 9 As shown, the cable partial discharge detection system also includes a discharge evaluation device 90; the discharge evaluation device 90 is connected to the signal processing device 10; the discharge evaluation device 90 is used to extract signal characteristics of the discharge processing signal to obtain signal characteristic parameters; based on the signal characteristic parameters, the discharge position and discharge intensity of the partial discharge are evaluated.

[0104] The discharge evaluation device 90 can specifically evaluate the discharge condition. The signal characteristic parameter refers to a parameter that can represent the signal characteristic.

[0105] Specifically, the discharge evaluation device 90 can extract signal features from the discharge processing signal to obtain signal feature parameters, and evaluate the discharge intensity and discharge position of the partial discharge through a mathematical model to provide data support for subsequent fault diagnosis.

[0106] In a specific embodiment, Fig.10 As shown, a cable partial discharge detection method is provided, which can be implemented by a cable partial discharge detection system. The system includes a sensor device 30, a data acquisition and processing device, and an alarm device 50. The core component is the sensor device 30, which integrates a fiber optic current sensor, an electromagnetic coupling sensor, an ultrasonic sensor, and an infrared sensor.

[0107] Fiber Optic Current Transformer (FOCT) is a device that uses optical fiber technology to measure current and is widely used in cable partial discharge (PD) detection. Its core mechanism and detailed introduction are as follows: Core Mechanism Measurement Principle: Fiber Optic Current Transformer is mainly based on the Faraday Effect, which means that the polarization state of light in the optical fiber will change under the action of an external magnetic field.

[0108] When current passes through a conductor, a magnetic field is generated around it. Fiber-optic current transformers use this principle to detect changes in the magnetic field generated by current through light propagation inside the optical fiber. Signal conversion: When the light beam in the fiber-optic sensor passes through a magnetic field, its polarization state changes due to the Faraday effect. By measuring the change in the polarization state of light, a signal proportional to the current can be obtained.

[0109] After conditioning, this signal can be used to analyze partial discharge conditions inside the cable.

[0110] Optical fiber: Usually specially designed optical fiber is used, which has good anti-interference and high sensitivity. Polarization controller: It is used to adjust the polarization state of the light beam in the optical fiber to improve the measurement accuracy.

[0111] Optical sensor: A device that converts optical signals into electrical signals, usually composed of photodetectors. Signal processing module: Responsible for filtering, amplifying, sampling and converting the detected signals for subsequent data analysis. High precision: Fiber optic current transformers have superior measurement accuracy and can accurately measure weak current changes in high voltage environments. Strong anti-interference ability: Because it is based on fiber optic technology, fiber optic current transformers are not subject to electromagnetic interference and are suitable for use in complex electromagnetic environments. High safety: The optical fiber itself is non-conductive, has high safety, and can operate in high voltage and high current environments. Fast response speed: It can respond to current changes in real time and is suitable for rapid detection of partial discharge signals. In cable partial discharge detection, fiber optic current transformers can effectively capture weak current changes caused by partial discharge, and provide comprehensive cable health status monitoring by combining with other sensors (such as electromagnetic coupling sensors, ultrasonic sensors, etc.). Therefore, for fiber optic sensors, the key is to have effective interference suppression capabilities and accurate partial discharge signal extraction technology to ensure the accuracy and reliability of the test results. During the field test, the high-frequency through-type current transformer was accurately placed on the grounding down conductor of the metal shielding layer at the end of the cable. When partial discharge occurs inside the cable, the generated pulse current will act on the metal shielding layer due to electromagnetic induction. Subsequently, the current is conducted to the ground through the grounding wire, and the current changes in this process can be captured and monitored by the optical fiber sensor.

[0112] Electromagnetic coupling sensors are specially designed to detect ultra-high frequency electromagnetic wave signals generated by partial discharge. Electromagnetic coupling sensors play a vital role in cable partial discharge (PD) detection. They use the changes in the electromagnetic field around the cable to monitor partial discharge. Partial discharge generates high-frequency pulse currents in power cables, which will generate instantaneous electromagnetic radiation in the surrounding area. Electromagnetic coupling sensors can capture these signals to monitor partial discharge.

[0113] Core Mechanism Principle of electromagnetic induction: Partial discharge generates high-frequency current pulses in the cable, which form an electromagnetic field around the cable.

[0114] Electromagnetic coupling sensors capture the high-frequency signals generated by partial discharge by sensing these electromagnetic waves. The sensors are usually placed on the surface of the cable or close to the cable to sense the partial discharge pulse current flowing through the cable and the electromagnetic radiation generated.

[0115] High-frequency response capability: Electromagnetic coupling sensors are particularly sensitive to high-frequency signals generated by partial discharge, because partial discharge often produces transient, high-frequency pulse signals.

[0116] The frequency range of these signals is usually from tens of megahertz (MHz) to hundreds of megahertz (MHz), and electromagnetic coupling sensors separate useful discharge signals from background noise through selective filtering.

[0117] Coupling mechanism: The sensor is usually non-contact coupled to the cable through capacitance or inductance, that is, the sensor does not need to be directly connected to the cable conductor, but obtains the electromagnetic radiation signal through induction.

[0118] Capacitive coupling is suitable for detecting electric field changes caused by partial discharge, while inductive coupling is mainly used to sense magnetic field changes caused by partial discharge.

[0119] Structure composition:

[0120] Coupling device: The electromagnetic coupling sensor can be designed as a ring or clip-on structure, which is placed on the surface of the cable to capture electromagnetic signals in a non-contact manner. Common structures include loop antennas, inductor coils, etc. Amplifier circuit: Since the amplitude of the partial discharge signal is small, the electromagnetic coupling sensor integrates an amplifier circuit to amplify the captured weak signal for subsequent processing. Filter: In order to remove low-frequency noise or interference in the environment, the sensor usually has a built-in bandpass filter to selectively amplify and extract the high-frequency signal of partial discharge.

[0121] Signal conditioning unit: further processes the signal, including denoising and smoothing, to improve the signal-to-noise ratio and ensure that the system can accurately determine the partial discharge situation.

[0122] Working principle: When local discharge occurs, high-frequency pulse current flows in the cable, generating short-term electromagnetic field fluctuations. The electromagnetic coupling sensor converts the high-frequency pulse signal into a voltage signal by sensing these electromagnetic waves. After amplification and filtering, these signals are transmitted to the data acquisition module for analysis.

[0123] Non-contact monitoring: The electromagnetic coupling sensor does not need to directly contact the cable conductor, is easy to install, and is suitable for cable systems of various types and voltage levels.

[0124] Wide-band response: The sensor has good sensitivity to high-frequency signals of partial discharge, can capture transient discharge events, and has a wide frequency range to adapt to different types of partial discharge.

[0125] Anti-electromagnetic interference: Since the frequency of the partial discharge signal is significantly different from the background power frequency power signal, the electromagnetic coupling sensor can effectively suppress the power frequency interference through filtering and obtain a clear discharge signal.

[0126] Partial discharge signals are usually sudden and random. Electromagnetic coupling sensors can capture these short-term discharge events through their high-frequency response characteristics. The sensor can continuously monitor the working status of the cable and detect the frequency and intensity changes of partial discharge in real time, thereby helping to predict and prevent cable failures. It is suitable for on-site monitoring and online monitoring, especially during the operation of the cable system, and can monitor the health status of the cable in real time without power outages.

[0127] When partial discharge occurs in a cable, ultra-high frequency electromagnetic waves with a frequency of hundreds of megahertz are generated. Ultra-high frequency sensors receive these electromagnetic wave signals and convert them into electrical signal outputs for subsequent signal processing and analysis. Ultra-high frequency sensors usually use antenna structures, such as microstrip antennas and helical antennas, to improve the receiving sensitivity and directionality of ultra-high frequency electromagnetic waves. After amplification, filtering and other processing, the output signal of the sensor can be used for the detection, location and analysis of partial discharge.

[0128] Ultrasonic sensors are based on the properties of ultrasound and are used to perform various functions such as distance measurement, object detection, and other measurement tasks. Ultrasonic sensors, a type of acoustic emission device based on the piezoelectric effect, work on the principle of transmitting ultrasonic pulses to a target object and subsequently receiving echo signals reflected by the object. The piezoelectric crystal inside its sensor generates ultrasonic waves under the stimulation of electrical signals. These ultrasonic waves propagate in the air or other media and are reflected back after encountering the target object. After receiving the reflected echo, the sensor converts it into an electrical signal and calculates the distance to the target object by measuring the time difference between transmission and reception. The operating bandwidth of the sensor covers the frequency band of 20 to 180 kHz. The sensitivity parameter is set to 85 dB (-75 dB). The output result is presented as a differential signal. This amplifier is a voltage type, and its structure includes an integrated design of a two-stage amplifier and a fourth-order high-pass filter. The main reason is that the detected signal is often extremely weak, and the intensity may be as low as microvolts or even lower. Only after multiple stages of amplification can the signal meet the standard requirements of data acquisition and processing. Infrared sensor: monitors the temperature fluctuation of the cable in real time, has fast response characteristics, and can feedback temperature changes within 0.1 seconds; uses non-contact temperature measurement technology, suitable for high voltage and high temperature environments, and reduces measurement errors; has automatic calibration function to ensure measurement accuracy in long-term use; can set multiple thresholds to adapt to different monitoring needs and improve safety.

[0129] Signal acquisition: Use a high-speed data acquisition card or a dedicated acquisition device to collect the electrical signal output by the sensor. The acquisition system needs to have a sufficiently high sampling frequency and resolution to ensure that the characteristics of the partial discharge signal can be accurately obtained. At the same time, in order to improve the reliability and anti-interference ability of the system, isolation, filtering and other technologies are usually used to pre-process the collected signals. Signal processing: For the collected partial discharge signals, the corresponding processing flow is implemented to extract key information. Common signal processing technologies cover multiple key links such as filtering, amplification, denoising and feature extraction. Taking digital filters as an example, their application is to filter signals and effectively eliminate high-frequency noise and low-frequency interference. At the same time, the amplitude of the signal is increased with the help of signal amplification technology, laying the foundation for subsequent analysis and processing. Wavelet transform, Fourier transform and other methods are used to extract the characteristics of the signal to obtain the amplitude, frequency, phase and other characteristic parameters of the partial discharge.

[0130] The schematic diagram of the cable insulation detection device is as follows: Fig.10 As shown. The present invention provides a cable partial discharge detection device and method, which are intended to accurately monitor and evaluate the partial discharge phenomenon inside the cable. The device integrates four core sensors: optical fiber current sensor, electromagnetic coupling sensor, ultrasonic sensor and infrared sensor, which are respectively used to capture the pulse current, electromagnetic radiation, mechanical vibration (sound wave) and temperature fluctuation generated by the partial discharge of the cable. Through the coordinated work of these sensors, the system can realize multi-dimensional monitoring of cable partial discharge in a complex power system, thereby improving the reliability and safety of the power system. The following are the detailed implementation steps of this embodiment:

[0131] The overall structure of the cable partial discharge detection system mainly includes the following modules:

[0132] Sensor device 30: responsible for real-time perception of different physical quantities generated by partial discharge phenomena.

[0133] The signal acquisition device 40 and the signal processing device 10 perform high-speed sampling, signal conditioning and data analysis on the signals acquired by the sensor.

[0134] Display device 70 and alarm device 50: display the processed data in real time and send out an alarm signal when an abnormality is detected.

[0135] Sensing device 30:

[0136] Fiber Optic Current Transformer (FOCT):

[0137] The fiber optic current transformer is one of the core components of this system, which is specially used to detect the current pulses generated by partial discharge in the cable. Its working principle is based on the Faraday effect, that is, when the current passes through the cable, the surrounding magnetic field acts on the light waves in the optical fiber, causing the polarization state of the light waves to change.

[0138] Implementation steps:

[0139] Optical fiber placement: The optical fiber is laid around the cable to ensure that it can capture the magnetic field changes generated around the cable. Light polarization measurement: When the local discharge generates a current pulse, the magnetic field around the cable will change due to the current fluctuation, causing the polarization angle of the light wave in the optical fiber to change. At this time, the sensor obtains the current signal by detecting the change in the polarization angle of the light wave.

[0140] Signal conversion and processing: The optical signal is converted into an electrical signal through an optical detector, and filtered, amplified and analyzed in the signal processing module to extract the characteristic current signal related to partial discharge.

[0141] Fiber optic current transformers have the advantages of high precision, strong anti-electromagnetic interference ability, and fast response speed. They are particularly suitable for real-time online monitoring of cable partial discharge.

[0142] Electromagnetic coupling sensor:

[0143] Electromagnetic coupling sensors are used to capture ultra-high frequency electromagnetic wave signals generated during partial discharge. Partial discharge generates high-frequency pulse currents in power cables, which generate instantaneous electromagnetic radiation around the cables. Electromagnetic coupling sensors sense these pulse signals by coupling the electromagnetic field of the cables.

[0144] Implementation steps:

[0145] Sensor installation: Place the electromagnetic coupling sensor on the surface of the cable, or non-contactly couple the cable electromagnetic field through capacitance or inductance. The sensor usually adopts a ring or clamp design, which is convenient for installation on the surface of the cable.

[0146] Signal capture: When local discharge occurs, high-frequency electromagnetic pulses spread from the surface of the cable, and the sensor captures the signal by sensing the electromagnetic waves around the cable.

[0147] Signal processing: The captured high-frequency electromagnetic wave signal is amplified by the amplifier inside the sensor, and the low-frequency noise is removed by a bandpass filter to extract the high-frequency partial discharge signal.

[0148] Electromagnetic coupling sensors are non-contact and highly sensitive, making them suitable for on-site monitoring of partial discharges and capable of online monitoring without affecting the normal operation of the cable.

[0149] Ultrasonic Sensors:

[0150] Partial discharge is accompanied by mechanical vibrations inside the cable, which propagate in the solid medium in the form of ultrasonic waves. Ultrasonic sensors use the piezoelectric effect to capture these sound wave signals generated by partial discharge.

[0151] Implementation steps:

[0152] Sensor installation: The ultrasonic sensor is installed on the outside of the cable and senses the mechanical vibration caused by partial discharge through the piezoelectric crystal.

[0153] Signal capture: The acoustic wave signal generated by partial discharge is converted into an electrical signal by a piezoelectric crystal. The multi-stage amplifier and filter integrated in the sensor can amplify the weak acoustic wave signal and remove irrelevant background noise.

[0154] Signal processing: The ultrasonic signal is amplified and filtered before being transmitted to the data processing module. The characteristic information of partial discharge, such as signal amplitude and frequency, is extracted through time domain and frequency domain analysis.

[0155] Ultrasonic sensors are suitable for monitoring mechanical vibrations generated by partial discharges either in situ or online and can provide additional information on partial discharge activity.

[0156] Infrared sensor:

[0157] The local temperature rise is usually accompanied by partial discharge. The infrared sensor monitors the temperature change caused by discharge by detecting the infrared radiation on the cable surface.

[0158] Implementation steps:

[0159] Sensor installation: Install the infrared sensor on the outside of the cable in a non-contact manner to directly sense the infrared radiation on the cable surface.

[0160] Temperature detection: Infrared sensors monitor temperature fluctuations on the cable surface in real time. When local discharge occurs, the local temperature rises and the sensor can quickly capture this temperature change.

[0161] Signal feedback: The sensor has an automatic calibration function and can provide real-time feedback on temperature changes based on preset thresholds, and issue an alarm signal when the temperature exceeds the threshold.

[0162] Infrared sensors can monitor the heat changes generated during partial discharge in real time and provide temperature data to assist in determining the health status of the cable.

[0163] Data collection and processing:

[0164] The signals collected by the sensor are sampled by a high-speed data acquisition card and enter the signal processing module for processing and analysis.

[0165] Implementation steps:

[0166] High-speed sampling: The data acquisition card uses high-frequency sampling technology to accurately sample the original signal collected by the sensor. The sampling system must have a sufficiently high sampling frequency and resolution to ensure accurate capture of partial discharge signals.

[0167] Signal processing: After the collected signals are pre-processed by filtering, amplification, and denoising, the system uses algorithms such as Fourier transform and wavelet transform to analyze the signals in the time domain and frequency domain to extract key information such as the amplitude, frequency, and phase of the partial discharge signal.

[0168] Feature extraction: After signal processing, the system will extract the characteristic parameters of partial discharge and evaluate the intensity and location of partial discharge through mathematical models to provide data support for subsequent fault diagnosis.

[0169] Real-time monitoring and alarm:

[0170] The present invention is equipped with a real-time monitoring and alarm module. When partial discharge is detected inside the cable and the discharge intensity reaches a preset threshold, the system automatically sends an alarm signal to prompt the operation and maintenance personnel to carry out maintenance.

[0171] Implementation steps:

[0172] Data visualization: The partial discharge status of the cable is displayed in real time on the display screen. The waveform, spectrum diagram and other data of the discharge signal are presented intuitively, making it easier for operation and maintenance personnel to judge the operating status of the cable.

[0173] Alarm triggering: The system has preset an alarm threshold for the partial discharge signal. When the discharge signal is detected to exceed the threshold, the alarm device 50 immediately sends out an audible and visual alarm signal to remind the maintenance personnel to take measures.

[0174] FPGA (signal analysis device 20) integrates the signals collected by different sensors according to the weights through the data weighted fusion algorithm to eliminate the errors that may be caused by a single sensor. According to the signal characteristic parameters detected by each sensor, FPGA performs cross-validation to ensure the accuracy and consistency of the partial discharge signal. Based on the analysis results, FPGA generates comprehensive partial discharge diagnostic information to provide a basis for subsequent decision-making and fault warning. In addition to signal processing, FPGA is also responsible for the real-time control and alarm functions of the system. When the partial discharge signal exceeds the preset threshold, FPGA can immediately trigger an alarm to notify the operation and maintenance personnel to take measures. In addition, FPGA can also dynamically adjust the sensor sampling frequency or detection mode according to the detected partial discharge situation.

[0175] FPGA monitors the characteristic parameters of each channel signal in real time. When the amplitude or frequency of the local discharge exceeds the set safety threshold, FPGA immediately sends out an alarm signal. Through the logic control circuit, FPGA controls the activation of the alarm device 50 (such as an audible and visual alarm) and can send the alarm information to the remote monitoring system. FPGA can dynamically adjust the data acquisition frequency. For example, when the intensity of the local discharge signal is small, the sampling rate is reduced to save resources; when the local discharge activity is frequent, the sampling rate is increased for more detailed monitoring. Advantages of FPGA High-speed parallel processing: FPGA has hardware parallel processing capabilities and can process real-time signals from multiple sensors at the same time, which is suitable for complex, multi-sensor system applications.

[0176] Low latency: The logic circuit design of FPGA makes its processing latency very low, which can meet the real-time requirements of partial discharge signal detection.

[0177] Flexibility: FPGA can dynamically configure internal logic circuits according to needs, adapt to different signal processing requirements, and can be quickly deployed and upgraded on site.

[0178] Resource saving: FPGA has powerful data compression and processing capabilities, which reduces the pressure of data transmission and storage and improves the overall efficiency of the system.

[0179] This system integrates a variety of advanced sensor technologies and can conduct all-round, multi-dimensional real-time monitoring of cable partial discharge phenomena. Fiber optic current sensors, electromagnetic coupling sensors, ultrasonic sensors and infrared sensors monitor partial discharge signals from four different physical angles: current, electromagnetic waves, sound waves and temperature, which greatly improves the sensitivity and accuracy of detection.

[0180] In a specific embodiment, a cable partial discharge detection system is also provided, characterized in that the device comprises:

[0181] Sensing device, the module integrates the following four sensor components: Fiber optic current sensor:

[0182] Adopting optical fiber technology, non-contact current measurement, suitable for high voltage environment, ensuring safety;

[0183] It has high precision and high sensitivity, can detect tiny current changes, and has strong anti-electromagnetic interference ability; through optical fiber signal transmission, it reduces the impact of electromagnetic interference on the measurement results;

[0184] It can support optical fibers of multiple wavelengths to meet different measurement requirements.

[0185] Electromagnetic coupling sensor: monitors electromagnetic radiation around the cable in real time, and captures electromagnetic signals caused by partial discharge through a dedicated coupling mechanism; uses an adaptive filtering algorithm to dynamically adjust filtering parameters to improve signal stability and accuracy; can detect electromagnetic radiation in a wide frequency band and adapt to a variety of working environments;

[0186] Equipped with a design for isolation and protection to reduce the interference of external electromagnetic noise on the measurement.

[0187] Ultrasonic sensor: used to detect ultrasonic signals inside the cable, and can accurately identify the characteristic frequency of partial discharge through spectrum analysis; uses a high-sensitivity microphone, can detect tiny changes in sound waves, and has multi-channel receiving capabilities; has high-frequency response capabilities, and can monitor the physical state and health of the cable in real time; has a certain temperature compensation capability to ensure accuracy under different ambient temperatures.

[0188] Infrared sensor: monitors the temperature fluctuation of the cable in real time, has fast response characteristics, and can feedback temperature changes within 0.1 seconds; uses non-contact temperature measurement technology, suitable for high voltage and high temperature environments, and reduces measurement errors; has automatic calibration function to ensure measurement accuracy in long-term use; can set multiple thresholds to adapt to different monitoring needs and improve safety.

[0189] The signal processing device includes:

[0190] Signal amplifier, used to amplify weak signals from sensors to ensure that the signal strength is suitable for subsequent processing;

[0191] The filter uses a combination of digital filtering and analog filtering to remove high-frequency noise and low-frequency interference signals;

[0192] The denoiser, combined with multiple denoising algorithms, can effectively eliminate the influence of environmental noise and improve the clarity and usability of the signal.

[0193] The signal analysis device has the following functions:

[0194] FPGA (field programmable gate array) design has high parallel processing capabilities and can process signals from multiple sensors simultaneously to achieve real-time data acquisition; low-latency response capability, fast signal filtering and Fourier transform, and accurate extraction of partial discharge characteristic signals; signal processing algorithms, including fast Fourier transform (FFT), wavelet transform, etc., are suitable for analysis and feature extraction of different types of signals; data storage unit is used to store monitoring data in real time, and has historical data query and playback functions to facilitate subsequent analysis and report generation.

[0195] The display device and alarm device have the following functions:

[0196] Real-time data display interface, which displays real-time monitoring data from various sensors through a graphical interface, including current value, electromagnetic radiation level, ultrasonic signal and temperature change, and supports multiple data display methods (such as charts, curves, etc.);

[0197] The alarm mechanism will sound and light alarms when abnormal partial discharge signals are detected or the temperature exceeds the preset range, and send alarm information to maintenance personnel through the network. It supports multiple alarm methods such as mobile phone text messages and emails; user-defined settings allow users to set alarm thresholds, data collection frequency and monitoring parameters according to actual needs.

[0198] The system supports wireless or wired network connection, enabling remote monitoring and data sharing, making it easier for maintenance personnel to conduct real-time diagnosis and processing.

[0199] The system can generate detailed monitoring reports, provide historical data analysis, and assist maintenance personnel in fault prediction and decision support.

[0200] The system is equipped with a variety of protection measures to adapt to high voltage and high temperature environments to ensure the safety and reliability of the equipment.

[0201] Each module of the system adopts a modular design to facilitate subsequent maintenance and upgrades, and supports the replacement and expansion of different sensors.

[0202] The system has good compatibility and can be integrated and interconnected with existing cable monitoring systems to improve the overall monitoring capabilities of the system.

[0203] The system's power supply unit is designed with multiple redundancies to ensure continuous operation in the event of power failure or fluctuations.

[0204] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0205] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A cable partial discharge detection system, characterized in that: The system includes a signal processing device, a signal analysis device, and at least two types of sensing devices; Each of the sensing devices is used to perform discharge detection on the cable in the case of partial discharge of the cable, and obtain at least two types of discharge sensing signals; The signal processing device is used to obtain each of the discharge sensor signals, and perform signal processing on each of the discharge sensor signals to obtain a discharge processing signal of each of the discharge sensor signals; The signal analysis device is used to perform signal analysis on each of the discharge processing signals based on the signal category of each of the discharge sensing signals, so as to determine the discharge result of the partial discharge of the cable.

2. The system according to claim 1, characterized in that The discharge sensing signal includes a fiber optic current signal, an electromagnetic signal, an ultrasonic signal, and an infrared signal; the sensing device includes a fiber optic current sensing module, an electromagnetic sensing module, an ultrasonic sensing module, and an infrared sensing module.

3. The system according to claim 1, characterized in that The signal processing device includes a signal enhancement module, a filtering module, and a denoising module.

4. The system according to claim 1, characterized in that The signal analysis device is specifically used for: determining a respective weight for each of the signal categories; Based on a data weighted fusion algorithm, signal integration is performed on each of the discharge processing signals according to each of the weights to determine a discharge comprehensive signal of the cable partial discharge; A discharge result of the partial discharge of the cable is determined based on the discharge comprehensive signal.

5. The system according to claim 1, characterized in that The system further comprises a signal acquisition device; the signal acquisition device is connected to the sensor device and the signal processing device; The signal acquisition device is used to acquire the discharge sensor signal detected by the sensor device and transmit the discharge sensor signal to the signal processing device.

6. The system according to claim 1, characterized in that The system also includes an alarm device; The alarm device is used to detect the discharge intensity of the partial discharge of the cable, and feed back an alarm signal when the discharge intensity reaches a discharge threshold.

7. The system according to claim 1, characterized in that The system further comprises a power supply device; the power supply device is connected to the sensing device, the signal processing device, and the signal analyzing device; The power supply device is used to supply power to the sensing device, the signal processing device, and the signal analyzing device.

8. The system according to claim 1, characterized in that The system further comprises a display device; the display device is connected to the sensor device; The display device is used to obtain and display the discharge sensing signal from the sensing device.

9. The system according to claim 1, characterized in that The system also includes a report generating device; The report generating device is used for generating a discharge monitoring report of the cable partial discharge based on the discharge result.

10. The system according to claim 1, characterized in that The system further comprises a discharge evaluation device; the discharge evaluation device is connected to the signal processing device; The discharge evaluation device is used to extract signal characteristics of the discharge processing signal to obtain signal characteristic parameters; Based on the signal characteristic parameters, the discharge position and discharge intensity of the partial discharge are evaluated.

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