High-voltage cable multi-point temperature monitoring system based on fiber bragg grating

Abstract

The invention discloses a fiber grating-based high-voltage cable multipoint temperature monitoring system, which comprises a distributed temperature acquisition module, a fiber signal transmission module, a grating demodulation and processing module, an edge processing and intelligent identification module, a wireless communication and remote monitoring module and a multi-channel extensible framework, the distributed temperature acquisition module captures temperature changes and generates signals, the optical fiber signal transmission module transmits the signals to the demodulation module, the grating demodulation and processing module decodes the signals and calculates the temperature, and the edge processing and intelligent identification module carries out real-time analysis and early warning. And the wireless communication and remote monitoring module uploads the data to a cloud for further analysis and monitoring. According to the invention, a multi-point monitoring network is constructed through distributed FBG temperature points, and real-time temperature sensing of each key position of the cable is realized; and an edge calculation and intelligent identification module is adopted, so that the system response speed and early warning capability are improved, and the cloud data processing load is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of network communications, and in particular to a high-voltage cable multi-point temperature monitoring system based on optical fiber gratings. Background Art

[0002] As urban power grid loads increase, the operational safety of high-voltage cables becomes increasingly important. As a key factor affecting cable insulation aging and failure, accurate, real-time monitoring of temperature is crucial for intelligent cable operation and maintenance. Currently widely used solutions, such as thermocouples and resistance temperature sensors, suffer from complex installation, significant electromagnetic interference, and limited measurement points. In contrast, fiber Bragg gratings (FBGs) offer broad application prospects in high-voltage cable temperature monitoring due to their strong resistance to electromagnetic interference, high sensitivity, and ease of distributed deployment.

[0003] However, existing FBG monitoring systems generally have the following problems: low structural integration and difficulty adapting to complex wiring; limited number of monitoring points, which makes it impossible to achieve refined distributed monitoring; poor linkage between the system and the operation and maintenance platform, and weak early warning and data fusion capabilities. To this end, a high-voltage cable multi-point temperature monitoring system based on fiber Bragg gratings is proposed. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In response to the shortcomings of the existing technology, the present invention provides a high-voltage cable multi-point temperature monitoring system based on fiber grating, which solves the following common problems of existing FBG monitoring systems: low structural integration and difficulty in adapting to complex wiring; limited number of monitoring points and inability to achieve refined distributed monitoring; poor linkage between the system and the operation and maintenance platform, and weak early warning and data fusion capabilities.

[0006] (2) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a high-voltage cable multi-point temperature monitoring system based on fiber grating, including a distributed temperature acquisition module, a fiber grating signal transmission module, a grating demodulation and processing module, an edge processing and intelligent recognition module, a wireless communication and remote monitoring module, and a multi-channel scalable architecture;

[0008] Distributed temperature acquisition module: This module includes several Fiber Bragg Grating (FBG) temperature sensors, which are integrated into the sheath or gap of the high-voltage cable through a coupling structure and evenly distributed along the cable axis. Each FBG temperature point achieves high-precision sensing of the local temperature through the packaging structure and has environmental isolation performance to improve measurement stability.

[0009] Optical fiber signal transmission module: Single-mode optical fiber is used to connect all FBGs in series to the grating demodulation and processing module. The optical fiber laying path is designed according to the cable channel;

[0010] Grating demodulation and processing module: including broadband light source, wavelength division multiplexer, spectrum demodulator, equipped with high-precision wavelength demodulation algorithm, can collect FBG reflection wavelength in real time and convert it into temperature information;

[0011] The edge processing and intelligent recognition module uses an embedded processor to process temperature change data in real time at the acquisition end. It also has an embedded abnormal pattern recognition algorithm to quickly identify overheating risks on site and generate local warnings.

[0012] Wireless communication and remote monitoring module: Uploads processed data to the cloud monitoring platform via the NB-IoT / 5G module, supports integration with SCADA and EMS systems, and has the functions of actively pushing abnormal data and linking operation and maintenance work orders;

[0013] Multi-channel scalable architecture, the system supports multiple demodulation units in parallel, centralized management through the master gateway, and a single system can be expanded to 256 temperature measurement points to meet the needs of long-distance or multi-loop cable monitoring;

[0014] The distributed temperature acquisition module captures temperature changes and generates signals. The fiber optic signal transmission module transmits these signals to the demodulation module. The grating demodulation and processing module decodes the signals and calculates the temperature. The edge processing and intelligent recognition module performs real-time analysis and early warning. The wireless communication and remote monitoring module uploads the data to the cloud for further analysis and monitoring. The multi-channel scalable architecture provides the system with flexible expansion capabilities, supports the parallel operation of multiple distributed temperature acquisition modules and fiber optic signal transmission modules, and expands the monitoring range and capacity.

[0015] As a further preferred embodiment of the present invention, the structure of the distributed temperature acquisition module is as follows: each temperature measuring point adopts a Bragg grating (FBG) sensor, and the central wavelength is set in the 1550nm communication window range; the FBG sensor is laser engraved in the core diameter of the optical fiber and has stress-temperature dual sensitivity characteristics; the sensor packaging layer adopts ceramic coating, and each group of cable segments is configured with a number of temperature sensing points, the specific spacing is based on the layout length and key node settings, the accuracy error is ±0.1°C, and the response time is less than 1 second; the operating cable temperature range is -40-150°C.

[0016] As a further preferred embodiment of the present invention, the optical fiber signal transmission module uses low-loss single-mode optical fiber to reduce signal attenuation. The core diameter of the optical fiber is 9 μm, and the optical fiber transmission loss is less than 0.3 dB / km. For long-distance cables, optical fiber relay amplification nodes are designed to ensure complete signal transmission and reduce data loss, supporting transmission distances of more than 10 kilometers. The outer layer of the optical fiber is made of PE composite material with anti-electromagnetic interference (EMI) properties. The optical fiber support structure adopts an optical fiber support structure within a cable sheath or a pipe.

[0017] As a further preferred embodiment of the present invention, the grating demodulation and processing module adopts high-precision wavelength demodulation technology, wavelength demodulation accuracy, and uses spectrum analysis technology to perform high-precision demodulation on the wavelength reflected by the FBG, with a wavelength resolution of up to 0.01nm, thereby providing high-precision data with a temperature accuracy of ±0.1°C. It adopts multi-channel demodulation and is equipped with a multi-channel spectrum demodulator to support parallel processing of signals from multiple sensors to ensure the real-time performance of the system; it also includes data preprocessing and filtering, implementing time domain and frequency domain filtering technology to preprocess environmental noise and error signals in optical fiber transmission to eliminate noise interference on the data, using a calibrated algorithm to accurately match the reflected wavelength of the FBG with the temperature, and calculate the temperature change in real time; data synchronization and timing control, including time synchronization: using the Network Time Protocol (NTP) to uniformly timestamp the temperature data collected by each sensor to ensure the consistency of data collection, and timing processing: using timing control to process temperature data read by different sampling times and sensors to ensure smooth data transmission of the entire system.

[0018] As a further preferred embodiment of the present invention, the edge processing and intelligent identification module includes edge computing platform design, intelligent early warning and anomaly identification algorithm, and local data storage and fault backtracing. The hardware platform selection of the edge computing platform design: using an edge computing platform based on FPGA or embedded processor, computing power configuration: capable of data preprocessing, temperature trend analysis and anomaly detection, and real-time feedback of temperature change data; the intelligent early warning and anomaly identification algorithm includes, fast Fourier transform (FFT) algorithm: used to analyze the spectrum changes of temperature signals, identify temperature fluctuation trends, and issue alarms in time, neural network classifier: based on deep learning algorithm CNN or LSTM for historical data analysis, identify different temperature change patterns through training models, and predict potential overheating risks; local data storage and fault backtracing, locally save at least 72 hours of data, and design redundant storage architecture to ensure that the collected data will not be lost due to hardware failure.

[0019] As a further preferred embodiment of the present invention, the wireless communication and remote monitoring module supports NB-IoT, 5G, and Wi-Fi, uploads temperature data to the cloud platform through wireless communication, supports real-time monitoring, historical data backtracking, and temperature anomaly alarms, provides a standardized interface, and adopts MODBUS or MQTT protocol to integrate data with the power grid dispatching system and energy efficiency management system (EMS), sets multi-level alarms according to different temperature anomaly levels, and notifies operation and maintenance personnel via SMS, email, or APP push.

[0020] As a further preferred embodiment of the present invention, the multi-channel scalable architecture, its master gateway integrates data acquisition, demodulation, transmission and processing functions, is connected to the downstream demodulator via Ethernet and CAN bus communication, supports each demodulator to access up to 32 temperature points, and the system supports parallel demodulation and real-time data acquisition of up to 256 temperature measurement points. Each demodulation unit works independently and is centrally managed by the master gateway. It supports flexible expansion and can add new demodulators or sensors wirelessly or wired to meet the needs of long-distance cable or multiple loop monitoring. The system adopts a dual-channel redundant design and supports a fault isolation mechanism.

[0021] (3) Beneficial effects

[0022] The present invention provides a high-voltage cable multi-point temperature monitoring system based on fiber grating. It has the following beneficial effects:

[0023] Compared with the existing technology, the present invention has the following advantages: a multi-point monitoring network is constructed through distributed FBG temperature points to achieve real-time temperature perception of key positions of the cable; edge computing and intelligent identification modules are used to improve the system response speed and early warning capability, and reduce the cloud data processing load; it has modular and multi-channel expansion capabilities and is suitable for a variety of cable laying scenarios; it supports seamless connection with the smart grid system, and improves the overall operation and maintenance automation and visualization level.

[0024] This system features high-precision temperature monitoring, utilizing Fiber Bragg Grating (FBG) sensors for high-precision temperature measurement with an accuracy of ±0.1°C. It can monitor temperature changes in high-voltage cables in real time, providing stable and reliable data, particularly in complex environments. This is crucial for preventing cable failures caused by overheating. The system deploys multiple FBG sensors to achieve distributed temperature acquisition along the cable axis. Compared to traditional centralized temperature monitoring methods, distributed acquisition can precisely locate temperature changes, adapting to the monitoring needs of long-distance cables or multiple loop cables, significantly improving the comprehensiveness and accuracy of monitoring. It also offers strong anti-interference capabilities and adaptability to complex environments. Fiber transmission signals are unaffected by electromagnetic interference (EMI). Fiber itself exhibits excellent resistance to high temperatures, pressure, and moisture, making it suitable for long-term stable operation in harsh industrial environments. The system utilizes low-loss single-mode fiber, achieving a transmission loss of less than 0.3dB / km, supporting long-distance transmission over 10 kilometers and ensuring system reliability. Intelligent edge processing and early warning: The edge processing module is equipped with an embedded processor that combines fast Fourier transform (FFT) and deep learning algorithms (such as CNN or LSTM) to analyze temperature trends and identify anomalies in real time. This intelligent identification system can promptly detect potential overheating risks and generate local alerts, effectively preventing accidents. Remote monitoring and cloud data integration: The system uses wireless communication technologies such as NB-IoT / 5G to enable remote data transmission, uploading collected data to a cloud platform for real-time monitoring, historical data backtracking, and temperature anomaly alarms. Integration with SCADA, EMS, and other systems enables multi-system collaboration, improving overall monitoring capabilities. Anomaly information can be pushed to operations and maintenance personnel via SMS, email, and apps for rapid response to emergencies. Flexible expansion and multi-channel support: The system offers flexible scalability, supporting multiple demodulation units operating in parallel and centrally managed by a master control gateway. A single system can support concurrent demodulation of up to 256 temperature measurement points, adapting to large-scale cable monitoring. For monitoring long cables or multiple circuits, new demodulators or sensors can be added wirelessly or wired to meet the needs of different application scenarios. High reliability and redundancy design: The system adopts a dual-channel redundant design and supports fault isolation mechanism. It can ensure normal operation of the system in the event of hardware failure, avoiding the paralysis of the entire system due to single point failure. This high reliability design ensures the long-term stability of the system in critical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the system principle framework of the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] See also Figure 1 , an embodiment of the present invention provides a technical solution: a high-voltage cable multi-point temperature monitoring system based on fiber grating, including a distributed temperature acquisition module, an optical fiber signal transmission module, a grating demodulation and processing module, an edge processing and intelligent recognition module, a wireless communication and remote monitoring module, and a multi-channel scalable architecture;

[0028] Distributed temperature acquisition module: This module includes several Fiber Bragg Grating (FBG) temperature sensors, which are integrated into the sheath or gap of the high-voltage cable through a coupling structure and evenly distributed along the cable axis. Each FBG temperature point achieves high-precision sensing of the local temperature through the packaging structure and has environmental isolation performance to improve measurement stability.

[0029] Optical fiber signal transmission module: Single-mode optical fiber is used to connect all FBGs in series to the grating demodulation and processing module. The optical fiber laying path is designed according to the cable channel;

[0030] Grating demodulation and processing module: including broadband light source, wavelength division multiplexer, spectrum demodulator, equipped with high-precision wavelength demodulation algorithm, can collect FBG reflection wavelength in real time and convert it into temperature information;

[0031] The edge processing and intelligent recognition module uses an embedded processor to process temperature change data in real time at the acquisition end. It also has an embedded abnormal pattern recognition algorithm to quickly identify overheating risks on site and generate local warnings.

[0032] Wireless communication and remote monitoring module: Uploads processed data to the cloud monitoring platform via the NB-IoT / 5G module, supports integration with SCADA and EMS systems, and has the functions of actively pushing abnormal data and linking operation and maintenance work orders;

[0033] Multi-channel scalable architecture, the system supports multiple demodulation units in parallel, centralized management through the master gateway, and a single system can be expanded to 256 temperature measurement points to meet the needs of long-distance or multi-loop cable monitoring;

[0034] The distributed temperature acquisition module captures temperature changes and generates signals. The fiber optic signal transmission module transmits these signals to the demodulation module. The grating demodulation and processing module decodes the signals and calculates the temperature. The edge processing and intelligent recognition module performs real-time analysis and early warning. The wireless communication and remote monitoring module uploads the data to the cloud for further analysis and monitoring. The multi-channel scalable architecture provides the system with flexible expansion capabilities, supports the parallel operation of multiple distributed temperature acquisition modules and fiber optic signal transmission modules, and expands the monitoring range and capacity.

[0035] The structure of the distributed temperature acquisition module:

[0036] Each temperature measurement point uses a Bragg grating (FBG) sensor with a central wavelength set within the 1550nm communication window. The FBG sensor is laser-engraved into the core of the optical fiber and has stress-temperature dual sensitivity. The sensor packaging layer uses a ceramic coating, and each cable segment is equipped with several temperature sensing points. The specific spacing is based on the layout length and key nodes. The accuracy error is ±0.1°C and the response time is less than 1 second. The operating cable temperature range is -40-150°C.

[0037] The fiber optic signal transmission module uses low-loss single-mode optical fiber to reduce signal attenuation. The core diameter of the optical fiber is 9μm, and the optical fiber transmission loss is less than 0.3dB / km. For long-distance cables, optical fiber relay amplification nodes are designed to ensure complete signal transmission and reduce data loss, supporting transmission distances of more than 10 kilometers. The outer layer of the optical fiber is made of PE composite material with anti-electromagnetic interference (EMI) characteristics. The optical fiber support structure adopts an optical fiber support structure inside the cable sheath or pipe.

[0038] The grating demodulation and processing module adopts high-precision wavelength demodulation technology. The wavelength demodulation accuracy is high. Spectral analysis technology is used to demodulate the wavelength reflected by the FBG with high precision. The wavelength resolution can reach 0.01nm, thereby providing high-precision temperature data with an accuracy of ±0.1℃. Multi-channel demodulation is adopted and equipped with a multi-channel spectrum demodulator to support parallel processing of signals from multiple sensors to ensure the real-time performance of the system. It also includes data preprocessing and filtering, implementing time domain and frequency domain filtering technology to preprocess environmental noise and error signals in optical fiber transmission to eliminate noise interference on the data. A calibrated algorithm is used to accurately match the FBG reflection wavelength with temperature and calculate temperature changes in real time. Data synchronization and timing control include time synchronization: using the Network Time Protocol (NTP) to uniformly timestamp the temperature data collected by each sensor to ensure the consistency of data collection. Timing processing: using timing control to process temperature data read by different sampling times and sensors to ensure smooth data transmission of the entire system.

[0039] The edge processing and intelligent identification module includes edge computing platform design, intelligent early warning and anomaly identification algorithms, and local data storage and fault backtracing. The hardware platform selection for edge computing platform design: Use FPGA or embedded processor-based edge computing platform to build an edge computing platform. Computing power configuration: It can perform data preprocessing, temperature trend analysis and anomaly detection, and provide real-time feedback of temperature change data; intelligent early warning and anomaly identification algorithms include, Fast Fourier Transform (FFT) algorithm: used to analyze the spectral changes of temperature signals, identify temperature fluctuation trends, and issue alarms in time, neural network classifier: based on deep learning algorithms CNN or LSTM for historical data analysis, identify different temperature change patterns through training models, and predict potential overheating risks; local data storage and fault backtracing, save at least 72 hours of data locally, and design redundant storage architecture to ensure that the collected data will not be lost due to hardware failure.

[0040] The wireless communication and remote monitoring module supports NB-IoT, 5G, and Wi-Fi. It uploads temperature data to the cloud platform via wireless communication, supports real-time monitoring, historical data backtracking, and temperature anomaly alarms. It provides a standardized interface and uses MODBUS or MQTT protocols to integrate data with the power grid dispatching system and energy efficiency management system (EMS). It can set multi-level alarms based on different temperature anomaly levels and notify operation and maintenance personnel via SMS, email, or app push.

[0041] The multi-channel scalable architecture has a master gateway that integrates data acquisition, demodulation, transmission and processing functions. It connects to the downstream demodulator via Ethernet and CAN bus communication, supports up to 32 temperature points for each demodulator, and the system supports parallel demodulation and real-time data acquisition of up to 256 temperature measurement points. Each demodulation unit works independently and is centrally managed by the master gateway. It supports flexible expansion and can add new demodulators or sensors wirelessly or wired to meet the needs of long-distance cable or multiple loop monitoring. The system adopts a dual-channel redundant design and supports fault isolation mechanism.

[0042] Example 1: Application of high-voltage cable temperature monitoring system

[0043] This example demonstrates the application of this temperature monitoring system in a power transmission network, monitoring the temperature of a 15-kilometer-long high-voltage cable. The system uses fiber Bragg grating (FBG) sensors to monitor temperature at various locations along the cable (one temperature collection point every kilometer), ensuring safety during cable operation and promptly detecting overheating issues.

[0044] System Configuration:

[0045] Distributed temperature acquisition module:

[0046] 16 FBG sensors are deployed, evenly distributed on the sheath layer of the cable, with an interval of 1 km.

[0047] The central wavelength of each sensor is 1550nm, and it has stress-temperature dual sensitivity.

[0048] The temperature measurement accuracy is ±0.1°C and the response time is less than 1 second.

[0049] The sensor package uses ceramic coating and has a temperature measurement range of -40°C to 150°C.

[0050] The position of each sensor is precisely calibrated by laser engraving.

[0051] Fiber optic signal transmission module:

[0052] Low-loss single-mode optical fiber with a core diameter of 9 μm was used.

[0053] Optical fiber transmission loss is less than 0.3dB / km.

[0054] Design fiber optic relay amplification nodes to ensure no signal loss over transmission distances of more than 10 kilometers.

[0055] The outer layer of the optical fiber is made of PE composite material, which has anti-electromagnetic interference properties.

[0056] Grating demodulation and processing module:

[0057] High-precision wavelength demodulation technology, wavelength resolution reaches 0.01nm.

[0058] Multi-channel parallel demodulation is performed through the spectrum demodulator, supporting real-time data acquisition of up to 256 temperature points.

[0059] Demodulation accuracy: Temperature ±0.1℃.

[0060] Data preprocessing uses time domain and frequency domain filtering techniques to eliminate noise interference.

[0061] Edge processing and intelligent recognition module:

[0062] An FPGA-based embedded processing platform with computing power supporting fast Fourier transform (FFT) analysis and neural network pattern recognition (such as CNN or LSTM).

[0063] Intelligent early warning algorithms are used to identify abnormal temperature changes, predict overheating risks, and generate local alarms.

[0064] Local data storage function and redundant storage architecture ensure that data is retained for at least 72 hours.

[0065] Wireless communication and remote monitoring module:

[0066] Supports NB-IoT and 5G network transmission, uploading temperature data to the cloud monitoring platform.

[0067] Provides real-time monitoring, historical data backtracking, temperature anomaly alarm and operation and maintenance work order linkage functions.

[0068] Standardized data interfaces support integration with SCADA and EMS systems.

[0069] Multi-channel scalable architecture:

[0070] The master control gateway supports parallel demodulation and real-time data acquisition of up to 256 temperature points.

[0071] Each demodulation unit supports up to 32 temperature measurement points, supporting system expansion and equipment redundancy.

[0072] Dual-channel redundant design supports fault isolation mechanism to ensure high system availability.

[0073] The system performance parameter table is as follows:

[0074]

[0075]

[0076] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0077] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A high-voltage cable multi-point temperature monitoring system based on fiber Bragg grating, characterized by: It includes distributed temperature acquisition module, optical fiber signal transmission module, grating demodulation and processing module, edge processing and intelligent identification module, wireless communication and remote monitoring module, and multi-channel scalable architecture; Distributed temperature acquisition module: This module includes several Fiber Bragg Grating (FBG) temperature sensors, which are integrated into the sheath or gap of the high-voltage cable through a coupling structure and evenly distributed along the cable axis. Each FBG temperature point achieves high-precision sensing of the local temperature through the packaging structure and has environmental isolation performance to improve measurement stability. Optical fiber signal transmission module: Single-mode optical fiber is used to connect all FBGs in series to the grating demodulation and processing module. The optical fiber laying path is designed according to the cable channel; Grating demodulation and processing module: including broadband light source, wavelength division multiplexer, spectrum demodulator, equipped with high-precision wavelength demodulation algorithm, can collect FBG reflection wavelength in real time and convert it into temperature information; The edge processing and intelligent recognition module uses an embedded processor to process temperature change data in real time at the acquisition end. It also has an embedded abnormal pattern recognition algorithm to quickly identify overheating risks on site and generate local warnings. Wireless communication and remote monitoring module: Uploads processed data to the cloud monitoring platform via the NB-IoT / 5G module, supports integration with SCADA and EMS systems, and has the functions of actively pushing abnormal data and linking operation and maintenance work orders; Multi-channel scalable architecture, the system supports multiple demodulation units in parallel, centralized management through the master gateway, and a single system can be expanded to 256 temperature measurement points to meet the needs of long-distance or multi-loop cable monitoring; The distributed temperature acquisition module captures temperature changes and generates signals. The fiber optic signal transmission module transmits these signals to the demodulation module. The grating demodulation and processing module decodes the signals and calculates the temperature. The edge processing and intelligent recognition module performs real-time analysis and early warning. The wireless communication and remote monitoring module uploads the data to the cloud for further analysis and monitoring. The multi-channel scalable architecture provides the system with flexible expansion capabilities, supports the parallel operation of multiple distributed temperature acquisition modules and fiber optic signal transmission modules, and expands the monitoring range and capacity.

2. The high-voltage cable multi-point temperature monitoring system based on fiber Bragg grating according to claim 1, characterized in that: The distributed temperature acquisition module is structured as follows: each temperature measurement point uses a Bragg grating (FBG) sensor, with a central wavelength set within the 1550nm communication window range; the FBG sensor is laser-engraved into the optical fiber core diameter and has stress-temperature dual sensitivity characteristics; the sensor packaging layer uses a ceramic coating, and each group of cable segments is configured with several temperature sensing points, with specific spacing based on the layout length and key nodes. The accuracy error is ±0.1°C and the response time is less than 1 second; the operating cable temperature range is -40-150°C.

3. The fiber Bragg grating-based high-voltage cable multi-point temperature monitoring system according to claim 1, characterized in that: The optical fiber signal transmission module uses low-loss single-mode optical fiber to reduce signal attenuation. The core diameter of the optical fiber is 9μm, and the optical fiber transmission loss is less than 0.3dB / km. For long-distance cables, optical fiber relay amplification nodes are designed to ensure complete signal transmission and reduce data loss, supporting transmission distances of more than 10 kilometers. The outer layer of the optical fiber is made of PE composite material with anti-electromagnetic interference (EMI) characteristics. The optical fiber support structure adopts an optical fiber support structure inside a cable sheath or a pipe.

4. The fiber Bragg grating-based high-voltage cable multi-point temperature monitoring system according to claim 1, characterized in that: The grating demodulation and processing module adopts high-precision wavelength demodulation technology. The wavelength demodulation accuracy is high, and spectrum analysis technology is used to demodulate the wavelength reflected by the FBG with high precision. The wavelength resolution can reach 0.01nm, thereby providing high-precision data with a temperature accuracy of ±0.1°C. It adopts multi-channel demodulation and is equipped with a multi-channel spectrum demodulator to support parallel processing of signals from multiple sensors to ensure the real-time performance of the system. It also includes data preprocessing and filtering, implementing time domain and frequency domain filtering technology to preprocess environmental noise and error signals in optical fiber transmission to eliminate noise interference on the data. A calibrated algorithm is used to accurately match the reflected wavelength of the FBG with temperature and calculate temperature changes in real time. Data synchronization and timing control include time synchronization: using the Network Time Protocol (NTP) to uniformly timestamp the temperature data collected by each sensor to ensure consistency in data collection; timing processing: using timing control to process temperature data read by different sampling times and sensors to ensure smooth data transmission of the entire system.

5. The high-voltage cable multi-point temperature monitoring system based on fiber Bragg grating according to claim 1, characterized in that: The edge processing and intelligent identification module includes edge computing platform design, intelligent early warning and anomaly identification algorithm, and local data storage and fault backtracing. The hardware platform selection for the edge computing platform design: using an edge computing platform based on FPGA or embedded processor, computing power configuration: capable of data preprocessing, temperature trend analysis and anomaly detection, and real-time feedback of temperature change data; the intelligent early warning and anomaly identification algorithm includes, fast Fourier transform (FFT) algorithm: used to analyze the spectrum changes of temperature signals, identify temperature fluctuation trends, and issue alarms in time, neural network classifier: based on deep learning algorithm CNN or LSTM for historical data analysis, identify different temperature change patterns through training models, and predict potential overheating risks; local data storage and fault backtracing, locally save at least 72 hours of data, and design redundant storage architecture to ensure that the collected data will not be lost due to hardware failure.

6. The high-voltage cable multi-point temperature monitoring system based on fiber Bragg grating according to claim 1, characterized in that: The wireless communication and remote monitoring module supports NB-IoT, 5G, and Wi-Fi, uploads temperature data to the cloud platform via wireless communication, supports real-time monitoring, historical data backtracking, and temperature anomaly alarms, provides a standardized interface, and uses MODBUS or MQTT protocols to integrate data with the power grid dispatching system and energy efficiency management system (EMS). It sets multi-level alarms based on different temperature anomaly levels and notifies operation and maintenance personnel via SMS, email, or APP push.

7. The high-voltage cable multi-point temperature monitoring system based on fiber Bragg grating according to claim 1, characterized in that: The multi-channel scalable architecture has a master gateway that integrates data acquisition, demodulation, transmission and processing functions, connects to downstream demodulators via Ethernet and CAN bus communication, supports each demodulator to access up to 32 temperature points, and the system supports parallel demodulation and real-time data acquisition of up to 256 temperature measurement points. Each demodulation unit works independently and is centrally managed by the master gateway. It supports flexible expansion and can add new demodulators or sensors wirelessly or wired to meet the needs of long-distance cable or multiple loop monitoring. The system adopts a dual-channel redundant design and supports a fault isolation mechanism.

Images