Power cable laying stress monitoring device

Abstract

The invention discloses a power cable laying stress monitoring device which comprises a stress sensing module, a signal processing module, a data transmission module and a power supply module. The stress sensing module adopts an integrated FBG (Fiber Bragg Grating) sensor array of a flexible mounting belt, and realizes non-damage coating of a cable with the diameter of 3-200mm through an adjustable fastening device; the signal processing module comprises a low-noise optical fiber amplifier and a self-adaptive noise reduction algorithm, and is used for realizing + / -0.5 mu epsilon strain resolution and 5ms dynamic response; the data transmission module adopts a multi-band 4G / 5G communication module and supports AES-256 encryption and edge calculation; and the power supply module adopts a solar energy-lithium iron battery hybrid power supply system to realize 30-day uninterrupted operation. Through collaborative design of the FBG sensing array and the flexible mounting belt, the device solves the problems of poor mounting adaptability, low precision, response lag and the like of a traditional stress monitoring device, and is particularly suitable for real-time stress monitoring in the power cable laying process.

Description

Technical Field

[0001] The present application relates to the technical field of power equipment monitoring, and in particular to a power cable laying stress monitoring device. Background Art

[0002] In modern power systems, the laying of power cables is a vital task. With the continuous growth of power demand and the increasing complexity of power grids, it is particularly important to ensure the safety, efficiency and high quality of the power cable laying process. For example, the patent application with publication number 202411127706.4 in the prior art discloses a power cable laying stress monitoring device, which is provided by arranging permanent magnets at both ends of the center shaft outside the pulley, and the outer surface of the center shaft is covered with an elastomer, and an upper bearing and a lower bearing are provided on the outer surface of the elastomer, and a strain gauge is provided on the outer surface of the elastomer between the bearings. The conductor rod is electrically connected to the Wheatstone bridge and the signal processing mechanism, and the strain gauge is deformed by applying pressure through the cable, causing the resistance of the Wheatstone bridge to change and convert it into a voltage signal output. However, the above prior art still has the following technical problems:

[0003] (1) Complex mechanical structure and poor installation adaptability: The device relies on the mechanical linkage of pulleys, bearings and elastic bodies. The matching of bearings and elastic bodies needs to be precisely adjusted during installation. It has poor adaptability to cable diameter and laying environment, especially in narrow or curved laying scenarios, where it is difficult to ensure stable contact. (2) Strain gauges are susceptible to environmental interference: The strain gauges are directly exposed to the surface of the elastic body and are affected by vibration, temperature changes and mechanical wear for a long time, which can easily lead to zero point drift or sensitivity reduction, and the monitoring accuracy decays over time. (3) Dynamic response hysteresis: The mechanical transmission path (bearing → elastic body → strain gauge) has inherent hysteresis, making it difficult to capture instantaneous stress mutations in cable laying in real time, affecting the timeliness of warnings for high-risk working conditions. (4) No self-powered optimization design: Although it is mentioned that "no additional power supply is required", the specific energy acquisition method is not specified. The permanent magnet may only be used for sensing rather than power supply. In reality, it still needs to rely on an external power supply, resulting in limited deployment flexibility. Summary of the Invention

[0004] To overcome the technical shortcomings of existing power cable stress monitoring devices, such as complex mechanical structures resulting in poor installation adaptability, strain gauges susceptible to environmental interference affecting monitoring accuracy, dynamic response lags that cannot capture transient stress changes, and reliance on external power supplies that limit deployment flexibility, the present application provides a power cable laying stress monitoring device, specifically including the following technical solutions:

[0005] The invention comprises a stress sensing module, comprising a flexible mounting belt and a plurality of fiber Bragg grating sensors arranged thereon, wherein the flexible mounting belt is wrapped around the outer surface of the cable through an adjustable fastening device and has a built-in tension feedback mechanism to dynamically adapt to changes in cable diameter;

[0006] A signal processing module comprising a photoelectric conversion unit, a signal amplification unit, a filtering unit, and a digital signal processing unit connected in sequence, wherein the digital signal processing unit has a built-in multi-physical field coupling compensation algorithm for eliminating the influence of ambient temperature fluctuations on the wavelength of the fiber Bragg grating sensor;

[0007] A wireless transmission module, integrating a multi-band communication unit, an encryption protocol processing unit, and an edge computing unit. The edge computing unit is equipped with a stress anomaly diagnosis algorithm for real-time processing of the strain data output by the digital signal processing unit.

[0008] The autonomous power supply module includes a solar power generation unit, an energy storage battery unit and a dynamic load management circuit. The dynamic load management circuit is connected to a maximum power point tracking controller to optimize the energy distribution between the solar power generation unit and the energy storage battery unit.

[0009] Preferably, a plurality of fiber Bragg grating sensor units arranged in a spiral pattern are embedded in the flexible mounting belt of the stress sensing module, and the axial direction of each fiber Bragg grating sensor unit forms an angle of 15° to 75° with the cable axis.

[0010] Preferably, the flexible mounting tape is a multi-layer composite structure, comprising a pressure-sensitive adhesive layer, a strain conduction layer, an optical fiber fixing layer and a protective outer layer arranged in sequence from the inside to the outside, the pressure-sensitive adhesive layer adopts an acrylate-based pressure-sensitive adhesive and has a micron-level concave-convex texture on the surface, and the strain conduction layer is composed of a directionally arranged carbon nanotube-silicone rubber composite material.

[0011] Preferably, the packaging structure of the fiber Bragg grating sensor includes a pressure-sensitive silicone layer in direct contact with the cable surface, an anisotropic carbon fiber woven mesh in the middle layer, and a polyimide flexible circuit board in the outer layer. The surface of the pressure-sensitive silicone layer is provided with a micro-protrusion array that matches the texture of the cable sheath. The warp fibers of the carbon fiber woven mesh are arranged at 30° to the axial direction of the optical fiber. The polyimide flexible circuit board is etched with a copper foil strain gauge with a serpentine trace.

[0012] Preferably, the fiber Bragg grating sensor is connected to the flexible mounting belt by microstructure coupling. The surface of the flexible mounting belt is provided with a V-groove array, the groove depth is 1 / 3 to 1 / 2 of the optical fiber diameter, and the groove bottom is coated with UV curing glue.

[0013] Preferably, the signal processing module further comprises a temperature compensation unit, and the temperature compensation unit comprises an embedded PT1000 platinum resistor array and a thermal-mechanical coupling finite element database.

[0014] Preferably, the signal processing module includes a multi-stage adaptive filtering network, which is composed of a cascade of a programmable band-stop filter and a dynamic notch filter. The cutoff frequency of the programmable band-stop filter is adjusted in real time according to the fundamental frequency vibration characteristics of the fiber Bragg grating sensor array. The dynamic notch filter deeply suppresses the specific harmonic interference generated by the cable laying machinery. A variable gain transimpedance amplifier is inserted between the filtering network and the 24-bit Σ-Δ analog-to-digital converter. The gain coefficient of the variable gain transimpedance amplifier is adjusted in 0.1dB steps by a digital potentiometer controlled by a microprocessor.

[0015] Preferably, a reference grating group is provided in the fiber Bragg grating sensor array, comprising three orthogonally arranged gratings, which are packaged in a constant temperature bath of the device body.

[0016] Preferably, the fiber Bragg grating sensor has a core structure with periodic refractive index modulation, and its grating region adopts an inclined writing method to form an inclined grating structure with an angle of 5° to 85° with the optical fiber axis. The period of the inclined grating structure is gradually distributed along the optical fiber axis and the period change rate is 0.1nm / cm to 5nm / cm.

[0017] Preferably, a wing-shaped structure of a shape-adaptive film supported by a superelastic nickel-titanium alloy skeleton is provided in the middle of the flexible mounting belt, and micro vortex generators are distributed on the edges of the wing-shaped structure.

[0018] Beneficial effects

[0019] 1. The stress sensing module of the present invention adopts a flexible mounting strap and an adjustable fastening device, which can be easily and quickly installed on power cables of different diameters without the need for complex modification or damage to the cables, greatly reducing the installation difficulty and construction costs.

[0020] 2. Utilizing a fiber Bragg grating sensor array as a stress sensing element, the system exhibits high sensitivity to stress changes, enabling accurate detection of even the smallest changes in cable stress. Furthermore, the meticulous design of the signal processing module further enhances signal processing accuracy and reliability, ensuring the accuracy of stress monitoring data.

[0021] 3. The data transmission module uses advanced wireless communication technology to transmit the stress data collected by the monitoring device to the remote monitoring center in real time. Operation and maintenance personnel can understand the stress status of the cable at any time, discover and deal with potential problems in a timely manner, and effectively improve the reliability and safety of power cable operation.

[0022] 4. The power module uses a combination of solar energy and lithium batteries, fully utilizing clean solar energy, reducing reliance on external power sources and lowering operating costs. Furthermore, the application of intelligent charging management circuitry improves energy efficiency and extends the operating time of the monitoring device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an overall processing flow chart of the present invention. DETAILED DESCRIPTION

[0024] Example 1

[0025] A power cable laying stress monitoring device comprises a stress sensing module, a signal processing module, a wireless transmission module and an autonomous power supply module; the stress sensing module comprises a flexible mounting belt, a fiber Bragg grating sensor, an adjustable fastening device and a tension feedback mechanism; the flexible mounting belt is annularly wrapped around the outer surface of the cable, and a fiber Bragg grating sensor is evenly distributed on its outer side; the two ends of the flexible mounting belt are circumferentially locked by a threaded connection structure of the adjustable fastening device; the tension feedback mechanism consists of two groups of symmetrically arranged spring force measuring units, which are respectively embedded in the inner layer structure of the flexible mounting belt to detect changes in cable diameter in real time and feed back to the drive motor of the adjustable fastening device; the signal processing module comprises a photoelectric sensor. The optical-to-electric conversion unit is connected to the fiber Bragg grating sensor through an optical fiber jumper. The signal amplification unit adopts a three-stage operational amplifier circuit. The filtering unit is configured as a bandpass filter. The digital signal processing unit has an embedded processor with a multi-physical field coupling compensation algorithm. The processor corrects the wavelength offset caused by ambient temperature fluctuations through a temperature compensation coefficient matrix. The wireless transmission module integrates a multi-band communication unit, an encryption protocol processing unit and an edge computing unit. The multi-band communication unit includes Lora and NB-IoT dual-mode radio frequency circuits, the encryption protocol processing unit adopts an AES-hardware encryption chip, and the edge computing unit is equipped with an ARM-based stress anomaly diagnosis algorithm. The system comprises a Cortex-M processor connected to a digital signal processing unit via an SPI bus; the autonomous power supply module comprises a solar power generation unit, an energy storage battery unit, a dynamic load management circuit and a maximum power point tracking controller; the solar power generation unit is composed of PERC monocrystalline silicon panels connected in series, the energy storage battery unit adopts a lithium iron phosphate battery cell pack, the dynamic load management circuit comprises an independently controlled Buck-Boost topology circuit, and the maximum power point tracking controller is connected to the dynamic load management circuit via an IC interface to adjust the charge and discharge power ratio between the solar power generation unit and the energy storage battery unit in real time.

[0026] Furthermore, the flexible mounting belt is embedded with a plurality of fiber Bragg grating sensor units arranged in a spiral pattern, and the axial direction of each fiber Bragg grating sensor unit forms an angle of 15° to 75° with the cable axis; the spirally arranged fiber Bragg grating sensor units can realize multi-angle stress detection, improve the comprehensiveness and accuracy of stress monitoring, and are particularly suitable for stress distribution measurement under cable bending or torsion conditions.

[0027] The flexible mounting tape is a multi-layer composite structure, including a pressure-sensitive adhesive layer, a strain-transmitting layer, an optical fiber fixing layer, and a protective outer layer, arranged in order from the inside out. The pressure-sensitive adhesive layer uses an acrylate-based pressure-sensitive adhesive and has a micron-scale concave-convex texture on the surface. The strain-transmitting layer is composed of an oriented carbon nanotube silicone rubber composite material.

[0028] In the multi-layer composite structure of the flexible mounting tape, the micron-scale concave-convex texture of the pressure-sensitive adhesive layer enhances the contact area and adhesion with the cable surface, the directional arrangement of the carbon nanotube silicone rubber composite material of the strain conduction layer improves the strain transfer efficiency, the optical fiber fixing layer ensures the accurate positioning of the fiber Bragg grating sensor, and the protective outer layer provides mechanical protection and environmental isolation, thereby improving the sensitivity and long-term stability of stress monitoring.

[0029] Furthermore, the packaging structure of the fiber Bragg grating sensor includes a pressure-sensitive silicone layer in direct contact with the cable surface, an anisotropic carbon fiber woven mesh in the middle layer, and a polyimide flexible circuit board in the outer layer. The surface of the pressure-sensitive silicone layer is provided with a micro-protrusion array that matches the texture of the cable sheath, the warp fibers of the carbon fiber woven mesh are cross-arranged at 30° to the axial direction of the optical fiber, and the polyimide flexible circuit board is etched with a serpentine copper foil strain gauge. In the packaging structure of the fiber Bragg grating sensor, the micro-protrusion array of the pressure-sensitive silicone layer enhances the frictional contact with the cable sheath, the 30° cross-arrangement of the anisotropic carbon fiber woven mesh optimizes the lateral strain transmission efficiency, and the serpentine copper foil strain gauge of the polyimide flexible circuit board realizes redundant monitoring of the fiber Bragg grating sensor, thereby improving the reliability and accuracy of stress measurement.

[0030] Furthermore, the fiber Bragg grating sensor and the flexible mounting belt are connected by a microstructure coupling method. A V-groove array is provided on the surface of the flexible mounting belt. The groove depth is 1 / 3 to 1 / 2 of the optical fiber diameter, and the bottom of the groove is coated with ultraviolet curing glue. The microstructure coupling method between the fiber Bragg grating sensor and the flexible mounting belt is realized by the V-groove array and ultraviolet curing glue. This structure improves the fixing stability of the fiber Bragg grating sensor, reduces signal attenuation during stress transfer, and enhances the sensor's anti-peeling ability in a dynamic strain environment.

[0031] Furthermore, the signal processing module also includes a temperature compensation unit, which includes an embedded PT1000 platinum resistor array and a thermal-mechanical coupling finite element database; the temperature compensation unit collects cable surface temperature distribution data in real time through the embedded PT1000 platinum resistor array, and reconstructs the temperature field in combination with the thermal-mechanical coupling finite element database, significantly improving the stress measurement accuracy of the fiber Bragg grating sensor under complex environmental temperature changes.

[0032] Furthermore, the signal processing module includes a photoelectric conversion unit, a signal amplification unit, a multi-stage adaptive filtering network and a digital signal processing unit; the multi-stage adaptive filtering network is composed of a cascade of a programmable band-stop filter and a dynamic notch filter, the cutoff frequency of the programmable band-stop filter is adjusted in real time according to the fundamental frequency vibration characteristics of the fiber Bragg grating sensor array, the dynamic notch filter deeply suppresses the specific harmonic interference generated by the cable laying machinery, and a variable gain transimpedance amplifier is inserted between the multi-stage adaptive filtering network and the Σ-Δ type analog-to-digital converter. The gain coefficient of the variable gain transimpedance amplifier is adjusted in 0.1dB steps by a digital potentiometer controlled by a microprocessor; the multi-stage adaptive filtering network effectively suppresses mechanical vibration interference during the cable laying process through the coordinated work of the programmable band-stop filter and the dynamic notch filter, while the precise adjustment of the variable gain transimpedance amplifier ensures the dynamic range of signal acquisition, significantly improving the accuracy and anti-interference ability of stress monitoring.

[0033] Furthermore, a reference grating group is provided in the fiber Bragg grating sensor array, comprising three orthogonally arranged gratings, which are encapsulated in a constant temperature bath of the device body; the three orthogonally arranged gratings of the reference grating group are encapsulated in the constant temperature bath, which can eliminate the influence of ambient temperature changes on the measurement results and improve the measurement accuracy and stability of the fiber Bragg grating sensor.

[0034] Example 2

[0035] A device for monitoring stress during the laying of a power cable, which differs from Example 1 in that the fiber Bragg grating sensor has a core structure with periodic refractive index modulation, and its grating region adopts an inclined writing method to form a slanted grating structure with an angle of 5° to 85° with the optical fiber axis, and the period of the slanted grating structure is gradually distributed along the optical fiber axis and the period change rate is 0.1nm / cm to 5nm / cm; the slanted grating structure of the fiber Bragg grating sensor and its gradually changing period distribution characteristics can effectively suppress the chirp effect of traditional fiber Bragg grating sensors when measuring bending stress, improve the measurement accuracy of complex stress states during cable laying, and enhance the sensor's ability to resolve stress components in different directions.

[0036] Furthermore, a wing-shaped structure of a shape-adaptive film supported by a superelastic nickel-titanium alloy skeleton is set in the middle of the flexible mounting belt, and micro vortex generators are distributed on the edge of the wing-shaped structure; the wing-shaped structure adapts to changes in cable diameters through the deformation ability of the superelastic nickel-titanium alloy skeleton, and the micro vortex generators distributed on its edge can effectively suppress the wind vibration effect and improve the measurement stability of the sensor in complex outdoor environments.

[0037] Although the above describes the specific implementation methods of the present disclosure, it does not limit the scope of protection of the present disclosure. Those skilled in the art should understand that based on the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. A power cable laying stress monitoring device, characterized in that: include: A stress sensing module comprising a flexible mounting belt and a plurality of fiber Bragg grating sensors mounted thereon, wherein the flexible mounting belt is wrapped around the outer surface of the cable via an adjustable fastening device and has a built-in tension feedback mechanism to dynamically adapt to changes in cable diameter; A signal processing module comprising a photoelectric conversion unit, a signal amplification unit, a filtering unit, and a digital signal processing unit connected in sequence, wherein the digital signal processing unit has a built-in multi-physical field coupling compensation algorithm for eliminating the influence of ambient temperature fluctuations on the wavelength of the fiber Bragg grating sensor; A wireless transmission module, integrating a multi-band communication unit, an encryption protocol processing unit, and an edge computing unit. The edge computing unit is equipped with a stress anomaly diagnosis algorithm for real-time processing of the strain data output by the digital signal processing unit. The autonomous power supply module includes a solar power generation unit, an energy storage battery unit and a dynamic load management circuit. The dynamic load management circuit is connected to a maximum power point tracking controller to optimize the energy distribution between the solar power generation unit and the energy storage battery unit.

2. A power cable laying stress monitoring device according to claim 1, characterized in that The flexible mounting belt of the stress sensing module is embedded with a plurality of fiber Bragg grating sensor units arranged in a spiral shape, and the axial direction of each fiber Bragg grating sensor unit forms an angle of 15° to 75° with the cable axis.

3. A power cable laying stress monitoring device according to claim 1, characterized in that The flexible mounting tape is a multi-layer composite structure, including a pressure-sensitive adhesive layer, a strain conduction layer, an optical fiber fixing layer and a protective outer layer arranged in sequence from the inside to the outside. The pressure-sensitive adhesive layer adopts an acrylate-based pressure-sensitive adhesive and has a micron-level concave-convex texture on the surface. The strain conduction layer is composed of a directionally arranged carbon nanotube-silicone rubber composite material.

4. A power cable laying stress monitoring device according to claim 1, characterized in that The packaging structure of the fiber Bragg grating sensor includes a pressure-sensitive silicone layer in direct contact with the cable surface, an anisotropic carbon fiber woven mesh in the middle layer, and a polyimide flexible circuit board in the outer layer. The surface of the pressure-sensitive silicone layer is provided with a micro-protrusion array that matches the texture of the cable sheath. The warp fibers of the carbon fiber woven mesh are arranged at 30° to the axis of the optical fiber. The polyimide flexible circuit board is etched with a copper foil strain gauge with a serpentine pattern.

5. A power cable laying stress monitoring device according to claim 1, characterized in that: The fiber Bragg grating sensor is connected to the flexible mounting belt by microstructure coupling. The surface of the flexible mounting belt is provided with a V-shaped groove array, the groove depth is 1 / 3 to 1 / 2 of the optical fiber diameter, and the groove bottom is coated with ultraviolet curing glue.

6. A power cable laying stress monitoring device according to claim 1, characterized in that: The signal processing module further comprises a temperature compensation unit, which comprises an embedded PT1000 platinum resistor array and a thermal-mechanical coupling finite element database.

7. A power cable laying stress monitoring device according to claim 1, characterized in that The signal processing module includes a multi-stage adaptive filtering network, which is composed of a cascade of a programmable band-stop filter and a dynamic notch filter. The cutoff frequency of the programmable band-stop filter is adjusted in real time according to the fundamental frequency vibration characteristics of the fiber Bragg grating sensor array. The dynamic notch filter deeply suppresses the specific harmonic interference generated by the cable laying machinery. A variable gain transimpedance amplifier is inserted between the filtering network and the 24-bit Σ-Δ analog-to-digital converter. The gain coefficient of the variable gain transimpedance amplifier is adjusted in 0.1dB steps by a digital potentiometer controlled by a microprocessor.

8. A power cable laying stress monitoring device according to claim 1, characterized in that: The fiber Bragg grating sensor array is provided with a reference grating group, which includes three orthogonally arranged gratings and is packaged in a constant temperature bath of the device body.

9. A power cable laying stress monitoring device according to claim 1, characterized in that The fiber Bragg grating sensor has a core structure with periodic refractive index modulation. Its grating region adopts an inclined writing method to form an inclined grating structure with an angle of 5° to 85° with the optical fiber axis. The period of the inclined grating structure is gradually distributed along the optical fiber axis and the period change rate is 0.1nm / cm to 5nm / cm.

10. A power cable laying stress monitoring device according to claim 1, characterized in that: A wing-shaped structure of a shape-adaptive film supported by a superelastic nickel-titanium alloy skeleton is provided in the middle of the flexible mounting belt, and micro vortex generators are distributed on the edge of the wing-shaped structure.

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