Power transmission line defect sensing type composite insulator

Abstract

The invention discloses a power transmission line defect sensing type composite insulator which comprises an insulator body, a first fitting and a second fitting are arranged at the upper end and the lower end of the insulator body respectively, a sheath and an umbrella skirt are sequentially arranged outside a core rod of the insulator body, and a state sensing system and a wireless energy transmission system are integrated on the insulator body; the state sensing system is used for monitoring and analyzing an electric field, vibration and ultrasonic signals on the surface of the insulator in real time so as to realize identification and positioning of internal defects; and the wireless energy transmission systems are distributed at intervals in the axial direction of the insulator body and used for transmitting electric energy between the high-voltage end and the low-voltage end in a non-contact mode through a magnetic resonance coupling mode and providing continuous electric power supply for the state sensing system. The problems that internal defects of an existing composite insulator are difficult to find in time, a high-voltage side sensing unit cannot stably supply power for a long time, and long-term operation reliability is insufficient are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulators, in particular to a power transmission line defect sensing type composite insulator. BACKGROUND

[0002] Composite insulators have been widely used in modern power grids due to their light weight, high strength, and good pollution flashover resistance. However, as the operation time increases, the risk of failure caused by internal defects such as core rod cracking, interface debonding, and moisture absorption is increasingly prominent, seriously threatening the safety of power grids.

[0003] Currently, the state monitoring of composite insulators mainly relies on periodic manual inspection and offline testing. Common techniques include infrared temperature measurement, ultraviolet imaging, and hydrophobicity detection. These methods have obvious limitations: first, they are indirect and offline detection methods, which cannot achieve continuous online monitoring and are difficult to detect sudden defects in time; second, they are easily affected by environment, light, and weather, with limited detection accuracy and reliability; more importantly, existing methods cannot effectively sense early internal defects of the insulator, and only when the defect develops to a certain extent and produces obvious heating or discharge on the surface can it be detected, often missing the best maintenance opportunity.

[0004] In terms of online monitoring, existing attempts are mostly focused on installing sensors on the insulator. However, these solutions face a difficult technical bottleneck: how to provide long-term, stable, and maintenance-free power supply for sensors installed on the high-voltage side. Battery-powered sensors need to be replaced frequently, photovoltaic-powered sensors are affected by weather and difficult to install on the surface of the insulator, and wire-powered sensors will severely damage the electric field distribution and insulation performance of the insulator.

[0005] Therefore, there is a lack of a composite insulator in the prior art that can sense internal defects in real time and accurately, and has self-powered capability, which has become a key technical bottleneck restricting the development of intelligent operation and maintenance and condition-based maintenance of power grids. SUMMARY

[0006] In order to solve the problems of existing composite insulators that internal defects are difficult to detect in time, high-voltage side sensor units cannot provide long-term and stable power supply, and long-term operation reliability is insufficient, the purpose of the present application is to provide a power transmission line defect sensing type composite insulator.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a power transmission line defect sensing type composite insulator, comprising an insulator body, a first fitting and a second fitting are respectively arranged at the upper and lower ends of the insulator body, a sheath and a shed are sequentially arranged outside the core rod of the insulator body, and a state sensing system and a wireless energy transmission system are integrated on the insulator body.

[0008] The state sensing system is used to monitor and analyze the electric field, vibration and ultrasonic signals on the surface of the insulator in real time to identify and locate internal defects.

[0009] The wireless power transmission system is distributed at intervals along the axial direction of the insulator body, and is used to transmit electrical energy non-contactly between the high-voltage end and the low-voltage end through magnetic resonance coupling, and to provide a continuous power supply for the state sensing system.

[0010] Preferably, the state-aware system includes:

[0011] An electroluminescent material layer coated on the outer surface of the umbrella skirt;

[0012] The photoelectric sensor embedded in the sheath has its photosensitive surface optically coupled to the electroluminescent material layer through an optical fiber embedded in the umbrella skirt;

[0013] A photoelectric sensor is built into a protective sleeve, and an optical fiber connected to the electroluminescent material layer is also embedded in the umbrella skirt. The photoelectric sensor collects the light signal emitted by the electroluminescent material layer through the optical fiber.

[0014] An ultrasonic sensor and a vibration acceleration sensor embedded in the sheath are used to synchronously acquire the ultrasonic echo signal and vibration signal of the insulator.

[0015] Preferably, the state perception system further includes a signal processing unit configured to perform fusion analysis on the signals collected by the photoelectric sensor, ultrasonic sensor, and vibration acceleration sensor, specifically executing the following steps:

[0016] The ultrasonic echo signal is sequentially subjected to adaptive noise complete set empirical mode decomposition for denoising and variational mode decomposition to generate ultrasonic feature vectors.

[0017] Frequency domain transformation is performed on mechanical vibration signals to extract fundamental frequency and harmonic features, generating vibration feature vectors;

[0018] The ultrasonic feature vector and the vibration feature vector are dynamically weighted and concatenated, and then input into the multilayer perceptron classification model for defect identification and classification.

[0019] Preferably, the wireless power transfer system includes:

[0020] Multiple coil plates are embedded in the sheath material at intervals along the axial direction of the insulator body. Each coil plate encapsulates a coil body. The multiple coil bodies together form a distributed magnetic resonance coupling path.

[0021] The power extraction connection unit, installed on the first fitting at the high-voltage end, is used to receive the transmitted energy, process, store and manage it, and supply power to the load. The two plates of the power extraction connection unit are respectively connected to the first fitting and the high-voltage wire, and are used to obtain electrical energy from the high-voltage wire side and convert it into high-frequency AC energy suitable for wireless transmission.

[0022] In addition, an electrical connection unit is provided on the second fitting at the low-voltage end, the electrical connection unit including an energy storage device.

[0023] Preferably, the sheath and the skirt are made of grafted modified alicyclic epoxy composite material by integral injection molding process; the first and second fittings are assembled with the ends of the mandrel by coaxial multi-directional pressing process, and the ends are sealed by high temperature vulcanized silicone rubber injection process.

[0024] Preferably, the first fitting is used to connect the high-voltage end of the conductor; the second fitting is used to connect the low-voltage end of the tower.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0026] 1. This invention converts changes in electric field into light signals using electroluminescent materials. Combined with multi-source sensing and analysis, it enables early detection and precise location of internal defects in insulators, solving the problems of detection lag and susceptibility to interference in traditional methods.

[0027] 2. This invention employs distributed magnetic resonance wireless power transmission technology to achieve non-contact energy transmission from the high-voltage side to the low-voltage side, completely solving the industry problem of long-term stable power supply for the high-voltage end sensing unit. Attached Figure Description

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0029] Fig. 1 This is a schematic diagram of the overall structure of the present invention;

[0030] Fig. 2 This is a partial cross-sectional structural schematic diagram of the present invention;

[0031] Fig. 3 This is a top-view cross-sectional structural diagram of the coil body of the present invention.

[0032] In the diagram: 10, sheath; 20, umbrella skirt; 30, core rod; 2, first fitting; 3, second fitting; 4, state sensing system; 41, electroluminescent material layer; 42, photoelectric sensor; 43, ultrasonic sensor; 44, vibration acceleration sensor; 45, signal processing unit; 46, optical fiber; 5, wireless power transmission system; 51, coil board; 52, coil body; 53, power supply connection unit; 54, power connection unit; 55, energy storage device. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0034] Please see Figs. 1 to 3 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0035] This invention provides a technical solution: a defect-sensing composite insulator for transmission lines. By integrating a multi-dimensional state sensing system 4 and a distributed wireless power transmission system 5 onto the insulator body, and optimizing the body material and assembly process, it solves the technical problems of traditional composite insulators, such as difficulty in detecting defects, unstable power supply to monitoring equipment, and insufficient structural reliability. This enables real-time identification, location, and autonomous continuous operation of the insulator's operating status. The insulator body consists of a core rod 30, a sheath 10, skirts 20, a first fitting 2, and a second fitting 3. These components work together to form a complete integrated structure for load-bearing, insulation, and function.

[0036] Overall structure:

[0037] The insulator body has a core rod 30 as the core load-bearing component, a sheath 10 tightly covering the outside of the core rod 30, and sheds 20 distributed at intervals along the axial direction of the sheath 10. The three form a layered insulation protection structure to ensure creepage distance and insulation performance.

[0038] The first fitting 2 is fixed to the high-voltage end and connected to the conductor, and the second fitting 3 is fixed to the low-voltage end and connected to the tower, forming an integrated load-bearing link of "first fitting 2, core rod 30, and second fitting 3", which also provides an installation foundation for the status sensing system 4 and the wireless power transmission system 5.

[0039] Material modification:

[0040] The sheath 10 and the umbrella skirt 20 are made of grafted modified alicyclic epoxy composite material, which improves the dielectric properties and weather resistance of the material.

[0041] The first fitting 2 and the second fitting 3 are made of ZAlSi12 cast aluminum alloy and are anodized to enhance corrosion resistance; the mandrel 30 is made of glass fiber reinforced epoxy resin pull rod to ensure mechanical strength and insulation performance.

[0042] Molding and Assembly:

[0043] The sheath 10 and the umbrella skirt 20 are made by integral injection molding. The mold positioning is used to achieve integrated molding, avoiding interface defects caused by segmented molding.

[0044] The first fitting 2, the second fitting 3, and the mandrel 30 are assembled using a coaxial multi-directional pressing process to ensure connection strength and coaxiality; the end seals are made using a high-temperature vulcanized silicone rubber injection process to form a sealing and protective layer to prevent water vapor penetration and flashover risks.

[0045] Sensing components:

[0046] Electric field sensing module: The outer surface of the umbrella skirt 20 is coated with an electroluminescent material layer 41, whose luminescence intensity is linearly responsive to the surface electric field intensity. The light signal is transmitted to the photoelectric sensor 42 in the sheath 10 through the optical fiber 46 embedded in the umbrella skirt 20, thereby realizing the indirect acquisition of electric field signals.

[0047] Mechanical defect sensing module: An ultrasonic sensor 43 and a vibration acceleration sensor 44 are embedded in the inner space of the sheath 10. The ultrasonic sensor 43 collects the ultrasonic echo signal inside the insulator, and the vibration acceleration sensor 44 collects the mechanical vibration signal, thus simultaneously acquiring information on the internal structure and external stress state.

[0048] Signal processing unit: The signal processing unit 45 uses an STM32H7 series microcontroller, which integrates a high sampling rate ADC module and a built-in edge computing unit to realize local processing and analysis of signals from photoelectric sensor 42, ultrasonic sensor 43 and vibration acceleration sensor 44.

[0049] Multi-signal fusion recognition:

[0050] Ultrasonic signal processing: The ultrasonic echo signal acquired by the ultrasonic sensor 43 is sequentially subjected to adaptive noise complete set empirical mode decomposition for noise reduction and variational mode decomposition to extract feature parameters and generate ultrasonic feature vectors.

[0051] Vibration signal processing: The mechanical vibration signal collected by the vibration acceleration sensor 44 is processed by frequency domain transformation to extract the fundamental frequency and harmonic features and generate a vibration feature vector.

[0052] Feature fusion and classification: The signal processing unit 45 uses a dynamic weight allocation strategy to splice two types of feature vectors and inputs them into the multilayer perceptron classification model to realize the identification and classification of four types of defects, including mandrel cracking, sheath damage, internal air gap, and interface debonding, as well as normal state.

[0053] Wireless power transfer system:

[0054] Distributed power transfer structure:

[0055] Coupling path: Coil plates 51 embedded in the sheath 10 are arranged at intervals along the insulator axis. Each coil plate 51 encapsulates the coil body 52, forming a distributed magnetic resonance coupling path to improve the energy transmission distance and stability.

[0056] Power extraction unit: A power extraction connection unit 53 is set on the first hardware 2 at the high voltage end. The first hardware 2 is connected to the high voltage wire through two brass plates. The power is obtained by capacitor voltage division and converted into 100kHz-200kHz high frequency AC energy by a high frequency inverter circuit.

[0057] Power connection and energy storage unit: A power connection unit 54 is provided on the second hardware 3 at the low voltage end, which includes a rectifier and filter module, a voltage regulator module and an energy storage device 55 to realize the conversion, voltage regulation and storage of high frequency energy.

[0058] Energy transfer and management mechanisms:

[0059] Energy transmission: Through the distributed magnetic resonance coupling method formed by the coil body 52, non-contact power transmission between the high-voltage end power take-off connection unit 53 and the low-voltage end power receiving connection unit 54 is realized, with a transmission efficiency of not less than 50%.

[0060] Power supply guarantee: The power connection unit 54 outputs a stable voltage of 3.3V-5V, which directly powers the status sensing system 4 on the one hand, and stores excess energy in the energy storage device 55 to ensure continuous power supply under extreme conditions.

[0061] System collaboration:

[0062] Power supply coordination: The wireless power transmission system 5 provides power to the status sensing system 4 in real time, and the power storage device 55 works in parallel with the real-time power supply to ensure the uninterrupted operation of the status sensing system 4 24 hours a day.

[0063] Data collaboration: The electric field, ultrasonic and vibration signals collected by the state perception system 4 are fused and analyzed by the signal processing unit 45 and then uploaded to the background system through the wireless communication module, while key defect data is stored locally.

[0064] Structural coordination: All sensing components of the state sensing system 4 and the coil plate 51 of the wireless power transmission system 5 are embedded inside the sheath 10 or the shed 20, without changing the external structure and insulation performance of the insulator, ensuring operational safety and compatibility.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A defect-sensing composite insulator for transmission lines, comprising an insulator body, characterized in that: The insulator body is provided with a first fitting (2) and a second fitting (3) at its upper and lower ends respectively. The core rod (30) of the insulator body is provided with a sheath (10) and a skirt (20) in sequence. The insulator body is integrated with a state sensing system (4) and a wireless power transmission system (5). The state sensing system (4) is used to monitor and analyze the electric field, vibration and ultrasonic signals on the surface of the insulator in real time to identify and locate internal defects; The wireless power transmission system (5) is distributed at intervals along the axial direction of the insulator body, and is used to transmit electrical energy non-contactly between the high-voltage end and the low-voltage end through magnetic resonance coupling, and to provide continuous power supply for the state sensing system (4).

2. The defect-sensing composite insulator for transmission lines according to claim 1, characterized in that: The state-aware system (4) includes: Electroluminescent material layer (41) coated on the outer surface of the umbrella skirt (20); The photoelectric sensor (42) embedded in the sheath (10) has its photosensitive surface optically coupled to the electroluminescent material layer (41) through the optical fiber (46) embedded in the umbrella skirt (20); A photoelectric sensor (42) is built into a protective sleeve (10). An optical fiber (46) connected to an electroluminescent material layer (41) is also embedded in the umbrella skirt (20). The photoelectric sensor (42) collects the light signal emitted by the electroluminescent material layer (41) through the optical fiber (46). An ultrasonic sensor (43) and a vibration acceleration sensor (44) embedded in the sheath (10) are used to synchronously collect ultrasonic echo signals and vibration signals of the insulator.

3. A defect-sensing composite insulator for transmission lines according to claim 2, characterized in that: The state perception system (4) further includes a signal processing unit (45), which is configured to perform fusion analysis on the signals collected by the photoelectric sensor (42), the ultrasonic sensor (43) and the vibration acceleration sensor (44), specifically performing the following steps: The ultrasonic echo signal is sequentially subjected to adaptive noise complete set empirical mode decomposition for denoising and variational mode decomposition to generate ultrasonic feature vectors. Frequency domain transformation is performed on mechanical vibration signals to extract fundamental frequency and harmonic features, generating vibration feature vectors; The ultrasonic feature vector and the vibration feature vector are dynamically weighted and concatenated, and then input into the multilayer perceptron classification model for defect identification and classification.

4. A defect-sensing composite insulator for transmission lines according to claim 1, characterized in that: The wireless power transfer system (5) includes: Multiple coil plates (51) are embedded in the sheath (10) material at intervals along the axial direction of the insulator body. Each coil plate (51) encapsulates a coil body (52). The multiple coil bodies (52) together form a distributed magnetic resonance coupling path. The power collection connection unit (53) set on the first fitting (2) at the high voltage end is used to receive the transmitted energy, process, store and manage it, and supply power to the load; the two plates of the power collection connection unit (53) are respectively connected to the first fitting (2) and the high voltage wire, and are used to obtain electrical energy from the high voltage wire side and convert it into high frequency AC energy suitable for wireless transmission. In addition, an electrical connection unit (54) is provided on the second fitting (3) at the low voltage end, the electrical connection unit (54) including an energy storage device (55).

5. A defect-sensing composite insulator for transmission lines according to claim 1, characterized in that: The sheath (10) and the umbrella skirt (20) are made of grafted modified alicyclic epoxy composite material by integral injection molding process; the first fitting (2) and the second fitting (3) are assembled with the ends of the mandrel (30) by coaxial multi-directional pressing process and the ends are sealed by high temperature vulcanized silicone rubber injection process.

6. A defect-sensing composite insulator for transmission lines according to claim 1, characterized in that: The first fitting (2) is used to connect the high-voltage end of the conductor; the second fitting (3) is used to connect the low-voltage end of the tower.

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