Power transmission overhead line insulator defect detection device and method

Abstract

The invention discloses a power transmission overhead line insulator defect detection device and method, and belongs to the technical field of insulator detection. The device comprises a sensor module, a signal conditioning module, a data acquisition and analysis module and a positioning module, wherein the sensor modules are deployed at two ends of a power transmission overhead line and are used for receiving fault magnetic field signals generated by insulator flashover in a non-contact manner and converting the fault magnetic field signals into initial electric signals; the signal conditioning module filters and amplifies the initial electric signal; the data acquisition and analysis module acquires the processed fault electric signal, and calculates the fault position through a time difference method based on the time difference of the signal reaching the sensors at the two ends; and the positioning module completes fault positioning. The fault magnetic field signal generated by insulator flashover is received in a non-contact manner, so that non-contact online monitoring is realized, weak fault signal detection sensitivity and defect positioning precision are improved, and early warning and accurate positioning of insulator flashover faults can be effectively realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulator detection, and in particular to a device and method for detecting defects of insulators of a power transmission overhead line. BACKGROUND

[0002] As the core channel of power transmission, the operation stability of the power transmission overhead line directly determines the power supply reliability and safety level of the power system. As a key support and insulation component in the line, the insulator is exposed to complex environments such as industrial pollution, salt mist corrosion, rain, snow and rime for a long time, and is prone to defects such as surface contamination accumulation and internal crack development, which may cause abnormal increase of leakage current and eventually lead to flashover failure. According to statistics, the proportion of power transmission line trip accidents caused by insulator failure has exceeded 15%. Such failures not only cause large-scale unplanned power outages, but also may cause chain accidents such as wire breakage, resulting in huge economic losses and safety risks. The occurrence of insulator flashover has dynamic characteristics, including intermittent arcing in the early stage of failure and current mutation in the flashover instant, which together constitute the complete process of defect development. The current change rate in the flashover instant is much higher than that in the conventional external discharge, and the electric and magnetic signals generated thereby contain core information such as defect position and severity. Therefore, accurate capture and analysis of these characteristic signals are the key technical path to realize early warning, accurate positioning and effective prevention and control of flashover failure.

[0003] Current detection technologies for defects of insulators of power transmission overhead lines still generally focus on the collection and analysis of fault electric signals (such as leakage current and traveling wave voltage), but have long neglected the diagnostic value of the magnetic field signals generated synchronously in the flashover process, forming a technical limitation of "single-dimensional perception". Among the existing electric signal detection means, the high-frequency current transformer (HFCT) is a widely used sensing device, but this technology has obvious shortcomings. On the one hand, its sensitivity is low and it is difficult to capture early weak fault signals, and it needs to be installed at a specific position of the conductor in a power-off state, which cannot meet the online monitoring needs of the running line, seriously limiting the timeliness of fault warning. On the other hand, it is not a completely non-contact sensing device, and the installation and maintenance process is complicated, and the detection results are easily affected by the line structure, signal attenuation and strong electromagnetic interference, resulting in obvious errors in defect positioning.

[0004] In summary, the existing insulator defect detection technologies mainly have the following shortcomings: first, the sensing method relies on power-off installation, which cannot meet the online monitoring needs of the running line; second, the signal detection dimension is single, and the magnetic field information is not integrated, resulting in insufficient early fault recognition capability; third, the positioning accuracy is greatly affected by signal attenuation and electromagnetic interference, making it difficult to achieve accurate positioning of the fault point. SUMMARY

[0005] The purpose of the present application is to provide a power transmission overhead line insulator defect detection device and method to overcome the problem of the sensing mode relying on power-off installation, single signal detection dimension and insufficient positioning accuracy.

[0006] The present application solves the above technical problems by the following technical solutions: The present application provides a power transmission overhead line insulator defect detection device, comprising: A sensor module is arranged at both ends of the power transmission overhead line for non-contact reception of the fault magnetic field signal generated by the flashover of the insulator and conversion of the signal into an initial electric signal; A signal conditioning module is electrically connected to the sensor module for filtering and amplifying the initial electric signal and outputting a fault electric signal; A data acquisition and analysis module is electrically connected to the signal conditioning module for collecting the fault electric signal and calculating the position of the insulator where the flashover fault occurs by using the time difference method based on the time difference of the fault electric signal reaching the sensor module; A positioning module is used to locate the position of the insulator where the flashover fault occurs.

[0007] The present application further improves by further comprising a communication module for sending the fault electric signal and the position of the insulator where the flashover fault occurs to the cloud.

[0008] The present application further improves by the communication module adopting a dual-mode redundant communication supporting 4G mobile network and WiFi wireless network.

[0009] The present application further improves by the sensor module adopting a non-contact inverse magnetic electromagnetic field sensor; The non-contact inverse magnetic electromagnetic field sensor comprises: A cantilever; A piezoelectric driving unit is arranged on the cantilever for driving the cantilever to vibrate at its mechanical resonance frequency; A magnetostrictive sensitive layer is covered on the surface of the cantilever for deformation with the vibration of the cantilever; A pickup coil is arranged around the periphery of the cantilever structure for sensing the magnetic flux change of the magnetostrictive sensitive layer and outputting an initial electric signal.

[0010] The present application further improves by the signal conditioning module comprising a filter circuit and an amplifier circuit connected in sequence.

[0011] The present application further improves by the filter circuit being a Butterworth low-pass filter circuit with adjustable cutoff frequency and the amplifier circuit being an instrument amplifier circuit with adjustable gain.

[0012] The present application further improves by the positioning module adopting Beidou satellite positioning.

[0013] The application also provides a method for detecting defects of insulators of a power transmission overhead line, comprising the following steps: S1, receiving a magnetic field signal by a magnetic field sensor arranged at both ends of the power transmission overhead line, and converting the magnetic field signal into an initial electric signal, wherein the magnetic field signal is formed by a fault magnetic field signal generated when the insulator flashes over and propagates along the power transmission overhead line; S2, filtering and amplifying the initial electric signal to obtain a fault electric signal; S3, obtaining a first time and a second time when the fault electric signal reaches the magnetic field sensors at both ends of the power transmission overhead line, and calculating and locating the position of the insulator that flashes over by using a time difference method based on the first time, the second time and the length of the power transmission overhead line.

[0014] The application further improves that the time difference method is specifically:

[0015] wherein, is the position of the insulator that flashes over to the first end of the power transmission overhead line; is the speed of light; is the length of the power transmission overhead line; is the first time; is the second time.

[0016] The application further improves that when the sensor module adopts a non-contact inverse magnetic electromagnetic field sensor, step S1 specifically comprises the following steps: continuously oscillating a cantilever of the non-contact inverse magnetic electromagnetic field sensor at its mechanical resonance frequency by piezoelectric driving; a magnetostrictive layer arranged on the cantilever deforms with the oscillation, and based on the inverse magnetostrictive effect, external fault magnetic field information to be measured is modulated into periodic changes of the magnetization intensity of the magnetostrictive layer; the changes of the magnetization intensity are converted into the initial electric signal by a pickup coil surrounding the cantilever based on the principle of electromagnetic induction.

[0017] Compared with the prior art, the application has the following positive progress effects: The power transmission overhead line insulator defect detection device provided by the application comprises a sensor module, a signal conditioning module, a data acquisition and analysis module and a positioning module; the sensor module is arranged at both ends of the power transmission overhead line and is used for non-contact receiving of a fault magnetic field signal generated by insulator flashover and conversion into an initial electric signal; the signal conditioning module performs filtering and amplification processing on the initial electric signal; the data acquisition and analysis module collects the processed fault electric signal, and calculates a fault position through a time difference method based on a time difference of the signal arriving at the sensors at both ends; and the positioning module completes fault positioning. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application, and do not limit the application in any way.

[0019] Figure 1 A method flowchart of the power transmission overhead line insulator defect detection device of the application; Figure 2 A structural schematic diagram of the power transmission overhead line insulator defect detection device of the application; Figure 3 A structural schematic diagram of the non-contact inverse magnetic electromagnetic field sensor of the application; Figure 4 A positioning principle schematic diagram of the time difference method of the application; Figure 5 An application schematic diagram of the power transmission overhead line insulator defect detection device of the application. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described below in conjunction with the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, rather than all the embodiments of the application. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0021] The following detailed description of embodiments of the application in the drawings provided is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the application.

[0022] It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of embodiments of the application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the application is used, it is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", etc. are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0024] In addition, it should be noted that unless otherwise explicitly specified and limited, if the terms "set", "mount", "connected", "connected" appear, they should be broadly understood, for example, they can be fixedly connected, or they can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0025] The application will be further described in detail below in combination with the drawings and specific embodiments, which are an explanation of the application rather than a limitation.

[0026] The application provides a kind of transmission overhead line insulator defect detection device, comprising: Sensor module is arranged at the two ends of transmission overhead line, for non-contact receiving fault magnetic field signal generated by insulator flashover, and it is converted into initial electric signal; Signal conditioning module is electrically connected with sensor module, for filtering and amplifying initial electric signal, and outputting fault electric signal; Data acquisition and analysis module is electrically connected with signal conditioning module, for collecting fault electric signal, and based on the time difference of fault electric signal reaching sensor module, the position of insulator that occurs flashover fault is calculated using time difference method; Positioning module is used to locate the position of insulator that occurs flashover fault.

[0027] The non-contact inverse magnetic electromagnetic field sensor adopted by the application constructs an efficient magnetic signal sensing mechanism through the cooperative design of piezoelectric driving and magnetostrictive modulation, accurately modulates external fault magnetic field information into magnetization intensity change, and then completes signal conversion through electromagnetic induction of a pickup coil; in principle, it breaks through the bottleneck of low sensitivity of traditional HFCT, can effectively capture weak magnetic field signals in the early stage of insulator flashover, and solves the problem of "perception blind area" of early defects for traditional devices; at the same time, through the signal processing process of low noise amplification and phase locked amplification, environmental electromagnetic interference can be further filtered out, and even in complex working conditions, effective signals with high signal-to-noise ratio can be extracted, providing a reliable sensing basis for early defect diagnosis.

[0028] The non-contact sensing architecture is combined with the time difference method positioning, which greatly improves the fault diagnosis efficiency and accuracy. Compared with the contact detection mode of traditional HFCT which needs to be installed under power-off, the non-contact sensor of the application does not need to be in direct contact with the power transmission conductor, and can be deployed and monitored under normal operation of the line, completely avoiding the influence of power-off operation on power supply reliability, and simplifying the installation and maintenance process, and expanding the detection coverage. In the positioning link, relying on the accurate distance data provided by the Beidou satellite positioning module, combined with the time difference of the arrival of the fault magnetic field traveling wave at the sensors at both ends of the line, the position is solved by using the electromagnetic wave light speed propagation characteristics, realizing the rapid positioning of the fault position; in addition, the efficient data transmission capability of the 4G and WiFi dual-mode communication module can upload the positioning results and fault data to the cloud in real time, providing accurate guidance for the rapid repair operation of the operation and maintenance personnel, significantly shortening the fault processing cycle and reducing the power loss.

[0029] In a specific embodiment of the application, the data acquisition and analysis module adopts a combination scheme of STM32H743VI microcontroller + ADS1256 analog-to-digital conversion chip, which has high-performance data processing and high-precision acquisition capability; ADS1256 has 24-bit resolution, and the sampling rate can be adjusted between 2.5SPS-30kSPS (the typical setting for fault signal acquisition is 10kSPS); the input range is ±5V, which matches the output of the conditioning module; the integral non-linear error (INL) is ≤±0.001%, which ensures the acquisition accuracy; the built-in PGA (programmable gain amplifier) and anti-aliasing filter further improve the signal acquisition quality.

[0030] STM32H743VI is based on ARM Cortex-M7 core, with a clock speed of up to 400MHz, and has powerful floating point operation capability, which can quickly run time difference positioning algorithm; built-in 1MB SRAM and 2MB Flash, supporting local storage of more than 100,000 fault data; equipped with SPI, UART, DMA and other rich peripherals, realizing high-speed data interaction with ADC chip, storage module and communication module; external 16GB eMMC storage chip is used for long-term storage of fault raw data and positioning results.

[0031] The ADS1256 converts the analog fault electrical signal after conditioning into a digital signal, which is transmitted to the STM32H743VI through the SPI interface; the microcontroller caches and stores the digital signal, and runs the time difference positioning algorithm based on the improved generalized cross-correlation to calculate the preliminary position information of the fault point; at the same time, it has data verification and abnormality judgment function to ensure data validity.

[0032] In a specific embodiment of the present application, the positioning module selects UBLOX NEO-8M Beidou / GPS dual-mode positioning module, which preferentially adopts Beidou positioning system to ensure localization and positioning accuracy, and is used for positioning the position of flashover fault to provide accurate distance data for time difference positioning.

[0033] Preferably, it further comprises a communication module for transmitting the fault electrical signal and the position of the insulator with flashover fault to the cloud.

[0034] By adding a communication module, the problem of remote access of the output information of the detection device is solved, and cloud transmission and real-time monitoring of data are realized. Specifically, the communication module is used as an independent component to transmit the fault electrical signal and the position information of the insulator to the cloud; wherein the fault electrical signal is reliable data processed by the signal conditioning module, and the position of the insulator is the accurate result calculated by the data acquisition and analysis module based on the time difference method, which is transmitted to the cloud through the communication module, so that the remote monitoring center can receive and analyze these information in time, thereby improving the fault response speed and system management efficiency.

[0035] Preferably, the communication module adopts a dual-mode redundant communication supporting 4G mobile network and WiFi wireless network.

[0036] In a specific embodiment of the present application, a SIM7600CE 4G module + ESP8266EX WiFi module dual-mode redundant design is adopted to ensure the reliability and flexibility of data transmission.

[0037] By making the communication module adopt a dual-mode redundant communication supporting 4G mobile network and WiFi wireless network, the problem of unreliable single communication mode is solved. Specifically, the dual-mode design combines the wide coverage of 4G mobile network and the high speed stability of WiFi wireless network, and the redundancy mechanism ensures automatic switching to another network when one network fails, thereby improving the continuity and anti-interference ability of data transmission. As the core transmission component, the communication module, through such redundant configuration, ensures the stable sending of fault electrical signals and location information to the cloud in various environments, avoids delays or losses due to network problems, and strengthens the online monitoring efficiency of the overall device.

[0038] Preferably, the sensor module adopts a non-contact inverse magnetic electromagnetic field sensor. The non-contact inverse magnetic electromagnetic field sensor comprises: a cantilever; a piezoelectric driving unit arranged on the cantilever for driving the cantilever to vibrate at its mechanical resonance frequency; a magnetostrictive sensitive layer covering the surface of the cantilever for deforming with the vibration of the cantilever; a pickup coil arranged around the periphery of the cantilever structure for sensing the magnetic flux change of the magnetostrictive sensitive layer and outputting an initial electrical signal.

[0039] Through the specific design of the non-contact inverse magnetic electromagnetic field sensor, the problems of insufficient sensitivity and anti-interference of the sensor module in the detection process are effectively solved, and non-contact acquisition of high-precision magnetic field signals is realized. Among them, the sensor module adopts a non-contact inverse magnetic electromagnetic field sensor, which avoids the need for physical contact installation, supports online monitoring and reduces maintenance complexity; the non-contact inverse magnetic electromagnetic field sensor comprises a cantilever as a mechanical vibration basic structure, which facilitates efficient energy transfer; the piezoelectric driving unit is arranged on the cantilever and drives the cantilever to vibrate at its mechanical resonance frequency, which utilizes the resonance amplification effect to enhance the response ability to weak fault magnetic field signals; the magnetostrictive sensitive layer covers the surface of the cantilever and deforms with the vibration, which modulates external magnetic field information into vibration based on the inverse magnetostrictive effect, effectively isolating environmental electromagnetic interference; the pickup coil surrounds the periphery of the cantilever structure and senses the magnetic flux change of the magnetostrictive sensitive layer to output an initial electrical signal, which ensures the stability and reliability of signal conversion through electromagnetic induction principle.

[0040] Preferably, the signal conditioning module comprises a filter circuit and an amplification circuit connected in sequence.

[0041] By specifically limiting the structure of the signal conditioning module, the signal processing process is optimized to solve the problem of signal interference and attenuation. The signal conditioning module includes a filter circuit and an amplifier circuit connected in sequence, wherein the filter circuit is used to remove noise and interference components in the initial electric signal and improve signal purity; the amplifier circuit is used to enhance the amplitude of the signal to a level suitable for subsequent processing. By connecting in sequence, filtering is performed first and then amplification is performed, avoiding the enhancement of noise during amplification, thereby ensuring that the output fault electric signal has a high signal-to-noise ratio, which helps to improve the accuracy and reliability of insulator position calculation.

[0042] Preferably, the filter circuit is a Butterworth low-pass filter circuit with adjustable cutoff frequency, and the amplifier circuit is an instrument amplifier circuit with adjustable gain.

[0043] By introducing filter and amplifier circuits with adjustable parameters, the flexibility and adaptability of signal conditioning are enhanced to solve the problem of unstable signal quality caused by fixed parameters. Specifically, the filter circuit uses a Butterworth low-pass filter circuit with adjustable cutoff frequency. The Butterworth filter provides a flat passband response, reducing amplitude distortion of the signal during filtering. At the same time, the adjustable cutoff frequency allows dynamic adjustment of the filtering range according to the frequency characteristics of the fault signal and environmental interference, effectively filtering out high-frequency noise and electromagnetic interference, preserving the key low-frequency information of insulator flashover faults, and ensuring the purity of the fault electric signal. The amplifier circuit uses an instrument amplifier circuit with adjustable gain. The instrument amplifier has high input impedance and excellent common-mode rejection ratio, which can effectively suppress common-mode noise and external electromagnetic interference in the line. The adjustable gain allows the system to adaptively adjust the amplification factor according to the strength of the input signal, avoiding signal overload leading to saturation or signal weakness leading to information loss, thereby outputting a stable fault electric signal with appropriate amplitude, providing reliable input for the subsequent data acquisition and analysis module, and improving the accuracy and reliability of insulator fault positioning.

[0044] In a specific embodiment of the present application, a 4th-order Butterworth low-pass filter circuit is constructed using an LMV841 operational amplifier, which is optimized for the characteristics of transmission line fault signals. The cutoff frequency can be adjusted by external resistance and capacitance (typically set to 100 kHz, matching the main frequency range of the fault signal); the passband ripple is ≤0.1 dB, the stopband attenuation is ≥60 dB / octave, effectively filtering out high-frequency noise and electromagnetic interference; the input offset voltage is ≤2 mV, and the input bias current is ≤10 nA, ensuring the purity of weak signals. The core chip of the amplifier circuit is INA128 instrumentation amplifier, which has high common-mode rejection ratio and low noise characteristics, suitable for amplifying weak signals. The gain range is 1-1000 times adjustable (according to the output signal amplitude of the sensor, typically set the gain to 100 times, amplify the 10 mV level signal to 1 V level).

[0045] Preferably, the positioning module adopts Beidou satellite positioning.

[0046] By adopting the Beidou satellite positioning technology, the global coverage, high precision and strong anti-interference characteristics are utilized to ensure that the position of the insulator where the flashover fault occurs can be stably and accurately determined in the complex electromagnetic environment of the overhead transmission line, and more reliable fault point identification is realized.

[0047] Based on the same inventive concept, the application further provides a method for detecting insulator defects of an overhead transmission line, comprising the following steps: S1, receiving a magnetic field signal by a magnetic field sensor arranged at both ends of the overhead transmission line, and converting the magnetic field signal into an initial electric signal, wherein the magnetic field signal is formed by a fault magnetic field signal generated when the insulator flashes over and propagates along the overhead transmission line; S2, filtering and amplifying the initial electric signal to obtain a fault electric signal; S3, obtaining a first time and a second time when the fault electric signal reaches the magnetic field sensors at both ends of the overhead transmission line, and calculating and positioning the position of the insulator where the flashover fault occurs by using a time difference method based on the first time, the second time and the length of the overhead transmission line.

[0048] The detection method provided by the application can ensure accurate identification of insulator flashover faults by integrating signal receiving, processing and positioning steps. Specifically, in step S1, the magnetic field signal is received by the magnetic field sensor arranged at both ends of the overhead transmission line and converted into an initial electric signal. This method uses a non-contact sensor to capture the fault magnetic field signal propagating along the line, avoiding the limitations of traditional power-off installation and providing a reliable signal source for subsequent positioning. In step S2, the initial electric signal is filtered and amplified to obtain a fault electric signal. This processing removes noise interference and enhances signal strength, improves signal quality and reduces the influence of electromagnetic interference on positioning. In step S3, the time difference of the fault electric signal reaching both ends is obtained and the position is calculated by using a time difference method. This step directly calculates the fault point based on time information, overcomes the error caused by signal attenuation and realizes high-precision positioning.

[0049] Preferably, the time difference method is specifically:

[0050] wherein, is the position of the insulator where the flashover fault occurs to the first end of the overhead transmission line; is the speed of light; is the length of the overhead transmission line; is the first time; is the second time.

[0051] Preferably, when the sensor module adopts a non-contact inverse magnetic electromagnetic field sensor, step S1 specifically comprises the following steps: The cantilever of the non-contact inverse magnetic electromagnetic field sensor is continuously oscillated at its mechanical resonance frequency through piezoelectric driving; The magnetostrictive layer arranged on the cantilever is deformed with the oscillation, and based on the inverse magnetostrictive effect, the external fault magnetic field information is modulated into the periodic change of the magnetization intensity of the magnetostrictive layer; The change of the magnetization intensity is converted into an initial electric signal through a pickup coil surrounding the cantilever based on the electromagnetic induction principle.

[0052] The cantilever is continuously oscillated at its mechanical resonance frequency through piezoelectric driving, and the maximum amplitude effect in the resonance state is utilized to enhance the response capability to weak magnetic field changes, thereby ensuring that the sensor can be effectively excited in a complex environment; the magnetostrictive layer arranged on the cantilever is deformed with the oscillation, and based on the inverse magnetostrictive effect, the external fault magnetic field information is modulated into the periodic change of the magnetization intensity, thereby realizing efficient capture and modulation of the magnetic field signal and reducing the influence of external electromagnetic interference; the change of the magnetization intensity is converted into an initial electric signal through a pickup coil surrounding the cantilever based on the electromagnetic induction principle, thereby ensuring the reliability of non-contact detection and avoiding signal attenuation and installation and maintenance problems caused by direct contact.

[0053] In a specific embodiment of the present application, referring to Figure 2 A device for detecting defects of insulators of a power transmission overhead line, comprising: A sensor module: composed of a non-contact inverse magnetic electromagnetic field sensor, used for receiving a fault magnetic field signal from the power transmission overhead line and converting the fault magnetic field signal into an acquired electric signal output to a conditioning amplification module. A conditioning amplification module: composed of a filter circuit and an amplification circuit, used for conditioning and amplifying the acquired electric signal and outputting a fault electric signal to a data acquisition and analysis module.

[0054] A data acquisition and analysis module: used for analog-digital conversion and storage of the fault electric signal and implementation of a time difference positioning algorithm.

[0055] A communication module: used for transmitting the acquired fault electric signal and positioning data to the cloud, and the communication module adopts a combination of 4G and WiFi modules to send data to the cloud.

[0056] A positioning module: the positioning module adopts a Beidou satellite positioning module to acquire position information and is used for positioning the position of a fault flashover to provide accurate distance data for time difference positioning.

[0057] Referring to Figure 4When a flashover occurs in the middle of a transmission line, its magnetic field signal will propagate along the overhead line to both sides. The length of the overhead transmission line is... The time it takes to reach the beginning (i.e., the first time) is t1, and the time it takes to reach the end (i.e., the second time) is t2. Since the propagation speed of electromagnetic waves is the speed of light c, the fault source reaches the beginning at... The distance (i.e., the distance from the insulator where a flashover fault occurs to the beginning of the overhead transmission line) can be calculated using the formula: Calculated.

[0058] This device includes a sensor module, a conditioning and amplification module, a data acquisition and analysis module, a communication module, and a positioning module. The sensor module uses a non-contact inverse magneto-electromagnetic field sensor, which achieves high-sensitivity magnetic field detection through piezoelectric drive and magnetostrictive modulation. The communication module combines 4G and WiFi to transmit data, and the positioning module relies on BeiDou satellite positioning to provide accurate distance data.

[0059] By receiving fault magnetic field signals generated by insulator flashover in a non-contact manner, the limitations of existing single-dimensional electrical signal detection technology can be overcome, enabling non-contact online monitoring. This improves the sensitivity of weak fault signal detection and the accuracy of defect location, simplifies the installation and maintenance process, reduces operation and maintenance costs, and can effectively achieve early warning and accurate location of insulator flashover faults, providing reliable technical support for the prevention and control of insulator defects in power systems. Specifically, the sensor module is deployed at both ends of the overhead power transmission line. It receives the fault magnetic field signal generated by insulator flashover in a non-contact manner and converts it into an initial electrical signal, avoiding the need for power outage installation and realizing online monitoring. At the same time, it uses the magnetic field signal as a new dimension to supplement the shortcomings of single electrical signal detection. The signal conditioning module is electrically connected to the sensor module. It filters and amplifies the initial electrical signal to output the fault electrical signal. By removing noise and enhancing signal quality, it ensures the accuracy of subsequent analysis. The data acquisition and analysis module is electrically connected to the signal conditioning module. It collects the fault electrical signal and calculates the location of the insulator where the flashover fault occurred based on the time difference of its arrival at the sensor module. The time difference directly reflects the location information, reducing the impact of signal attenuation and interference. The positioning module is used to locate the location of the insulator where the flashover fault occurred, providing the final accurate result.

[0060] For the method of the above-mentioned detection device for insulator defects in overhead power transmission lines, please refer to [link to relevant documentation]. Figure 1 It includes the following stages: Flashover occurs: Insulators of overhead power transmission lines flashover due to a fault, generating a fault magnetic field signal from the location of the fault. Traveling wave propagation: After an insulator experiences a flashover fault and generates a fault magnetic field signal, the fault traveling wave will propagate along the overhead line to both ends. Sensor receiving: After the magnetic field traveling wave signal reaches the magnetic field sensor deployed at both ends of the overhead line, the magnetic field sensor collects the magnetic field signal; Magnetic field signal conversion: The collected magnetic field signal is converted into an electrical signal by the magnetic field signal conversion module built into the sensor; Filtering and amplification: The collected electrical signal is filtered, amplified, and modulated to obtain a fault electrical signal; Time difference method analysis: According to the time difference of the fault electrical signal and the line distance, the location of the fault flashover is calculated, positioned, and the data is transmitted to the cloud.

[0061] The fault magnetic field signal generated by the insulator flashover is received by the magnetic field sensor at both ends of the overhead line after traveling wave propagation. The magnetic field signal is then converted into an electrical signal and filtered and amplified. Finally, the time difference method is used to analyze and locate the fault position and transmit data to the cloud. This breakthrough overcomes the limitations of traditional detection techniques, such as single sensing dimension and insufficient sensitivity, enabling non-contact online monitoring and rapid and accurate fault positioning, providing technical support for intelligent operation and maintenance of transmission overhead lines.

[0062] Referring to Figure 3 , the non-contact inverse magnetic electromagnetic field sensor integrates a magnetic field sensor, a piezoelectric layer, a data acquisition and analysis module, a communication module, and a positioning module. The overall design uses a cantilever extension and a cylindrical shell. The cantilever extension is 15 cm long, the lower cylindrical shell is 10 cm in diameter and 8 cm in height, and all circuit structures are housed inside. The side opening provides voltage input to power the circuit board and the piezoelectric layer. A data transmission port is also provided at the bottom to ensure that stored electrical signals and positioning data can be obtained directly from the data acquisition and analysis module when the communication module fails to function.

[0063] The sensor achieves cantilever vibration through piezoelectric driving to provide a basis for magnetic signal modulation. The specific process is as follows: a specific voltage is applied to the piezoelectric layer of the sensor, which generates mechanical vibration through the inverse piezoelectric effect, thereby driving the cantilever of the sensor to continuously oscillate at a U-shaped mechanical resonance frequency of about 509.25 kHz, providing stable mechanical motion conditions for the subsequent magnetization intensity modulation of the magnetostrictive layer.

[0064] Magnetic field detection is also achieved through magnetostrictive modulation and induction output, which includes the following steps: A magnetostrictive multilayer film containing magnetic sensitive material is coated on the cantilever, and the multilayer film forms a magnetic flux closed structure. When the cantilever oscillates, the magnetostrictive layer deforms with the vibration, and the inverse magnetostrictive effect causes the magnetization intensity in the layer to change periodically. The external magnetic field to be measured will change the change rule of the magnetization intensity, modulating the measured magnetic field information into the magnetization intensity change. The cantilever peripheral loop surrounds the pickup coil, and the magnetization intensity change of magnetostrictive layer causes the synchronous change of magnetic flux through the coil, and the coil induces a weak electric signal according to the electromagnetic induction law; the electric signal is amplified by a low-noise amplifier, and the effective frequency components are extracted by a lock-in amplifier, and then converted into a readable electric signal, and the external magnetic field to be measured is inversely deduced by analyzing the characteristics of the electric signal.

[0065] Referring to Figure 5 When the fault flashover occurs in the overhead line, the fault magnetic field signal is detected by the non-contact magnetic field sensor installed at both ends, and the fault position can be located by the time difference positioning algorithm, and the data is sent to the cloud through the communication module built in the sensor.

[0066] Finally, it should be noted that: the above-mentioned embodiments, only as one or more specific forms of the present application exist, their purpose is to clarify the concept, principle and application mode of the present application through specific examples, and by no means intend to limit the scope of protection of the present application to these specific embodiments. In fact, the true value of the present application lies in its proposed technical ideas and innovations, not its forms or means of implementation.

[0067] For ordinary skilled persons in the art, after thoroughly reading and understanding the technical solutions of the present application, they have the ability to make various forms of changes, modifications or equivalent replacements to the specific embodiments of the invention based on their own professional knowledge and skills. These changes may include but are not limited to adjusting the value range of technical parameters, optimizing the algorithm process to improve efficiency, replacing part of the technical components to achieve better compatibility or reduce cost, etc. As long as the technical solutions after these changes still maintain the technical characteristics required by the original invention, that is, still can realize the core function and effect of the present application, these changes should be considered as falling within the scope of protection of the claims of the present application.

[0068] In addition, with the continuous progress and development of technology, new technical means and methods are emerging, which also provides a broad space for further improvement and perfection of the present application. Therefore, the protection scope of the present application should also include those reasonable foreseeable improvements and extensions based on the existing technology, as long as these improvements and extensions do not deviate from the basic principles and core ideas of the present application, they should be considered as the equivalents of the present application, and also be protected by the patent right.

Claims

1. A device for detecting defects in insulators of overhead power transmission lines, characterized in that, include: The sensor module is deployed at both ends of the overhead power transmission line to receive the fault magnetic field signal generated by the flashover of the insulator in a non-contact manner and convert it into an initial electrical signal. The signal conditioning module, electrically connected to the sensor module, is used to filter and amplify the initial electrical signal and output a fault electrical signal. The data acquisition and analysis module is electrically connected to the signal conditioning module. It is used to acquire fault electrical signals and calculate the location of the insulator where the flashover fault occurred based on the time difference between the arrival of the fault electrical signals at the sensor module and the time difference method. The positioning module is used to locate the position of the insulator where a flashover fault has occurred.

2. The detection device for defects in insulators of overhead power transmission lines according to claim 1, characterized in that, It also includes a communication module for transmitting fault signals and the location of insulators that have experienced flashover faults to the cloud.

3. The detection device for defects in insulators of overhead power transmission lines according to claim 2, characterized in that, The communication module adopts dual-mode redundant communication that supports both 4G mobile networks and WiFi wireless networks.

4. The detection device for defects in insulators of overhead power transmission lines according to claim 1, characterized in that, The sensor module uses a non-contact reverse magnetic electromagnetic field sensor. The non-contact reverse magnetic electromagnetic field sensor includes: cantilever; A piezoelectric drive unit, mounted on the cantilever, is used to drive the cantilever to vibrate at its mechanical resonant frequency. A magnetostrictive sensitive layer is applied to the surface of the cantilever to deform in response to cantilever vibration. A pickup coil is arranged around the periphery of the cantilever structure to sense changes in the magnetic flux of the magnetostrictive sensitive layer and output an initial electrical signal.

5. The detection device for defects in insulators of overhead power transmission lines according to claim 1, characterized in that, The signal conditioning module includes a filter circuit and an amplifier circuit connected in sequence.

6. The detection device for defects in insulators of overhead power transmission lines according to claim 5, characterized in that, The filtering circuit is a Butterworth low-pass filter circuit with adjustable cutoff frequency, and the amplification circuit is an instrumentation amplifier circuit with adjustable gain.

7. The detection device for defects in insulators of overhead power transmission lines according to claim 1, characterized in that, The positioning module uses BeiDou satellite positioning.

8. A method for detecting defects in insulators of overhead power transmission lines as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Magnetic field signals are received by magnetic field sensors deployed at both ends of the overhead transmission line and converted into initial electrical signals. The magnetic field signals are formed by the fault magnetic field signals generated when the insulator experiences a flashover fault and propagate along the overhead transmission line. S2. Filter and amplify the initial electrical signal to obtain the fault electrical signal; S3. Obtain the first and second times when the fault electrical signal arrives at the magnetic field sensors at both ends of the overhead transmission line. Based on the first and second times and the length of the overhead transmission line, calculate and locate the insulator position where the flashover fault occurred using the time difference method.

9. The method for detecting defects in insulators of overhead power transmission lines according to claim 8, characterized in that, The time difference method is as follows: in, The location from the insulator where a flashover fault occurred to the beginning of the overhead transmission line; The speed of light; This refers to the length of the overhead power transmission line; For the first time; This is the second time.

10. The method for detecting defects in insulators of overhead power transmission lines according to claim 8, characterized in that, When the sensor module uses a non-contact reverse magnetic electromagnetic field sensor, step S1 is specifically... Includes the following steps: The cantilever of the non-contact reverse magneto-electromagnetic field sensor oscillates continuously at its mechanical resonant frequency through piezoelectric drive. The magnetostrictive layer set on the cantilever deforms with oscillation. Based on the inverse magnetostrictive effect, the external fault magnetic field information to be measured is modulated into the periodic changes in the magnetization intensity of the magnetostrictive layer. By using a pickup coil that surrounds the cantilever, changes in magnetization intensity are converted into an initial electrical signal based on the principle of electromagnetic induction.

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