Device and method for detecting lead-lined damage to cable joints using electromagnetic wave penetration effect

Abstract

This invention relates to a device and method for detecting lead-lined damage to cable joints using the electromagnetic wave penetration effect. The detection device includes an electromagnetic wave signal generator built into the copper shell of the cable joint, a power extraction unit built into the copper shell of the cable joint, and an electromagnetic wave signal detection device externally located at the connection between the cable armor and the copper shell of the cable joint and outside the lead-lined cable. The external electromagnetic wave signal detection device identifies the device ID of the built-in electromagnetic wave signal generator to determine the signal source. The electromagnetic wave signal generator inside the copper shell of the cable joint emits electromagnetic waves, and the diffraction effect of electromagnetic waves penetrating through metal gaps is used to detect whether the lead-lined cable is damaged. If the metal cavity composed of the copper shell of the cable joint, the cable armor, and the lead-lined cable is damaged, the external electromagnetic wave signal detection device can detect the electromagnetic waves from the built-in device, proving that electromagnetic wave penetration has occurred at the cable joint, and that the lead-lined cable shell of the cable joint and the cable armor are damaged.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electricity and automatic control equipment technology, and specifically to a cable joint lead-lined damage detection device and method that utilizes the electromagnetic wave penetration effect. Background Technology

[0002] At high-voltage cable joints, the cable joint and the outer sheath of the cable body are connected using lead-lined technology. Due to factors such as cable gravity, underground settlement, and cable tension, the lead-lined lining frequently breaks down. This damage leads to water ingress into the cable joint, causing localized current discharge within the outer sheath, ultimately resulting in joint failure, cable head rupture, power outages, and disruptions to public life, causing significant economic losses.

[0003] Traditional methods for detecting lead-lined cable joint damage include eddy current testing and X-ray technology. Eddy current testing suffers from several drawbacks. The outer sheath of the cable's lead-lined surface is covered by a 5mm thick heat-shrink tubing, and the irregular shape of the lead-lined area results in a large and uneven contact distance between the eddy current probe and the cable's lead-lined surface. This directly leads to inaccurate detection and a high false alarm rate. Furthermore, because eddy current testing requires continuous probe movement to ensure thorough detection of every corner around the lead-lined surface, it cannot be used for online inspection and is best suited for manual inspection.

[0004] X-ray technology is expensive to inspect and causes irreversible aging to the rubber structure inside the cable during operation, shortening the cable's lifespan. Therefore, it is not suitable for online inspection.

[0005] Through years of research and practice on the aforementioned technologies, the applicant discovered that after the copper shell of the high-voltage cable armor and joint is lined with lead, a sealed metal cavity is formed. This cavity effectively shields electromagnetic wave signals. However, when the lead lining is damaged, electromagnetic wave signals can penetrate the originally sealed cavity through diffraction and other means. Utilizing this principle, the applicant developed a detection method that uses the electromagnetic wave penetration effect to detect whether the lead lining of the high-voltage cable armor and joint is damaged. Simultaneously, the applicant studied whether high-frequency or low-frequency electromagnetic waves are more likely to penetrate when the lead lining of the cable is damaged, especially when the gap is extremely small; and investigated how to solve the power supply problem with the built-in electromagnetic wave signal transmitting unit. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a cable joint lead-lined damage detection device and method utilizing the electromagnetic wave penetration effect. By utilizing the electromagnetic wave penetration and diffraction effect through metal gaps, when the metal cavity composed of the copper shell, cable armor, and lead lining of the cable joint is damaged, the detection device located at the copper shell and armor joint of the cable joint can detect the electromagnetic waves of the internal device, thus proving that electromagnetic wave penetration has occurred at the cable joint, and that the copper shell and lead lining of the cable armor are damaged.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] This invention first provides a cable joint lead-lined damage detection device utilizing the electromagnetic wave penetration effect. The detection device mainly includes an electromagnetic wave signal generator built into the copper shell of the cable joint, a power extraction unit built into the copper shell of the cable joint, and an electromagnetic wave signal detection device placed outside the connection between the cable armor and the copper shell of the cable joint and outside the cable lead-lined layer, for detecting the cable lead-lined layer at the connection between the copper shell of the cable joint and the cable armor.

[0009] Preferably, the electromagnetic wave signal generator is built into the copper shell of the cable connector, forming a closed metal cavity with the inductor armor and lead-lined layer.

[0010] In any of the above technical solutions, it is preferred that the electromagnetic wave signal generator is used to transmit electromagnetic wave signals, and it is equipped with an electromagnetic wave signal antenna with directional transmission function, which can transmit electromagnetic wave frequencies of 2.4 GHz, 433 MHz or 315 MHz.

[0011] In any of the above technical solutions, it is preferred that the electromagnetic wave signal generator is equipped with one or more sets of transmitters to achieve multi-angle signal transmission coverage.

[0012] In any of the above technical solutions, it is preferred that the electromagnetic wave signal generator is equipped with an encoding and transmission module to transmit the identification device ID.

[0013] In any of the above technical solutions, it is preferred that the electromagnetic wave signal generator is equipped with a microcontroller to realize the transmission encoding and transmission time power consumption control signals.

[0014] In any of the above technical solutions, it is preferred that the power extraction unit adopts an electromagnetic inductor unit, which uses the alternating current of the high-voltage cable to obtain electrical energy through a current transformer.

[0015] In any of the above technical solutions, it is preferred that the power supply unit is installed inside a closed metal cavity composed of a copper shell of the cable connector, an inductor armor, and a lead-lined layer, to provide power to the electromagnetic wave signal generator.

[0016] In any of the above technical solutions, it is preferred that the power collection unit uses a capacitor to store electrical energy to collect weak current, and it is connected to the electromagnetic wave signal generator to provide sufficient power to the electromagnetic wave signal generator.

[0017] In any of the above technical solutions, it is preferred that the power supply unit is connected to a microcontroller, and the power supply control is realized through the microcontroller.

[0018] In any of the above technical solutions, it is preferred that the electromagnetic wave signal detection device is installed on the outside of the copper shell and lead-lined parts of the cable armor and cable joint.

[0019] In any of the above technical solutions, it is preferred that the electromagnetic wave signal detection device is one or more sets of receivers to achieve multi-angle signal reception coverage.

[0020] In any of the above technical solutions, it is preferred that the electromagnetic wave signal detection device is equipped with a wireless communication module, an optical fiber communication module, an industrial control bus, or an Ethernet communication module.

[0021] In any of the above technical solutions, it is preferred that the electromagnetic wave signal detection device and the electromagnetic wave signal generator are matched with each other. The electromagnetic wave signal detection device, which is externally mounted on the copper shell and lead-lined shell of the cable armor and cable joint, identifies the device ID of the electromagnetic wave signal generator built into the copper shell of the cable joint and determines the source of the signal.

[0022] This invention also provides a method for detecting lead-lined damage to cable joints using the electromagnetic wave penetration effect, employing the cable joint lead-lined damage detection device as described in any of the preceding claims. The detection method includes:

[0023] Lead-lined connection is applied to the copper shell of the high-voltage cable armor and cable joint, forming a closed metal cavity with the copper shell of the cable joint, the connection point of the cable armor, and the lead-lined layer. An electromagnetic wave signal generator and a power extraction unit are installed inside the copper shell of the cable joint, while an electromagnetic wave signal detection device is externally located at the connection point of the cable armor and the copper shell of the cable joint, and outside the lead-lined layer. The power extraction unit provides power to the electromagnetic wave signal generator, and the external electromagnetic wave signal detection device identifies the electromagnetic wave signal embedded in the copper shell of the cable joint. The device ID of the signal generator is used to determine the signal source. Electromagnetic waves are emitted by an electromagnetic wave signal generator built into the copper shell of the cable joint. The electromagnetic waves are used to detect whether the lead enamel is damaged by the diffraction effect of the electromagnetic waves penetrating through the metal gaps. If the metal cavity composed of the copper shell of the cable joint, the cable armor, and the lead enamel is damaged, the electromagnetic wave signal detection device placed outside the connection between the cable armor and the copper shell of the cable joint and outside the lead enamel of the cable can detect the electromagnetic waves of the built-in electromagnetic wave signal generator, proving that electromagnetic wave penetration has occurred at the cable joint and that the copper shell of the cable joint and the lead enamel of the cable armor are damaged.

[0024] Compared to traditional eddy current testing and X-ray inspection techniques for detecting damage to the lead-lined parts of cable joints, the present invention employs a cable joint lead-lined damage detection device and method that utilizes the electromagnetic wave penetration effect. By leveraging the diffraction effect of electromagnetic waves penetrating metal gaps, when the metal cavity composed of the copper shell, cable armor, and lead lining of the cable joint is damaged, the detection equipment located at the copper shell and armor joint of the cable joint can detect the electromagnetic waves from the internal equipment, proving that electromagnetic wave penetration has occurred at the cable joint, and that there is damage to the copper shell and lead lining of the cable armor. This technical solution has the advantages of lower cost, higher reliability, faster detection, lower power consumption, and ease of online detection. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the detection device structure of a preferred embodiment of the cable joint lead-lined damage detection device utilizing the electromagnetic wave penetration effect according to the present invention.

[0027] Reference numerals: 1. Lead enamel, 2. Power supply unit, 3. Transmitter, 4. Receiver. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To overcome the problems existing in the detection of lead-lined cable joint damage in the prior art, this invention proposes a detection device and method for detecting lead-lined cable joint damage using the electromagnetic wave penetration effect. Compared with the prior art, this online detection technology is lower in cost, more reliable, and faster.

[0030] The cable joint lead-lined damage detection device utilizing the electromagnetic wave penetration effect described in this embodiment has the following structure: Figure 1As shown, it mainly consists of an electromagnetic wave signal generator built into the copper shell of the cable joint, a power extraction unit (2) built into the copper shell of the cable joint, and an electromagnetic wave signal detection device placed outside the connection between the cable armor and the copper shell of the cable joint and the lead enamel of the cable (1). It uses the electromagnetic wave penetration effect to detect whether the lead enamel (1) of the high-voltage cable armor and joint is damaged.

[0031] The detection device described in this embodiment has an electromagnetic wave signal generator built into the copper shell of the cable connector, which together with the inductor armor and lead enamel (1) forms a closed metal cavity.

[0032] The detection device described in this embodiment includes an electromagnetic wave signal generator for transmitting electromagnetic wave signals. It is equipped with an electromagnetic wave signal antenna with directional transmission function, and preferably transmits electromagnetic wave frequencies of 2.4 GHz, 433 MHz, or 315 MHz.

[0033] The detection device described in this embodiment has one or more sets of transmitters (3) in the electromagnetic wave signal generator to achieve multi-angle signal transmission coverage.

[0034] The detection device described in this embodiment includes an electromagnetic wave signal generator with an encoding transmission module. The electromagnetic wave signal generator has an encoding transmission function and can identify the device ID.

[0035] The detection device described in this embodiment uses a microcontroller-controlled electromagnetic wave signal generator to implement transmission encoding and transmission time / power consumption control signals. The electromagnetic wave signal generator, controlled by a microcontroller chip, can achieve transmission encoding and transmission time / power consumption control.

[0036] The detection device described in this embodiment uses an electromagnetic inductance unit (2) to obtain electrical energy through a current transformer by utilizing the alternating current of a high-voltage cable.

[0037] The detection device described in this embodiment has a power supply unit (2) installed inside a metal closed cavity composed of a copper shell of a cable connector, an inductor armor, and a lead-lined (1) layer, which provides power to the electromagnetic wave signal generator.

[0038] The detection device described in this embodiment uses a capacitor to store electrical energy in the power collection unit (2) to collect weak current. It is connected to the electromagnetic wave signal generator and is controlled by a single-chip microcomputer to provide sufficient power to the electromagnetic wave signal generator.

[0039] In the detection device described in this embodiment, the power supply unit (2) is connected to a microcontroller, and the power supply control is realized through the microcontroller.

[0040] The detection device described in this embodiment, the electromagnetic wave signal detection equipment, is installed on the outside of the copper shell and lead-lined (1) part of the cable armor and cable joint.

[0041] The detection device described in this embodiment is an electromagnetic wave signal detection device consisting of one or more receivers (4) to achieve multi-angle signal reception coverage.

[0042] The detection device described in this embodiment includes an electromagnetic wave signal detection equipment equipped with a wireless communication module, an optical fiber communication module, an industrial control bus, or an Ethernet communication module. The electromagnetic wave signal detection equipment supports wireless, optical fiber, industrial control bus, and Ethernet communication for signal transmission.

[0043] In this embodiment, the detection device is matched with the electromagnetic wave signal generator. The electromagnetic wave signal detection device, externally mounted on the copper shell and lead-lined (1) of the cable armor and cable joint, identifies the device ID of the electromagnetic wave signal generator built into the copper shell of the cable joint to determine the signal source. The electromagnetic wave signal detection device identifies the built-in electromagnetic wave signal generator ID to determine the signal source device.

[0044] Lead enamel (1) is applied to the copper shell of the high-voltage cable armor and the cable joint. The connection between the cable joint copper shell, the cable armor, and the lead enamel (1) layer forms a closed metal cavity. An electromagnetic wave signal generator, a power extraction unit (2), and an electromagnetic wave signal detection device are installed inside the cable joint copper shell, and outside the connection between the cable armor and the cable joint copper shell and the lead enamel (1). The power extraction unit (2) provides power to the electromagnetic wave signal generator. The electromagnetic wave signal detection device outside the cable armor, the cable joint copper shell, and the lead enamel (1) identifies the electromagnetic wave signal inside the cable joint copper shell. The device ID of the electromagnetic wave signal generator is used to determine the signal source. Electromagnetic waves are emitted by the electromagnetic wave signal generator built into the copper shell of the cable joint. The electromagnetic waves are used to detect whether the lead enamel (1) is damaged by the penetration and diffraction effect of the electromagnetic waves through the metal gaps. If the metal cavity composed of the copper shell of the cable joint, the cable armor, and the lead enamel (1) is damaged, the electromagnetic wave signal detection device placed outside the connection between the cable armor and the copper shell of the cable joint and outside the lead enamel (1) of the cable can detect the electromagnetic waves of the built-in electromagnetic wave signal generator, proving that electromagnetic wave penetration has occurred at the cable joint and that the copper shell of the cable joint and the lead enamel (1) of the cable armor are damaged. Among them, the electromagnetic wave signal generator is equipped with multiple sets of transmitters (3) to realize multi-angle signal transmission coverage in the detection process; the electromagnetic wave signal detection device is equipped with multiple sets of receivers (4) to realize multi-angle signal reception coverage in the detection process.

[0045] This embodiment employs a cable joint lead-lined enamel damage detection device and method utilizing the electromagnetic wave penetration effect. The detection device mainly includes an electromagnetic wave signal generator built into the copper shell of the cable joint, a power extraction unit built into the copper shell of the cable joint, and an electromagnetic wave signal detection device externally positioned at the connection between the cable armor and the copper shell of the cable joint, and outside the lead-lined enamel of the cable. The external electromagnetic wave signal detection device identifies the device ID of the built-in electromagnetic wave signal generator to determine the signal source. The electromagnetic wave signal generator inside the copper shell of the cable joint emits electromagnetic waves, utilizing the penetration and diffraction effect of electromagnetic waves through metal gaps to detect whether the lead-lined enamel is damaged. If the metal cavity composed of the copper shell of the cable joint, the cable armor, and the lead-lined enamel is damaged, the external electromagnetic wave signal detection device can detect the electromagnetic waves from the built-in device, proving that electromagnetic wave penetration has occurred at the cable joint, and that there is damage to the lead-lined enamel of the cable joint and the cable armor. Compared with traditional eddy current testing and X-ray inspection techniques for damage to the lead-lined enamel of cable joints, this technical solution has the advantages of lower cost, higher reliability, faster detection, lower power consumption, and ease of online detection.

[0046] In practice, after multiple tests, it was found that the internal space of the cable joint, based on the antenna design required by the electromagnetic waves, is suitable for designing electromagnetic wave signal transmission units with a frequency of 1MHz or higher.

[0047] In practice, through comparative testing, it was found that the copper shell of the cable joint has a strong absorption capacity for low-frequency electromagnetic waves, making it difficult for wireless signals to penetrate the gaps in the copper shell. High-frequency electromagnetic waves, on the other hand, have a relatively strong penetrating ability and can be easily detected on the outside of any lead-lined damage.

[0048] In practice, to meet national electromagnetic wave standards, the signal frequencies for the electromagnetic wave transmission unit are set at 2.4 GHz, 433 MHz, and 315 MHz. 2.4 GHz is the preferred frequency.

[0049] In practice, a power extraction module was specially designed to provide power to the transmitting module. This power extraction module uses the principle of current inductance to obtain energy by sensing the current in the cable core wires.

[0050] In practice, considering the need to integrate the power extraction unit into the copper shell of the cable connector, the size of the power extraction unit needs to be designed to be relatively small. Therefore, a capacitor is used to store electrical energy. By aggregating the small current from the power extraction unit, when the energy reaches a certain threshold, the electromagnetic wave transmitting unit is activated to send electromagnetic wave signals.

[0051] In practice, to identify the source of electromagnetic wave signals and avoid misjudgments, a microcontroller was used to control both the power extraction unit and the electromagnetic wave signal transmission unit. The power extraction unit was configured to determine the collection of small currents and energy thresholds, as well as control the transmission time. The electromagnetic wave signal transmission unit was configured with signal encoding control.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention; the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention; any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A cable joint lead-lined lining damage detection device utilizing the electromagnetic wave penetration effect, used for detecting the lead-lined lining of cables at the connection between the copper shell and the cable armor of the cable joint, characterized in that: The detection device comprises an electromagnetic wave signal generator built in the copper shell of the cable joint, a power taking unit built in the copper shell of the cable joint, and an electromagnetic wave signal detection device externally arranged at the connection between the cable armor and the copper shell of the cable joint and outside the cable lead. The electromagnetic wave signal generator is built in a metal closed cavity composed of the copper shell of the cable joint, the cable armor and the lead, and is used for sending electromagnetic wave signals. The electromagnetic wave signal generator sends electromagnetic wave signals at a frequency of 2.4 GHz, 433 MHz or 315 MHz. The power taking unit is installed inside the metal closed cavity composed of the copper shell of the cable joint, the cable armor and the lead, and provides power for the electromagnetic wave signal generator. The electromagnetic wave signal generator is provided with a coding sending module for sending an identification device ID. The electromagnetic wave signal generator is also provided with a single-chip microcomputer for realizing sending coding and sending time power consumption control signals. The electromagnetic wave signal detection device is matched with the electromagnetic wave signal generator. The electromagnetic wave signal detection device externally arranged at the connection between the cable armor and the copper shell of the cable joint and outside the lead identifies the device ID of the electromagnetic wave signal generator built in the copper shell of the cable joint, and judges the signal source.

2. The cable joint lead damage detecting apparatus using the electromagnetic wave penetration effect according to Claim 1, wherein: The electromagnetic wave signal generator is provided with one or more groups of transmitters for realizing multi-angle signal sending coverage.

3. The cable joint lead damage detecting apparatus using electromagnetic wave penetration effect according to Claim 1, wherein: The power taking unit adopts an electromagnetic mutual inductance unit, utilizes the alternating current of the high-voltage cable, and obtains power through a current transformer. The power taking unit adopts a capacitor for storing power, realizes weak current collection, and is connected with the electromagnetic wave signal generator for providing sufficient power for the electromagnetic wave signal generator. The power taking unit is connected with the single-chip microcomputer, and realizes power taking control through the single-chip microcomputer.

4. The cable joint lead damage detecting apparatus using electromagnetic wave penetration effect according to claim 1, characterized by: The electromagnetic wave signal detection device is installed outside the cable armor, the copper shell of the cable joint and the lead. The electromagnetic wave signal detection device is provided with a wireless communication module, an optical fiber communication module, an industrial control bus or an Ethernet communication module.

5. The cable joint lead damage detecting apparatus using electromagnetic wave penetration effect according to claim 4, characterized by: The electromagnetic wave signal detection device is provided with one or more groups of receivers for realizing multi-angle signal receiving coverage.

6. A method for detecting damage of a lead of a cable joint using electromagnetic wave penetration effect, which employs the apparatus for detecting damage of a lead of a cable joint using electromagnetic wave penetration effect according to any one of claims 1 to 5, characterized by, The detection method comprises: carrying out leaded enclosure linking treatment on the cable armor of the high-voltage cable and the copper shell of the cable joint, the copper shell of the cable joint, the cable armor and the leaded enclosure forming a metal closed cavity; setting an electromagnetic wave signal generator built in the copper shell of the cable joint, a power taking unit built in the copper shell of the cable joint and an electromagnetic wave signal detection device externally arranged at the connection part of the cable armor and the copper shell of the cable joint and outside the cable leaded enclosure, the power taking unit providing power for the electromagnetic wave signal generator, the electromagnetic wave signal detection device externally arranged at the connection part of the cable armor and the copper shell of the cable joint and outside the cable leaded enclosure identifying the equipment ID of the electromagnetic wave signal generator built in the copper shell of the cable joint and judging the signal source; emitting electromagnetic waves by the electromagnetic wave signal generator built in the copper shell of the cable joint, utilizing the penetration and diffraction effect of the electromagnetic waves on the metal gap, detecting whether the leaded enclosure is damaged, if the metal cavity formed by the copper shell of the cable joint, the cable armor and the leaded enclosure is damaged, the electromagnetic wave signal detection device externally arranged at the connection part of the cable armor and the copper shell of the cable joint and outside the cable leaded enclosure can detect the electromagnetic waves of the built-in equipment, proving that the electromagnetic wave penetration phenomenon occurs at the cable joint, and the copper shell of the cable joint and the cable armor leaded enclosure are damaged.

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