A small amplitude traveling wave current initiated fault location device

Abstract

The utility model provides a kind of small amplitude traveling wave current starting's fault location device, belong to electric power monitoring equipment technical field, the device includes acquisition device, acquisition device includes base body and two oppositely arranged snap rings, and the snap joint position is formed between two snap rings;Two relatively movable connecting arms are provided in base body, each connecting arm is fixedly connected with a snap ring, a pressing block is provided on each connecting arm, and each pressing block is exposed outside base body. Current transformer is provided in snap ring, and two connecting ends are provided on current transformer;PCB board is provided in base body, current transformer is electrically connected with PCB board, signal conditioning structure and microprocessor are further provided on PCB board, and signal conditioning structure includes preamplifier and filter circuit. The fault location device is easy to install, and small amplitude traveling wave current can be collected, effective accurate positioning of the fault of transmission line is realized, so as to save the detection time of transmission line.

Description

Technical Field

[0001] This utility model relates to the field of power monitoring equipment technology, and in particular to a fault location device that is initiated by a small-amplitude traveling wave current. Background Technology

[0002] Traveling wave fault location equipment is used to quickly and accurately locate fault points in power lines (including cables). Its working principle is mainly based on traveling wave theory: when a power line fault occurs, a voltage pulse is generated at the fault point. This pulse propagates in the cable or line as a traveling wave. By analyzing the propagation characteristics, reflection characteristics, and waveform features of these traveling waves, the location of the fault point can be determined. Existing traveling wave current fault location devices suffer from insufficient accuracy in capturing small-amplitude traveling wave current signals. Due to the complex line structure and variable operating environment in power systems, interference signals can easily be mixed into the traveling wave current, making it difficult to accurately identify and collect small-amplitude fault traveling wave current signals. Furthermore, existing traveling wave fault location equipment often uses Rogowski coils, which need to be installed around conductors. When modifying existing transmission lines, power must be shut down and the conductors removed, making construction complex and costly.

[0003] Therefore, existing traveling wave fault location equipment needs to be improved to overcome the shortcomings of the existing technology. Utility Model Content

[0004] To overcome the problems existing in related technologies, one of the objectives of this application is to provide a fault location device that is initiated by a small-amplitude traveling wave current. This fault location device is easy to install and can collect small-amplitude traveling wave currents to achieve effective and accurate fault location of transmission lines, thereby saving the detection time of transmission lines.

[0005] A fault location device initiated by a small-amplitude traveling wave current includes:

[0006] A data acquisition device includes a base and two opposing retaining rings, with a retaining position formed between the two retaining rings; the base has two relatively movable connecting arms, each connecting arm is fixedly connected to one of the retaining rings, and each connecting arm has a pressing block, with each pressing block exposed outside the base;

[0007] A current transformer is provided in the retaining ring, and the current transformer has two connection terminals; a PCB board is provided in the substrate, and the two connection terminals of the current transformer are electrically connected to the PCB board. A signal conditioning structure and a microprocessor are also provided on the PCB board. The signal conditioning structure includes a preamplifier and a filter circuit, and the preamplifier and the filter circuit are both electrically connected to the PCB board.

[0008] In a preferred embodiment of this invention, the retaining rings are semi-circular in shape, and anti-slip surfaces are provided on the opposite side walls of the two retaining rings, with anti-slip textures on the anti-slip surfaces.

[0009] In a preferred embodiment of this utility model, one end of the connecting arm is provided with a first connecting block, the first connecting block is provided with a slot, one end of the retaining ring is provided with a second connecting block, the second connecting block is provided with an insert block, and the insert block is adapted to the slot;

[0010] The first connecting block is also provided with a first threaded hole, and the second connecting block is provided with a second threaded hole, the second threaded hole corresponding to the first threaded hole.

[0011] In a preferred embodiment of this utility model, the substrate is provided with an installation cavity, the connecting arms are relatively movable and disposed in the installation cavity, each connecting arm is provided with an elastic element, the axial direction of the elastic element is the same as the moving direction of the connecting arm, one end of the elastic element abuts against the connecting arm, and the opposite end abuts against the side wall of the installation cavity;

[0012] The side wall of the mounting cavity is also provided with a passage, and the pressing block passes through the passage and protrudes from the body. Pressing the pressing block can cause the two retaining rings to move away from each other.

[0013] In a preferred embodiment of this invention, a shielding box is provided inside the mounting cavity, the PCB board is disposed in the shielding box, and a wireless communication module is also provided on the PCB board, wherein the wireless communication module is either a Bluetooth module or a wireless radio frequency module.

[0014] In a preferred embodiment of this invention, an energy harvesting coil is provided in the substrate, and the energy harvesting coil is electrically connected to the PCB board; when the fault location device is installed on the line, the energy harvesting coil obtains energy from the line.

[0015] In a preferred embodiment of this invention, a storage battery is disposed in the substrate, and a solar panel is disposed on the outer wall of the substrate. The solar panel and the energy harvesting coil are electrically connected to the storage battery, and the storage battery is electrically connected to the PCB board.

[0016] In a preferred embodiment of this invention, an auxiliary fixing band is further provided on the substrate, and the auxiliary fixing band is provided with two adhesive joints that can be bonded to each other.

[0017] The beneficial effects of this utility model are as follows:

[0018] This utility model provides a fault location device initiated by a small-amplitude traveling wave current. The device includes a data acquisition unit, which comprises a base and two opposing retaining rings forming a snap-fit ​​connection. The base contains two relatively movable connecting arms, each fixedly connected to one retaining ring. Each connecting arm has a pressing block, which protrudes from the base. A current transformer with two connecting terminals is housed within the retaining rings. A PCB board is embedded in the base, electrically connected to the current transformer. The PCB board also contains a signal conditioning structure and a microprocessor. The signal conditioning structure includes a preamplifier and a filter circuit, both electrically connected to the PCB board. When installing this fault location device, the operator presses two pressing blocks by hand, causing the two connecting arms to move the retaining rings away from each other, opening the locking position. Then, the acquisition device is placed at the location of the transmission line to be monitored. Releasing the pressing blocks allows the connecting arms to reset, causing the retaining rings to move closer together, thus securing the retaining rings tightly onto the transmission line. The entire installation process requires no additional tools and is simple and convenient. When a fault occurs in the transmission line, a small-amplitude traveling wave current generated at the fault point propagates along the transmission line. The current transformer inside the retaining ring senses the traveling wave current signal and converts it into a weak electrical signal, which is transmitted to the signal conditioning structure on the PCB board through the connecting terminal. The preamplifier amplifies the weak electrical signal, and the filter circuit further filters out interference signals to obtain a relatively pure traveling wave current signal. After being converted into a digital signal by the A / D conversion module, the microprocessor analyzes and calculates the digital signal, extracting parameters such as the arrival time and waveform characteristics of the traveling wave current to calculate the location of the fault point. This device is easy to install, requiring no complex operations such as power outages or disconnections of transmission lines, greatly saving installation time and labor costs. It also reduces the impact on normal line operation during installation, improving the efficiency and safety of power maintenance. The device can sense small-amplitude traveling wave currents generated in transmission lines, solving the problem of not being able to collect small traveling wave currents not caused by lightning strikes in existing technologies. This allows for the timely detection of early or minor faults, providing the possibility for early warning and handling of faults. Attached Figure Description

[0019] Figure 1 This is a first perspective view of the fault location device initiated by a small-amplitude traveling wave current provided in an embodiment of this utility model;

[0020] Figure 2 This is a front view of the fault location device initiated by a small-amplitude traveling wave current provided in an embodiment of this utility model;

[0021] Figure 3 This is a second perspective view of the fault location device initiated by a small-amplitude traveling wave current provided in an embodiment of this utility model;

[0022] Figure 4 This is a schematic diagram of the connection between the current transformer and the PCB provided in an embodiment of this utility model;

[0023] Figure 5 This is a schematic diagram showing the connection between the energy harvesting coil, the solar panel, and the storage battery provided in an embodiment of this utility model.

[0024] Figure label:

[0025] 1. Base; 11. Through port; 12. Mounting cavity; 2. Snap ring; 21. Snap-fit ​​position; 22. Second connecting block; 23. Second threaded hole; 24. Anti-slip surface; 3. Pressing block; 4. Current transformer; 5. Elastic element; 6. Shielding box; 7. Connecting arm; 71. First connecting block; 8. Energy harvesting coil; 81. Storage battery; 82. Solar panel; 9. PCB board; 91. Preamplifier; 92. Filtering circuit; 93. Microprocessor; 94. Wireless communication module. Detailed Implementation

[0026] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0027] Existing traveling wave current fault location devices suffer from insufficient accuracy in capturing small-amplitude traveling wave current signals. Due to the complex line structures and variable operating environments in power systems, interference signals easily mix into the traveling wave current, making it difficult to accurately identify and collect small-amplitude fault traveling wave current signals. Furthermore, existing traveling wave fault location devices often use Rogowski coils, which require installation around conductors. When retrofitting existing transmission lines, this necessitates power outages and conductor removal, resulting in complex and costly construction.

[0028] Based on this, this application provides a fault location device that is started by a small-amplitude traveling wave current.

[0029] Example

[0030] like Figures 1-5 As shown, this application provides a fault location device initiated by a small-amplitude traveling wave current, comprising:

[0031] The acquisition device includes a base 1 and two oppositely arranged retaining rings 2, with a retaining position 21 formed between the two retaining rings 2; the base 1 is provided with two relatively movable connecting arms 7, each connecting arm 7 is fixedly connected to one of the retaining rings 2, and each connecting arm 7 is provided with a pressing block 3, each pressing block 3 is exposed outside the base 1;

[0032] The retaining ring 2 is provided with a current transformer 4, which has two connection terminals; the base 1 is provided with a PCB board 9, and both connection terminals of the current transformer 4 are electrically connected to the PCB board 9. The PCB board 9 is also provided with a signal conditioning structure and a microprocessor 93. The signal conditioning structure includes a preamplifier 91 and a filter circuit 92, both of which are electrically connected to the PCB board 9.

[0033] Specifically, in practical applications, a return spring is provided on the connecting arm 7. When the pressing block 3 is not subjected to external force, the return spring keeps the two retaining rings 2 in a closed state. When the pressing block 3 is pressed, the two retaining rings 2 move away from each other, and the locking position 21 is opened. In addition, the current transformer 4 of this application includes a Rogowski coil. The Rogowski coil (wound using a flexible printed circuit board FPC and covered with insulating silicone material) inside the retaining ring 2 opens synchronously with the retaining ring 2. After the transmission line is placed in the locking position 21, the pressing block 3 is released, and the retaining ring 2 closes under the action of the spring, and the Rogowski coil tightly wraps around the outer periphery of the transmission line. The two ends of the Rogowski coil are connected to the PCB board 9 through a miniature coaxial cable. The connection point uses a waterproof SMB RF connector to ensure the stability of signal transmission. The coil adopts a dual-wire parallel winding structure, which effectively suppresses common-mode interference. Its self-integration time constant is designed to be 1ms, which can accurately respond to traveling wave current signals in the 10kHz-1MHz frequency band. The preamplifier 91 is a noise amplifier, and the filter circuit 92 is a bandpass filter.

[0034] When a fault occurs in a transmission line, generating a traveling wave current, the Rogowski coil induces a voltage signal proportional to the rate of change of current. This signal first passes through an impedance matching network (composed of a 50Ω resistor and a 10nF capacitor) on PCB board 9, and then enters a low-noise amplifier (using an AD8099 chip, with an input noise density of only 0.9nV / √Hz) for amplification. The amplified signal then passes through a bandpass filter (center frequency 200kHz, bandwidth 100kHz-500kHz) to filter out power frequency and harmonic interference. The filter uses a MAX7401 programmable switched-capacitor filter chip, and the cutoff frequency is dynamically adjusted by the MCU via the SPI interface. In a preferred embodiment, the filtered signal can be further amplified by a second-stage amplifier (gain 20dB) to reach the level range (0-3V) that the ADC can acquire. A high-speed analog-to-digital converter can also be set on the PCB board to digitize the signal. The converted digital signal is then subjected to wavelet transform by a DSP (TMS320F28335) to extract the characteristic parameters of the traveling wave signal (such as modulus maxima and arrival time). Finally, the microprocessor calculates the fault location using a dual-end time difference algorithm, and the location result is uploaded to the cloud server or the staff's mobile terminal via the wireless communication module 94 so that the staff can detect the abnormality of the line in a timely manner.

[0035] The aforementioned fault location device, triggered by a small-amplitude traveling wave current, requires the operator to press two pressing blocks 3 during installation. This causes the two connecting arms 7 to move the retaining rings 2 away from each other, opening the locking position 21. The acquisition device is then placed at the location of the transmission line to be monitored. Releasing the pressing blocks 3 allows the connecting arms 7 to reset, bringing the retaining rings 2 closer together and securing them tightly to the transmission line. The entire installation process requires no additional tools and is simple and convenient. When a fault occurs in the transmission line, a small-amplitude traveling wave current generated at the fault point propagates along the transmission line. The current transformer 4 inside the retaining ring 2 senses the traveling wave current signal and converts it into a weak electrical signal, which is transmitted to the signal conditioning structure on the PCB board 9 through the connecting terminal. The preamplifier 91 amplifies the weak electrical signal, and the filter circuit 92 further filters out interference signals, resulting in a relatively pure traveling wave current signal. After being converted into a digital signal by the A / D conversion module, the microprocessor 93 analyzes and calculates the digital signal, extracting parameters such as the arrival time and waveform characteristics of the traveling wave current, and calculating the location of the fault point. This device is easy to install, eliminating the need for complex operations such as power outages or disconnections of transmission lines, greatly saving installation time and labor costs. It also reduces the impact on normal line operation during installation, improving the efficiency and safety of power maintenance. This device can sense small-amplitude traveling wave currents generated in transmission lines, solving the problem of not being able to collect small traveling wave currents not caused by lightning strikes in existing technologies. It can promptly detect early or minor faults, providing the possibility for early warning and handling of faults.

[0036] It should be noted that the algorithm used by the microprocessor 93 module in this application to calculate the location of the fault point is existing technology, such as the double-ended time difference algorithm used to calculate the fault location. Therefore, this application will not elaborate on its calculation process.

[0037] Furthermore, the retaining ring 2 is semi-circular, and anti-slip surface 24 is provided on the opposite side wall of the two retaining rings 2, and anti-slip texture is provided on the anti-slip surface 24.

[0038] The semi-circular retaining ring 2 can tightly fit the circular contour of the transmission line. Compared with retaining rings of other shapes, it has a larger wrapping area and more even force distribution. The anti-slip surface 24 and anti-slip texture significantly increase the friction between the retaining ring 2 and the line, allowing the device to be firmly installed on the transmission line even in various complex environments (such as strong winds and high temperatures), avoiding signal acquisition failure due to loosening and ensuring long-term stable operation of the device.

[0039] This application provides a specific connection method between the connecting arm 7 and the retaining ring 2. One end of the connecting arm 7 is provided with a first connecting block 71, and the first connecting block 71 is provided with a slot. One end of the retaining ring 2 is provided with a second connecting block 22, and the second connecting block 22 is provided with a plug, the plug being adapted to the slot.

[0040] The first connecting block 71 is also provided with a first threaded hole, and the second connecting block 22 is provided with a second threaded hole 23, which corresponds to the first threaded hole.

[0041] During the production of this device, the worker first aligns the insert of the retaining ring 2 with the slot of the connecting arm 7 and inserts it smoothly along the axial direction until the bottom surface of the insert is completely in contact with the bottom of the slot. At this point, the first threaded hole and the second threaded hole 23 are precisely aligned, and an internal hexagon head screw is screwed in from the top of the first connecting block 71. The preload of the threaded pair securely locks the two connecting blocks together.

[0042] This connection method ensures the installation stability of the connecting arm 7 and the retaining ring 2, thereby ensuring that the device can be used stably for a long time.

[0043] Furthermore, the base 1 is provided with a mounting cavity 12, and the connecting arms 7 are relatively movable in the mounting cavity 12. Each connecting arm 7 is provided with an elastic element 5. The axial direction of the elastic element 5 is the same as the moving direction of the connecting arm 7. One end of the elastic element 5 abuts against the connecting arm 7, and the other end abuts against the side wall of the mounting cavity 12.

[0044] The side wall of the mounting cavity 12 is also provided with a passage 11. The pressing block 3 passes through the passage 11 and is exposed outside the base 1. Pressing the pressing block 3 can cause the two retaining rings 2 to move away from each other.

[0045] Specifically, the elastic element 5 in this application is a spring, and 2-4 springs can be provided on the connecting arm 7.

[0046] During the installation of the transmission line, the operator presses down on the two pressing blocks 3 with both hands, applying pressure. At this time, the pressing blocks 3 drive the connecting arm 7 to overcome the spring force and move to both sides along the sliding groove of the mounting cavity 12, thereby causing the two retaining rings 2 to open away from each other. Once the retaining rings 2 are open enough to accommodate the transmission line, the line is placed in the clamping position 21. Then, the pressing blocks 3 are released, and under the action of the spring's restoring force, the connecting arm 7 drives the retaining rings 2 to quickly return to their original position, tightly wrapping the transmission line. The preload generated by the spring maintains a stable contact pressure between the retaining rings 2 and the line, achieving rapid clamping of the transmission line without additional manual operation, effectively ensuring the continuous and stable acquisition of the traveling wave current signal by the current transformer 4.

[0047] Furthermore, a shielding box 6 is provided inside the mounting cavity 12, and the PCB board 9 is disposed in the shielding box 6. A wireless communication module 94 is also provided on the PCB board 9. The wireless communication module 94 is either a Bluetooth module or a wireless radio frequency module.

[0048] Specifically, an independent rectangular shielding box 6 is installed inside the mounting cavity 12 of the substrate 1. This box is made of 0.8mm thick aluminum alloy sheet, stamped and formed, with its inner wall coated with conductive silver paste, resulting in a surface resistance of less than 0.1Ω. The shielding box 6 is fixed to the bottom of the mounting cavity 12 by four copper studs, maintaining electrical isolation from the substrate 1. A removable cover is provided on one side of the box, which is tightly connected to the box body via stainless steel clips, forming a complete Faraday cage structure when closed.

[0049] The PCB board 9 is horizontally mounted on an insulating bracket inside the shielding box 6. The bracket is made of polytetrafluoroethylene (PTFE) to ensure electrical insulation between the PCB board 9 and the shielding box 6. The front and rear ends of the shielding box 6 are respectively provided with signal interface windows and power interface windows.

[0050] In practical applications, either a Bluetooth 5.0 module (model HC-08) or a 433MHz wireless RF module (model FS1000A) is selected based on the application scenario. The module connects to the PCB board 9 via 2.54mm pitch pin headers. The antenna uses either a built-in PCB antenna or an external SMA interface antenna (which can be replaced depending on the site environment). In practical applications, the analog signal output from the current transformer 4 is introduced into the shielded box 6 via a shielded cable. The digital signal processing circuit on the PCB board 9 is isolated from the wireless communication module 94 using an opto-isolator (model 6N137) to prevent digital circuit noise from interfering with wireless signal transmission.

[0051] Furthermore, an energy harvesting coil 8 is provided in the substrate 1, and the energy harvesting coil 8 is electrically connected to the PCB board 9; when the fault location device is installed on the line, the energy harvesting coil 8 obtains energy from the line.

[0052] Furthermore, a storage battery 81 is provided in the substrate 1, and a solar panel 82 is also provided on the outer wall of the substrate 1. The solar panel 82 and the energy harvesting coil 8 are both electrically connected to the storage battery 81, and the storage battery 81 is electrically connected to the PCB board 9.

[0053] Specifically, when the device is installed on the power transmission line, the energy harvesting coil 8 and the solar panel 82 start working simultaneously. During the day when the line is operating normally, the energy harvesting coil 8 is the main power source, and the solar panel 82 stores excess electrical energy in the battery 81; at night or when the line current is low, the solar panel 82 supplies power if there is sufficient sunlight, and the battery 81 supplies power when there is insufficient sunlight.

[0054] More specifically, the structure and energy extraction process of energy extraction coil 8 are as follows:

[0055] An annular energy harvesting coil 8 is located inside the substrate 1 near the retaining ring 2. It uses a nanocrystalline soft magnetic material as its core and has an open core that opens and closes synchronously with the retaining ring 2. The primary winding of the energy harvesting coil 8 is made of multi-strand enameled wire with 500 turns. The secondary winding is connected to the power management module on the PCB board 9 via a rectifier and filter circuit 92. When the device is installed on the power transmission line, the retaining ring 2 closes, and the core of the energy harvesting coil 8 also closes, forming a complete magnetic circuit.

[0056] During normal operation of the transmission line, the alternating magnetic field generated by the line current passes through the magnetic core of the energy harvesting coil 8, inducing an AC voltage in the secondary winding according to the principle of electromagnetic induction. When the line current is 10A-1000A, the secondary output voltage of the energy harvesting coil 8 ranges from 3V to 20V. After rectification, filtering, and DC-DC conversion, a stable 5V DC voltage is output, directly powering the PCB board 9, while simultaneously supplying excess energy to the battery 81 for charging. For example, when the line current is 100A, the energy harvesting coil 8 can output approximately 2W of power. Besides meeting the real-time operating power consumption of the device (approximately 0.8W), the remaining energy charges the battery 81.

[0057] Furthermore, the substrate 1 is also provided with an auxiliary fixing strap, which has two adhesive joints that can be bonded to each other. The adhesive joints can be configured as Velcro.

[0058] Specifically, after the fault location device is initially fixed on the transmission line by the retaining ring 2, the operator will move the auxiliary fixing around the line, so that the auxiliary fixing band forms a closed fixing ring around the line, thereby providing auxiliary fixing for the base 1 and further improving the stability of the device.

[0059] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0060] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0061] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fault location device initiated by a small-amplitude traveling wave current, characterized in that, include: A data acquisition device includes a base and two opposing retaining rings, with a retaining position formed between the two retaining rings; the base has two relatively movable connecting arms, each connecting arm is fixedly connected to one of the retaining rings, and each connecting arm has a pressing block, with each pressing block exposed outside the base; A current transformer is provided in the retaining ring, and the current transformer has two connection terminals; a PCB board is provided in the substrate, and the two connection terminals of the current transformer are electrically connected to the PCB board. A signal conditioning structure and a microprocessor are also provided on the PCB board. The signal conditioning structure includes a preamplifier and a filter circuit, and the preamplifier and the filter circuit are both electrically connected to the PCB board.

2. The fault location device initiated by a small-amplitude traveling wave current according to claim 1, characterized in that: The retaining rings are semi-circular in shape, and anti-slip surfaces are provided on the opposite side walls of the two retaining rings. Anti-slip textures are provided on the anti-slip surfaces.

3. The fault location device initiated by a small-amplitude traveling wave current according to claim 2, characterized in that: One end of the connecting arm is provided with a first connecting block, and the first connecting block is provided with a slot. One end of the retaining ring is provided with a second connecting block, and the second connecting block is provided with a plug, the plug being adapted to the slot. The first connecting block is also provided with a first threaded hole, and the second connecting block is provided with a second threaded hole, the second threaded hole corresponding to the first threaded hole.

4. The fault location device initiated by a small-amplitude traveling wave current according to any one of claims 1-3, characterized in that: The base is provided with an installation cavity, and the connecting arms are movably disposed in the installation cavity. Each connecting arm is provided with an elastic element, the axis of which is in the same direction as the moving direction of the connecting arm. One end of the elastic element abuts against the connecting arm, and the other end abuts against the side wall of the installation cavity. The side wall of the mounting cavity is also provided with a passage, and the pressing block passes through the passage and protrudes from the body. Pressing the pressing block can cause the two retaining rings to move away from each other.

5. The fault location device initiated by a small-amplitude traveling wave current according to claim 4, characterized in that: A shielding box is provided inside the mounting cavity, and the PCB board is placed inside the shielding box. A wireless communication module is also provided on the PCB board, which is either a Bluetooth module or a wireless radio frequency module.

6. The fault location device initiated by a small-amplitude traveling wave current according to claim 1, characterized in that: An energy harvesting coil is provided in the substrate and is electrically connected to the PCB board; when the fault location device is installed on the line, the energy harvesting coil obtains energy from the line.

7. The fault location device initiated by a small-amplitude traveling wave current according to claim 6, characterized in that: A battery is installed in the substrate, and a solar panel is installed on the outer wall of the substrate. The solar panel and the energy harvesting coil are electrically connected to the battery, and the battery is electrically connected to the PCB board.

8. The fault location device initiated by a small-amplitude traveling wave current according to claim 1, characterized in that: The substrate is also provided with an auxiliary fixing band, and the auxiliary fixing band is provided with two adhesive joints that can be bonded to each other.

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