Drop-out fuse position monitoring method based on two-stage over-travel timing self-check

Abstract

The application relates to the technical field of power distribution network primary equipment position monitoring, and particularly discloses a drop-out fuse position monitoring method based on two-stage over-travel timing self-checking, which comprises the following steps: adjusting an adjustable initial position member to establish a closed reference relative displacement, setting the release of the compression amount of an elastic over-travel member as a mechanical timing reference source independent of a microswitch electric signal, calibrating a standard action timing and establishing a trailing edge retention verification reference; collecting a current monitoring relative displacement during a closed duration to perform reference drift monitoring; obtaining timing information through double-source low-power consumption latching when a fuse tube is released, performing timing cross-verification and trailing edge retention consistency diagnosis, and distinguishing and confirming drop-out, switch sticking, contact bounce or non-mechanical release false triggering. The application uses an elastic over-travel member as a mechanical timing reference source, realizes double-source cross self-checking of mechanical chain physical actions and electrical results.

Description

Technical Field

[0001] This invention relates to the field of primary equipment position monitoring technology in power distribution networks, specifically to a method for monitoring the position of drop-out fuses based on two-stage overtravel timing self-checking. Background Technology

[0002] Drop-out fuses are commonly used overcurrent protection devices in power distribution networks. They typically consist of an insulating support, a stationary contact, a moving contact, a fuse tube, and a lower rotating shaft. During normal operation, the fuse tube is held in place by the upper contact. After the fuse element melts due to a short circuit or overcurrent, the fuse tube rotates around the lower rotating shaft under the influence of gravity and the release mechanism, forming a visible break. Currently, power distribution network maintenance relies heavily on power outage information, fault indicators, and manual inspections to indirectly determine the fuse status, making it difficult to promptly confirm the actual drop-out condition of specific towers and fuses.

[0003] Existing technologies have disclosed solutions for gravity or tilt angle detection, switch-triggered wake-up, temperature and current-assisted judgment, wireless communication, positioning, and GIS display. However, for fixed-side installation schemes that use microswitches to directly detect the position of the fuse tube, there are still deep mechanical diagnostic problems that have not been solved by existing technologies. Existing solutions generally use the microswitch electrical signal as the sole basis for state judgment, but the microswitch can only characterize the instantaneous electrical result of contact opening and closing, and cannot reflect whether the mechanical chain has completed the predetermined physical holding process after the electrical result is generated. When the microswitch contacts bounce, although the edge of the electrical signal has been generated, the mechanical contacts repeatedly open and close in a very short time. Existing technologies rely solely on fixed delay debouncing and cannot distinguish the characteristics of the bouncing and the actual release electrical signal. More importantly, under wind load or external disturbance, the fuse tube may experience a false release phenomenon where it briefly detaches from the contact and then springs back to close. At this time, the micro switch may have generated a release edge, but the mechanical chain has not actually completed the release and holding. Existing tilt sensors measure the overall attitude of the fuse tube rather than the effective stroke of the micro switch drive chain, and therefore cannot identify this mechanical holding failure.

[0004] Furthermore, in low-power sleep mode, if the controller is only woken up by the edge of the microswitch, the historical timing information of the elastic element's release process cannot be reproduced. The controller cannot obtain complete evidence of whether the mechanical chain continues to be released after the edge occurs, resulting in a break in the diagnostic evidence chain. The closing gap and movement trajectory of fuses from different manufacturers vary, and after installation, there is a lack of quantifiable trigger points and overtravel calibration conditions that are tied to the inherent characteristics of the mechanical structure.

[0005] Therefore, there is an urgent need for a drop-out fuse position monitoring method based on two-stage overtravel timing self-checking to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by this invention is to divide the fuse tube closing stroke into a microswitch driving stroke and an elastic overstroke without changing the body of the drop-out fuse and the primary conductive structure, so that the microswitch always works within the safe stroke. At the same time, the relative displacement between the trigger rod and the driven seat is directly detected, and the fuse tube position and trigger mechanism abnormalities are identified by the relative displacement threshold signal and the order of the microswitch edges. During the closing period, the installation state drift is monitored, and the mechanical holding state is verified after release, so as to achieve complete mechanical action timing self-checking.

[0007] The technical solution of this invention to solve the above-mentioned technical problems is as follows: a method for monitoring the position of a drop-out fuse based on two-stage over-travel timing self-checking, specifically including the following steps: S1. Obtain the relative displacement between the trigger rod and the driven seat when the fuse tube is closed. Adjust the adjustable initial position component to make the driven seat drive the micro switch to complete the state switching and abut against the drive limit component, so that the remaining stroke of the fuse tube is converted into the compression amount of the elastic overstroke component to establish the relative displacement of the closing reference. The relative displacement of the closing reference is located within the preset closing interval. Set the release of the compression amount of the elastic overstroke component as a mechanical timing reference source independent of the micro switch electrical signal. Calibrate the standard action timing between the trigger of the mechanical timing reference source and the state edge of the micro switch. Establish a trailing edge holding verification reference during the actual release of the fuse tube, where the relative displacement is held below the displacement threshold after the state edge of the micro switch. Store the displacement threshold, the relative displacement of the closing reference, the timing verification parameters, and the drift monitoring threshold in a non-volatile memory. The timing verification parameters include the standard action timing, the trailing edge holding verification reference, the micro switch closed state reference value and the drop state reference value, the preset allowable range, and the preset timeout duration. The drift monitoring threshold includes the first allowable deviation value and the second allowable deviation value.

[0008] S2. During the continuous period when the fusible tube is in the closed state, the current relative displacement is collected at a preset period and compared with the relative displacement of the closed reference. The type of reference drift is identified according to the direction and degree of deviation of the current monitored relative displacement from the relative displacement of the closed reference: if the current monitored relative displacement is lower than the relative displacement of the closed reference and the absolute value of the deviation exceeds the first allowable deviation value, it is identified as preload loss type drift and a first type of installation failure warning is generated; if the current monitored relative displacement is higher than the relative displacement of the closed reference and the absolute value of the deviation exceeds the second allowable deviation value, it is identified as position offset type drift and a second type of installation failure warning is generated; after any type of installation failure warning is generated, subsequent drop judgment is stopped until the calibration operation is re-executed.

[0009] S3. During the release of the fuse tube, the relative displacement detection unit continuously monitors the relative displacement between the trigger rod and the driven seat to obtain the mechanical timing reference source state. When the real-time relative displacement of the release crosses the displacement threshold downward, the threshold comparison and timing latching unit records the mechanical timing reference trigger time and generates a first wake-up signal. When the micro switch has a state edge, the electrical signal edge time is recorded and a second wake-up signal is generated. The controller is woken up after latching the order and time difference between the mechanical timing reference trigger time and the electrical signal edge time. After the controller is woken up, it extracts the trailing edge holding state of the relative displacement after the electrical signal edge time. Based on the matching relationship between the order and time difference of the mechanical timing reference trigger time and the electrical signal edge time and the standard action timing, as well as the consistency between the trailing edge holding state and the trailing edge holding verification reference, the dual-source cross-verification of the mechanical timing reference source and the electrical signal and the trailing edge consistency diagnosis are performed to distinguish and confirm the drop, switch jamming, contact bounce or non-mechanical release false triggering, and generate event data including cross-verification results, trailing edge consistency diagnosis conclusions and diagnosis types.

[0010] A drop-out fuse position monitoring system based on two-stage overtravel timing self-calibration is used to implement a drop-out fuse position monitoring method based on two-stage overtravel timing self-calibration. Specifically, it includes: a field monitoring terminal and a back-end operation and maintenance platform. The field monitoring terminal is installed on the fixed support side of the drop-out fuse and includes a fixing component, a sealed housing, a trigger conversion component, a micro switch, a relative displacement detection unit, a threshold comparison and timing latching unit, a controller, a temperature and humidity unit, a positioning unit, a multi-mode communication unit, and a power supply unit. The back-end operation and maintenance platform includes a data server and a GIS operation and maintenance platform.

[0011] The beneficial effects of this invention are: 1. The elastic overtravel component is reconstructed from a passive buffer element into a mechanical timing reference source independent of the micro-switch electrical signal. This enables the mechanical chain physical action and electrical results to form a dual-source cross-verification during the release of the fuse tube, breaking through the limitation that a single electrical signal cannot reflect the effective travel of the drive chain. It can accurately locate whether the fault occurs in the fuse tube, the triggering mechanism, or the switch body.

[0012] 2. After the microswitch generates an electrical signal edge, the relative displacement of the elastic overtravel component is used as the verification basis for the actual release of the mechanical chain. A trailing edge retention verification benchmark and consistency diagnosis mechanism are established to effectively identify contact bounce and fuse false release, filling the blind spot in the diagnosis of mechanical retention failure caused by the existing technology relying only on instantaneous edge judgment.

[0013] 3. During the continuous closure of the fuse tube, the relative displacement reference drift is periodically monitored, and the identification of installation preload loss and position offset is moved to before release to avoid operation with faults; the threshold comparison and timing latch unit continuously latches the dual-source timing sequence during low-power sleep, so that the controller can obtain the complete evidence chain after waking up without continuously turning on the main controller. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the method described in Embodiments 1-4 of the present invention; Figure 2 This is a schematic diagram of the structure of the fixed-side two-stage overtravel trigger conversion component; Figure 3 Flowchart for installation calibration and location event handling; Figure 4 This is a schematic diagram of the timing and anomaly diagnosis of two-stage travel signals; Figure 5 This is a general framework diagram of the system described in Embodiment 5 of the present invention.

[0015] The following are the labeling instructions in the diagram: 1-Fuse tube, 2-Lower rotating shaft, 10-Fixing component, 11-Anti-slip clamping component, 12-Insulating pad, 13-Sealed housing, 20-Trigger conversion component, 21-Trigger rod, 211-Contact head, 213-Shoulder, 22-Driven seat, 23-Elastic overtravel component, 24-Adjustable initial position component, 25-Drive limit component, 26-Reset spring, 30-Micro switch, 41-Relative displacement detection unit, 411-Magnet, 412-Hall element, 42-Temperature and humidity unit, 43-Threshold comparison and timing latching unit, 50-Controller, 60-Positioning unit, 70-Multimode communication unit, 80-Power supply unit, 90-Data server, 100-GIS operation and maintenance platform. Detailed Implementation

[0016] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0017] Example 1 like Figure 1 As shown, this invention provides a method for monitoring the position of a drop-out fuse based on a two-stage overtravel timing self-check, specifically including the following steps: S1. Adjust the adjustable initial position component to make the driven seat press the micro switch against the drive limit component to establish the relative displacement of the closed reference; set the elastic overtravel component as a mechanical timing reference source independent of the micro switch electrical signal to calibrate the standard action timing; establish the trailing edge holding verification reference and save the displacement threshold, timing verification parameters, relative displacement of the closed reference and drift monitoring threshold. S2. Collect the current monitored relative displacement, compare the current monitored relative displacement with the closed reference relative displacement periodically, and if the drift monitoring threshold is exceeded, generate an installation failure warning and stop the drop judgment. S3. When the real-time relative displacement crosses the displacement threshold, a first wake-up signal is generated; when the microswitch has an edge, a second wake-up signal is generated; the timing sequence is latched and the controller is woken up; the trailing edge hold state is extracted; timing cross-validation and trailing edge consistency diagnosis are performed according to the timing verification parameters; the drop and the abnormality are distinguished; and event data containing the diagnostic type is generated.

[0018] like Figure 2 As shown, the fixing assembly 10 is mounted on the fixed support of the drop-out fuse via the anti-slip clamp 11 and the insulating pad 12. The sealed housing 13 is connected to the fixing assembly 10, and the trigger rod 21 and the driven seat 22 are coaxially arranged in the straight guide hole of the housing 13. An elastic overtravel member 23 is provided between the shoulder 213 of the trigger rod 21 and the driven seat 22. The driven seat 22 forms a pressing surface on the side facing the micro switch 30, and the annular step inside the housing 13 serves as a drive limiting member 25. The contact head 211 at the outer end of the trigger rod 21 contacts the non-conductive outer surface of the fuse tube 1. The relative displacement detection unit 41 spans between the trigger rod 21 and the driven seat 22, and includes a magnet 411 and a Hall element 412 respectively fixed on the trigger rod 21 and the driven seat 22.

[0019] like Figure 3 As shown, during the installation and calibration phase, steps S101 to S103 are executed: the fuse is installed and closed, the initial position component 24 is adjusted to allow the microswitch to complete switching and continue pressing to form the second stage overtravel, and the closing reference is saved. After calibration, the system enters the low-power monitoring state in step S104. When a release action occurs, step S105 reads the latched mechanical timing reference trigger time and the electrical signal edge time, and calculates the time difference. If the timing is consistent and the trailing edge hold verification reference is met, the system proceeds to step S107A via step S106A to confirm the drop; if the timing or state is inconsistent, the system proceeds to step S107B via step S106B to generate an abnormal event. Finally, step S109 saves the event and returns to the low-power state.

[0020] like Figure 4 As shown, during a normal drop, the real-time relative displacement is released and first crosses the displacement threshold downwards, with time t recorded. δ Then the microswitch is released, and time t is recorded. K , satisfying 0≤t K -t δ If the value is ≤ΔT and the switch remains in the drop state, it is confirmed as a normal drop. If δ has been released but K has not changed, it is determined that the microswitch is stuck or the driven seat has insufficient travel. If K changes but δ is still in the closed range, it is determined that the contact is bouncing or the circuit is abnormal. If δ fluctuates repeatedly within a small range while K remains unchanged, it is identified as external force vibration and is not considered a drop alarm.

[0021] Example 2 Preferably, in Embodiment 1, step S1 is specifically implemented through the following steps: S11. Two-stage travel closure benchmark calibration and documentation, specifically including: S111. Install the fixing component onto the fixed support of the drop-out fuse using the anti-slip clamp. Place an insulating pad between the anti-slip clamp and the fixed support to ensure that the housing and trigger conversion assembly are located outside the fuse tube's movement path, preventing mechanical interference between the fuse tube and the housing when it falls or rotates. This ensures the fuse tube is in the closed position, where the upper contact of the fuse tube reliably contacts the stationary contact, and the lower rotating shaft of the fuse tube remains fixed.

[0022] Adjust the position of the outer end of the trigger rod until it contacts the non-conductive outer surface of the fusible tube, generating a slight preload. At this point, an initial relative displacement is formed between the trigger rod and the driven seat. This initial relative displacement is acquired by a relative displacement detection unit, which uses a combination of a magnet and a Hall element. The magnet is fixed to the trigger rod, and the Hall element is fixed to the driven seat. The output voltage of the Hall element is converted from analog to digital to obtain the initial relative displacement value. The value of this initial relative displacement ranges from 0 mm to 5 mm, with a preferred value of 1 mm to 2 mm, representing the initial installation gap between the trigger rod and the driven seat.

[0023] S112. A rotatable or movable adjustable initial position component is provided. This component employs a threaded adjusting sleeve structure with a locking nut. Rotating the threaded adjusting sleeve clockwise pushes the trigger rod to move in a first direction toward the micro switch. During the movement of the trigger rod, its shoulder compresses the elastic overtravel component, which transmits the thrust to the driven seat, causing the driven seat to move synchronously in the same direction. The driven seat gradually approaches and presses against the pressing surface of the micro switch, actuating the micro switch until the micro switch completes its state switch. At this point, the micro switch output level jumps from a drop-down level to a closed level.

[0024] Continue fine-tuning the adjustable initial position component to move the driven seat further until it abuts against the drive limit component. The drive limit component is either an annular step inside the housing or a limit screw with a locking nut. The position of the drive limit component is set according to the micro switch product parameters, ensuring that the maximum displacement of the driven seat is not less than the reliable operating displacement of the micro switch and not greater than the allowable safe displacement. When the allowable safe displacement is 1.2mm, the maximum displacement of the driven seat is set to be no greater than 1.0mm.

[0025] S113. After the driven seat is mechanically blocked by the driving limiter, the adjustable initial position member continues to be adjusted along the first direction. At this time, the position of the driven seat is locked and no longer moves. The trigger rod continues to move in the first direction relative to the driven seat. The remaining closed stroke of the fuse tube is converted into the compression of the elastic overstroke member. The elastic overstroke member adopts a compression spring, and its stiffness coefficient ranges from 2N / mm to 10N / mm, with a preferred value of 5N / mm.

[0026] The transient relative displacement between the trigger rod and the driven seat is monitored in real time by a relative displacement detection unit. Adjustment stops when the transient relative displacement falls within a preset closed range. The lower limit of the preset closed range ranges from 0.3mm to 0.8mm, and the upper limit ranges from 1.0mm to 1.5mm, with a preferred closed range of 0.5mm to 1.2mm. Tightening the locking nut of the adjustable initial position component completes the position locking. The transient relative displacement after locking is recorded as the closed reference relative displacement, which is stored in a non-volatile memory as a comparison benchmark for drift monitoring during subsequent closed periods.

[0027] S12. Setting the mechanical timing reference source and calibrating the standard motion timing, specifically including: S121. The release process of the compression of the elastic overtravel component is set as a mechanical timing reference source independent of the microswitch electrical signal. This mechanical timing reference source does not depend on the on / off state of the microswitch contacts, but directly reflects the physical relative displacement change between the trigger rod and the driven seat. Its state change is driven by pure mechanical motion and has no causal relationship with the electrical contact state of the microswitch. The relative displacement detection unit adopts a combination structure of magnet and Hall element. The magnet is fixed to the trigger rod, and the Hall element is fixed to the driven seat. The Hall element outputs an analog voltage signal proportional to the magnetic field strength, which is converted into a digital quantity by an analog-to-digital converter to obtain the real-time relative displacement of the release.

[0028] The threshold comparison and timing latch unit incorporates a comparator that compares the real-time relative displacement during release with a preset displacement threshold. When the trigger rod moves in the opposite direction under the action of the return spring during fuse release, and the real-time relative displacement transitions from a state above the displacement threshold to a state below the displacement threshold, the comparator output flips. This flipping moment is recorded as the mechanical timing reference trigger moment. The displacement threshold ranges from 0.1mm to 0.5mm, with a preferred value of 0.2mm to 0.3mm.

[0029] S122. After establishing the relative displacement of the closure reference and locking the adjustable initial position component, perform at least one manual closing and releasing operation of the fuse tube. During the release operation, the threshold comparison and timing latching unit continuously monitors the comparison result between the real-time relative displacement and the displacement threshold. When it is detected that the real-time relative displacement crosses the displacement threshold downwards, the current moment is recorded as the mechanical timing reference trigger moment t. δ .

[0030] Simultaneously, the microswitch edge detection circuit monitors the microswitch output level. When it detects a transition from the closed state level to the drop-out state level, it records the current moment as the microswitch state edge time t. K Calculate t during each release process. K With t δ The time difference Δt, that is, Δt equals t K Subtract t δ Repeat the closing and releasing operation three to five times, recording the time difference for each operation. Take the arithmetic mean of all recorded time differences as the standard action timing. The standard action timing ranges from 0ms to 50ms, with a preferred value of 5ms to 20ms. This value characterizes the standard delay between the mechanical timing reference source trigger and the edge of the microswitch electrical signal during normal release.

[0031] S13. Establishment of trailing edge retention verification benchmark and setting and solidification of drift monitoring thresholds, specifically including: S131. During the release test in the calibration phase, the operator manually releases the fuse tube from the closed position to the drop position, simulating a real fuse-breaking drop condition. The relative displacement detection unit continuously collects the real-time relative displacement at a preset sampling frequency, ranging from 100 to 1000 times per second, with a preferred value of 500 times per second. The collected real-time relative displacements are arranged in a time series, forming a curve data showing the change of real-time relative displacement over time. This curve data is stored in the controller's temporary buffer in array form, with each array element containing a timestamp and the corresponding real-time relative displacement value.

[0032] Meanwhile, the microswitch edge detection circuit continuously monitors the microswitch output level. When a valid transition from the closed state to the drop-out state is detected, the current moment of the transition is recorded as the state edge moment, and this moment is timestamped and aligned with the curve data. The curve data and the state edge moment maintain a unified time reference through a high-precision timer inside the controller. The timer accuracy is no less than 1ms, ensuring that the positioning error of the state edge moment in the curve data does not exceed two sampling periods.

[0033] S132. Starting from the state edge moment, locate the array index position corresponding to that moment in the curve data. Traverse the curve data backward from that index position, sequentially reading the real-time relative displacement values ​​after the state edge moment, and comparing them one by one with the displacement threshold. When the continuously read real-time relative displacement values ​​are all lower than the displacement threshold, record the start and end times of this continuous interval, and calculate the time length between the end time and the start time. This time length is the duration. The duration ranges from 10ms to 200ms, with a preferred value of 50ms to 100ms. Record the calculated duration as the trailing edge holding verification benchmark. This benchmark characterizes the duration of sustained release of the elastic overstroke compression after the microswitch state edge occurs during the actual release of the fuse tube. The trailing edge holding verification benchmark is stored in non-volatile memory and serves as the comparison basis for subsequent trailing edge consistency diagnosis. The benchmark value remains unchanged throughout the equipment's lifecycle and is only updated when recalibrating. If there are no consecutive real-time relative displacement sampling values ​​below the displacement threshold after the state edge moment, the duration of the duration is recorded as zero, the calibration fails, and the calibration operation needs to be performed again.

[0034] S133. During the period when the fuse tube is stably in the closed state, that is, when the microswitch output stably maintains the closed level and the fuse tube is not disturbed by external forces, the controller continuously collects the closed steady-state relative displacement sampling value through the relative displacement detection unit according to a preset sampling period. The sampling period ranges from 1 min to 60 min, with a preferred value of 5 min to 15 min; the number of continuously collected sampling values ​​is not less than 10, with a preferred number of 20 to 30.

[0035] The collected closed steady-state relative displacement samples are subtracted one by one from the closed reference relative displacement to obtain the deviation of each sample relative to the closed reference relative displacement. The maximum positive deviation is selected as the maximum positive deviation, and the maximum negative deviation is selected as the maximum negative deviation. A second allowable deviation value is set based on the maximum positive deviation, which is equal to the maximum positive deviation multiplied by the position offset coefficient. The position offset coefficient ranges from 1.2 to 2.0, with a preferred value of 1.5. This coefficient is greater than 1.2 to tolerate slow displacement caused by thermal expansion and contraction, and not greater than 2.0 to avoid missed detection of loose installation. A first allowable deviation value is set based on the maximum negative deviation, which is equal to the maximum negative deviation multiplied by the preload loss coefficient. The preload loss coefficient ranges from 1.5 to 3.0, with a preferred value of 2.0. This coefficient is greater than the position offset coefficient to distinguish between normal mechanical tolerances and actual preload loss, and not greater than 3.0 to ensure sensitivity to slight preload relaxation.

[0036] S134. All key parameters determined during the calibration phase are stored in a non-volatile memory, which may be an electrically erasable programmable read-only memory or flash memory. The stored parameters include displacement threshold, standard action timing, trailing edge hold verification benchmark, microswitch closed state benchmark value, microswitch drop state benchmark value, relative displacement of the closed benchmark, first allowable deviation value, second allowable deviation value, preset allowable range, and preset timeout duration. The preset allowable range is defined as the absolute value of the deviation not exceeding 20% ​​to 50% of the standard action timing, preferably not exceeding 30%; the preset timeout duration ranges from 100ms to 500ms, with a preferred value of 200ms.

[0037] The saving operation employs a dual-backup mechanism, writing the same set of parameters to two independent sectors of non-volatile memory, and appending a cyclic redundancy check (CRC) code to the end of each sector. After writing is complete, a readback verification is performed to compare the readback data with the written data. If they do not match, the data is rewritten until the verification passes. After all parameters are saved, an installation completion flag is set; a flag value of 1 indicates that the calibration data has been solidified.

[0038] Example 3 Preferably, in Embodiment 1, step S2 is specifically implemented through the following steps: S21. Periodic acquisition and benchmark comparison of relative displacement during the closure duration, specifically including: S211. During the continuous period when the fuse tube is in the closed state, the controller enters a low-power sleep mode. The threshold comparison and timing latch unit operates independently of the controller, continuously monitoring the relationship between the real-time relative displacement and the displacement threshold. The controller wakes up from the low-power state at a preset period, with the preset period ranging from 5 to 60 minutes, preferably 15 to 30 minutes. After waking up, the controller acquires the currently monitored relative displacement through the relative displacement detection unit. After acquisition, the controller re-enters the low-power state. The acquisition method of the currently monitored relative displacement is consistent with the acquisition method of the closed reference relative displacement, both using a combination of magnet and Hall element to output a digital quantity after analog-to-digital conversion.

[0039] S212. Subtract the acquired current monitored relative displacement from the closed reference relative displacement stored in the non-volatile memory. The result is the deviation of the current monitored relative displacement from the closed reference relative displacement. If the deviation is positive, it indicates that the current monitored relative displacement is higher than the closed reference relative displacement, and the deviation direction is determined to be positive. If the deviation is negative, it indicates that the current monitored relative displacement is lower than the closed reference relative displacement, and the deviation direction is determined to be negative. The absolute value of the deviation is used for subsequent comparison with the first or second allowable deviation value to identify preload loss type drift or position offset type drift.

[0040] S22. Installation failure warning generation and drop judgment are paused, specifically including: S221. The controller compares the deviation calculated in S212 with the first and second allowable deviation values. If the deviation is negative and its absolute value is greater than the first allowable deviation value, it is determined that the preload between the trigger rod and the molten tube is lost due to mechanical loosening or wear of the contact head, identified as preload loss type drift, and a first type of installation failure warning is generated. If the deviation is positive and its value is greater than the second allowable deviation value, it is determined that the trigger rod is offset towards the molten tube due to bracket deformation or thermal expansion and contraction, identified as position offset type drift, and a second type of installation failure warning is generated. When the warning is generated, the controller writes the warning type code into the status register and triggers the communication unit to enter the standby state.

[0041] S222. Upon the generation of a Type I or Type II installation failure warning, the controller immediately sets a failure lock flag, with a value of 1 indicating a valid lock. In the locked state, the controller stops performing subsequent drop position determination and anomaly diagnosis based on dual-source timing cross-validation. Even if a wake-up signal is generated by the threshold comparison and timing latch unit, the controller only reads and records the timing information and does not perform timing cross-validation or subsequent diagnostic steps. The controller packages the failure warning type code, the current monitored relative displacement value, and the closed reference relative displacement value into failure event data according to a preset message format and sends it to the maintenance platform via the APN cellular communication interface first. If no confirmation response is received, the LoRa communication interface is switched. Before re-performing the calibration operation, the controller remains in this stopped state, and the failure lock flag remains at 1 until calibration is completed and the flag is cleared.

[0042] Example 4 Preferably, in Embodiment 1, step S3 is implemented through the following steps: S31. Mechanical timing reference trigger moment capture and first wake-up signal generation, specifically including: S311. During the release of the fusible tube, the relative displacement detection unit continuously collects the real-time relative displacement at a preset sampling frequency. The structure and working principle of the relative displacement detection unit are the same as in Example 2, and will not be repeated here. The collected real-time relative displacement value is sent to the threshold comparison and timing latch unit in real time through the data bus. The data bus width is 12 to 16 bits, and the transmission rate is not less than 10 kilobits per second, ensuring that the update delay of the real-time relative displacement value does not exceed two sampling cycles.

[0043] S312. The threshold comparison and timing latch unit has a built-in digital comparator that compares the received real-time relative displacement value with a preset displacement threshold point by point. The range and preferred value of the displacement threshold are the same as in Example 2. The comparator continuously monitors the state changes of the real-time relative displacement value. When it detects that the real-time relative displacement value changes from a state higher than the displacement threshold to a state lower than the displacement threshold, i.e., a downward crossing occurs, the comparator outputs a flip signal. This flip signal triggers a high-precision timer inside the unit. The timer has an accuracy of 1ms and records the current reading of the timer as the mechanical timing reference trigger time. This time is temporarily stored in the comparator output latch in the form of a timestamp, representing the precise time point when the compression of the elastic overstroke component is released to below the displacement threshold.

[0044] S313. The threshold comparison and timing latch unit, while recording the mechanical timing reference trigger time, triggers the first wake-up signal generation circuit by outputting a toggle signal from the comparator. The first wake-up signal is a level transition signal, and its high-level duration ranges from 10ms to 100ms, with a preferred value of 50ms. This signal is transmitted to the controller through a dedicated wake-up pin, causing the controller, which is in a low-power sleep state, to exit sleep mode. The mechanical timing reference trigger time is written into the register inside the threshold comparison and timing latch unit. The register adopts a power-down retained static random access memory or latch structure. The mechanical timing reference trigger time in the register is retained until the controller is woken up by the first wake-up signal and reads it through the data bus. After reading, the register is automatically cleared or reset by the controller sending a clear command, preparing for the next trigger.

[0045] S32. Electrical signal edge timing capture and dual-source timing information extraction, specifically including: S321. The edge detection circuit of the micro switch continuously monitors the output level of the micro switch. This edge detection circuit consists of a Schmitt trigger and a digital filter. The Schmitt trigger shapes the analog contact level of the micro switch into a digital logic level, and the digital filter filters out narrow pulses caused by contact bounce. The debouncing time of the digital filter ranges from 1ms to 10ms, with a preferred value of 5ms. When the output level transitions from a closed state to a dropped state, and the duration of the stable dropped state level after the transition is greater than the debouncing time, the edge detection circuit determines that the transition is a valid state edge. At this time, the edge detection circuit triggers an internal high-precision timer and records the current timer reading as the electrical signal edge moment. Simultaneously, the edge detection circuit generates a second wake-up signal, which is a level transition signal with a high-level duration ranging from 10ms to 100ms, with a preferred value of 50ms. The electrical signal edge is written into the register of the threshold comparison and timing latch unit. The register adopts a power-down retention storage structure to ensure that the data is not lost before the controller is woken up.

[0046] S322. The threshold comparison and timing latch unit reads the latched mechanical timing reference trigger time and electrical signal edge time from the register, respectively. Both times are represented as high-precision timer readings with a timer accuracy of 1ms. The internal sequence determination circuit performs a subtraction operation on the values ​​of the two times. If the value of the mechanical timing reference trigger time is less than or equal to the value of the electrical signal edge time, the sequence is determined to be that the mechanical timing reference trigger time is no later than the electrical signal edge time; otherwise, the electrical signal edge time is determined to have occurred before the mechanical timing reference trigger time. The sequence determination result is encoded in the form of a 1-bit binary flag. A flag value of 0 indicates that the mechanical timing reference trigger time is no later than the electrical signal edge time, and a flag value of 1 indicates that the electrical signal edge time occurred before the mechanical timing reference trigger time. This flag bit, along with the original timestamp data of the two times, is latched together in the designated address space of the register. The total capacity of the register is not less than 32 bytes, ensuring the complete preservation of dual-source timing information.

[0047] S323. After being woken up by either the first or second wake-up signal, the controller switches from low-power sleep mode to full-speed operation mode. The switching time ranges from 10μs to 100μs, with a preferred value of 50μs. The controller accesses the registers of the threshold comparison and timing latch unit via the data bus, sequentially reading the mechanical timing reference trigger time, the electrical signal edge time, and the sequence flag. After reading, the controller performs time difference calculation, subtracting the mechanical timing reference trigger time from the electrical signal edge time, and taking the absolute value of the result to obtain the time difference. The time difference calculation uses 32-bit signed integer arithmetic, with the unit being ms, and the calculation precision is consistent with the timer precision. The controller packages the mechanical timing reference trigger time, the electrical signal edge time, the sequence, and the time difference into a dual-source timing information data frame. The data frame contains 4 fields, with a total length ranging from 16 bytes to 32 bytes, with a preferred value of 20 bytes. This completes the extraction of dual-source timing information and stores it in the controller's memory for subsequent diagnostic calls.

[0048] S33. Trailing edge hold-up state extraction and timing crossover self-checking diagnosis, specifically including: S331. After being woken up by the first or second wake-up signal, the controller reads the standard action timing, trailing edge hold verification benchmark, sequence, and time difference from memory. Subsequently, the controller acquires trailing edge hold relative displacement sample values ​​after the electrical signal edge moment through the relative displacement detection unit. The relative displacement detection unit continuously acquires samples at a sampling frequency of 500 times per second, with a time interval of 2ms between two adjacent trailing edge hold relative displacement sample values. The controller compares each of the acquired preset number of trailing edge hold relative displacement sample values ​​with a displacement threshold, the displacement threshold ranging from 0.1mm to 0.5mm, with a preferred value of 0.2mm.

[0049] If a preset number of trailing edge hold relative displacement samples are all below the displacement threshold, the trailing edge hold state is marked as valid hold, and the time length between the time corresponding to the first trailing edge hold relative displacement sample below the displacement threshold and the time corresponding to the last trailing edge hold relative displacement sample below the displacement threshold is calculated. This time length is the duration of the hold period. The preset number ranges from 3 to 10, with a preferred value of 5. If any trailing edge hold relative displacement sample is not below the displacement threshold, the trailing edge hold state is marked as hold failure.

[0050] S332. The controller reads the time difference and standard action timing from memory and performs deviation calculation. The deviation value is equal to the absolute value of the time difference minus the standard action timing. The controller reads the preset allowable range from memory, calculates the allowable deviation threshold equal to the standard action timing multiplied by the preset allowable range, and compares the absolute value of the deviation value with the allowable deviation threshold. If the absolute value of the deviation value is not greater than the allowable deviation threshold, and the mechanical timing reference trigger time is not later than the electrical signal edge time, then the timing cross-validation is deemed successful. If the deviation value exceeds the allowable deviation threshold, or the electrical signal edge time precedes the mechanical timing reference trigger time, then the timing cross-validation is deemed unsuccessful. The timing cross-validation result is recorded in the form of a 1-bit flag, where a value of 1 indicates success and a value of 0 indicates failure.

[0051] S333. The controller reads the duration of the duration and the trailing edge retention verification benchmark from memory and compares the two values. The trailing edge retention verification benchmark ranges from 10ms to 200ms, with a preferred value of 50ms to 100ms. If the duration of the duration is not less than the trailing edge retention verification benchmark, i.e., the duration of the duration is greater than or equal to the trailing edge retention verification benchmark, the trailing edge consistency verification is deemed successful, indicating that the duration of continuous release of the compression of the elastic overtravel component after the microswitch state edge occurs meets the true release characteristics. If the duration of the duration is less than the trailing edge retention verification benchmark, the trailing edge consistency verification is deemed unsuccessful, indicating that there is abnormal rebound or external vibration interference during the release process. The determination result of the trailing edge consistency verification is recorded in the form of a 1-bit flag, with a value of 1 indicating success and a value of 0 indicating failure. The controller associates and stores the timing cross-verification determination result with the trailing edge consistency verification determination result as a basis for subsequent joint diagnosis to distinguish and confirm drop and abnormal types.

[0052] S34. Fall confirmation, anomaly classification and diagnosis, and event data generation, specifically including: S341. The controller reads the timing cross-validation result and the trailing edge consistency verification result from memory. Simultaneously, the controller reads the current output level of the microswitch and compares it sample-by-sample with the drop state reference value stored in non-volatile memory. If the timing cross-validation result and the trailing edge consistency verification result are both passed, and the microswitch output level is consistent with the drop state reference value and remains stable, then a genuine mechanical release of the fuse is determined, generating a confirmed drop event. The determination of stable microswitch output requires continuous monitoring for at least 3 sampling periods, each sampling period being 2ms, with a total monitoring duration of at least 6ms. The confirmed drop event includes an event sequence number, an event type code, and a timestamp; the event type code is set to 1.

[0053] S342. The controller first determines whether the timing cross-validation fails. If the timing cross-validation fails, the controller further reads the latching status of the mechanical timing reference trigger time and the electrical signal edge time. If the mechanical timing reference trigger time has been generated but the electrical signal edge time has not been generated within the preset timeout period, it is determined that the micro switch actuator is stuck or the driven seat transmission is obstructed, generating a switch stuck diagnosis. The preset timeout period ranges from 100ms to 500ms, with a preferred value of 200ms. If the timing cross-validation fails and the electrical signal edge time is generated before the mechanical timing reference trigger time, or both times have been generated but the time difference exceeds the preset allowable range, it is determined that the micro switch contact bounces or the wiring is abnormal, generating a contact bounce diagnosis.

[0054] S343. The controller reads the timing cross-validation result and the trailing edge consistency verification result. If the timing cross-validation result is passed but the trailing edge consistency verification result is failed, it is determined that the fuse tube has not undergone a true mechanical release, and the microswitch state edge is triggered by non-mechanical factors, generating a non-mechanical release false trigger diagnosis. Non-mechanical release false triggers include level jumps caused by electromagnetic interference, contact transient jitter caused by external vibration, or misidentification during the controller's power-on initialization process. This diagnosis indicates that there is a timing matching relationship between the electrical signal edge and the mechanical timing reference source, but the compression of the elastic overtravel component does not continuously decay according to the true release law, and the release process exhibits abnormal rebound or false trigger characteristics, which is different from a true mechanical fuse tube drop.

[0055] S344. The controller determines the corresponding diagnostic type code based on the aforementioned judgment results. Code 1 corresponds to a drop, code 2 to a switch jamming, code 3 to a contact bounce, and code 4 to a non-mechanical release false trigger. The controller associates and packages the diagnostic type code with the timing cross-validation judgment result, the trailing edge consistency diagnostic conclusion, the mechanical timing reference trigger time, the electrical signal edge time, the time difference, the duration of the duration, and the microswitch's state values ​​before and after. The packaged data generates event data containing the diagnostic type according to a preset message format. The total message length ranges from 64 bytes to 128 bytes, with a preferred value of 96 bytes. The event data is first sent to the maintenance platform via the communication link. If no confirmation response is received, it is written to non-volatile memory and retransmitted after the link is restored.

[0056] Example 5 like Figure 5 As shown, a drop-out fuse position monitoring system based on two-stage overtravel timing self-calibration is used to implement a drop-out fuse position monitoring method based on two-stage overtravel timing self-calibration. Specifically, it includes: a field monitoring terminal and a back-end operation and maintenance platform. The field monitoring terminal is installed on the fixed support side of the drop-out fuse and includes a fixing component, a sealed housing, a trigger conversion component, a micro switch, a relative displacement detection unit, a threshold comparison and timing latching unit, a controller, a temperature and humidity unit, a positioning unit, a multi-mode communication unit, and a power supply unit. The back-end operation and maintenance platform includes a data server and a GIS operation and maintenance platform.

[0057] During the installation and calibration phase, the on-site monitoring terminal enters calibration mode after power-on. The installer clamps the anti-slip clips of the fixing component onto the fuse fixing support, achieving electrical isolation through insulating pads. The adjustable initial position component is adjusted so that when the fuse tube is in the closed position, the contact head at the outer end of the trigger rod contacts the non-conductive outer surface of the fuse tube. The adjustable initial position component is further adjusted, pushing the trigger rod to move in the first direction toward the microswitch. The trigger rod, through the elastic overtravel component, pushes the driven seat to move in the same direction until the driven seat drives the microswitch to complete the state switch and abuts against the drive limit component. At this point, the microswitch outputs a closed level, and the maximum displacement of the driven seat is 1.0 mm. The adjustable initial position component is further adjusted so that the trigger rod continues to move relative to the driven seat, converting the remaining approximately 2 mm of the fuse tube's travel into the compression of the elastic overtravel component, until the transient relative displacement falls within the preset closed range of 0.5 mm to 1.2 mm. The adjustable initial position component is then locked, and this transient relative displacement is recorded as the closed reference relative displacement, with a preferred value of 0.7 mm.

[0058] During the calibration phase, at least one closing and releasing operation of the fuse tube is performed. During the release process, the relative displacement detection unit continuously acquires the real-time relative displacement at a preset sampling frequency of 1kHz. The threshold comparison and timing latching unit records the moment when the real-time relative displacement crosses the 0.3mm displacement threshold downwards as the mechanical timing reference trigger moment, and simultaneously records the moment when the microswitch reaches its state edge as the electrical signal edge moment. The statistical average of the time difference between the mechanical timing reference trigger moment and the electrical signal edge moment is calculated in multiple release tests and used as the standard action timing, with a preferred value of 20ms. Starting from the electrical signal edge moment, the duration during which the real-time relative displacement remains below the 0.3mm displacement threshold after the edge moment is extracted, and the length of this duration is recorded as the trailing edge hold verification reference, with a preferred value of 100ms. During the period when the fuse tube is stably in the closed state, 20 to 30 closed steady-state relative displacement samples are continuously collected. The maximum positive deviation and the maximum negative deviation relative to the closed reference are calculated. A second allowable deviation value of 0.15 mm is set based on the maximum positive deviation value, and a first allowable deviation value of 0.1 mm is set based on the maximum negative deviation value. The displacement threshold of 0.3 mm, the standard action timing of 20 ms, the trailing edge hold verification reference of 100 ms, the microswitch closed state reference value and the drop state reference value, the closed reference relative displacement of 0.7 mm, the first allowable deviation value of 0.1 mm, the second allowable deviation value of 0.15 mm, the preset allowable range of 30%, and the preset timeout duration of 200 ms are stored in non-volatile memory.

[0059] During the continuous monitoring phase, the controller wakes up from low-power sleep mode at a preset 1-hour cycle, collects the current monitored relative displacement, and compares it with the 0.7mm relative displacement of the closed reference. If the current monitored relative displacement is lower than the relative displacement of the closed reference and the absolute value of the deviation exceeds the first allowable deviation value of 0.1mm, it is identified as preload loss type drift, generating a first type of installation failure warning. If the current monitored relative displacement is higher than the relative displacement of the closed reference and the absolute value of the deviation exceeds the second allowable deviation value of 0.15mm, it is identified as position offset type drift, generating a second type of installation failure warning. After either type of installation failure warning is generated, the controller stops performing subsequent drop position judgment and anomaly diagnosis, packages the failure warning type, the current monitored relative displacement value, and the relative displacement of the closed reference into failure event data, and sends it to the data server via the APN cellular communication interface first, maintaining this stopped state until the recalibration operation is performed.

[0060] During the release diagnostic phase, as the fuse tube releases, the relative displacement detection unit continuously acquires the real-time relative displacement at a preset sampling frequency of 1kHz and sends it to the threshold comparison and timing latch unit. When the real-time relative displacement drops from above 0.3mm to below 0.3mm, the threshold comparison and timing latch unit records the mechanical timing reference trigger time and generates a first wake-up signal. When the microswitch output level transitions from the closed level to the drop-out state level, the electrical signal edge time is recorded and a second wake-up signal is generated. The threshold comparison and timing latch unit latches the order of the two moments in a register. After the controller is woken up, it reads the mechanical timing reference trigger time, the electrical signal edge time, the order, and calculates the time difference.

[0061] After the controller is woken up, it reads the standard action timing (20ms), the trailing edge hold verification benchmark (100ms), the sequence, and the time difference. It then collects 10 trailing edge hold relative displacement samples after the electrical signal edge moment using the relative displacement detection unit. It checks if all 10 trailing edge hold relative displacement samples are below the 0.3mm displacement threshold. If so, it is marked as valid hold, and the duration of the period during which all 10 samples are below the displacement threshold is calculated; otherwise, it is marked as hold failure. The time difference is compared with the 20ms standard action timing. The deviation is calculated as the absolute value of the time difference minus the standard action timing. The allowable deviation threshold is calculated as the standard action timing multiplied by a preset allowable range. If the deviation is not greater than the allowable deviation threshold and the mechanical timing benchmark trigger time is not later than the electrical signal edge moment, the timing cross-verification is considered successful; otherwise, it fails. The duration is compared with the 100ms trailing edge hold verification benchmark. If the duration is not less than 100ms, the trailing edge consistency verification is considered successful; otherwise, it fails.

[0062] If both timing cross-validation and trailing edge consistency validation pass, and the microswitch output stably maintains the drop state reference value, it is determined as a confirmed drop, and a confirmed drop event is generated. If timing cross-validation fails, and the mechanical timing reference trigger time has been generated but the electrical signal edge time has not been generated within the 200ms preset timeout period, it is determined as switch jamming. If timing cross-validation fails, and the electrical signal edge time is generated before the mechanical timing reference trigger time, or both times have been generated but the deviation value exceeds the allowable deviation threshold, it is determined as contact bounce. If timing cross-validation passes but trailing edge consistency validation fails, it is determined as a non-mechanical release false trigger. The diagnostic type is associated with the timing cross-validation result and the trailing edge consistency diagnostic conclusion and packaged to generate event data containing the diagnostic type.

[0063] Event data is first sent to the data server via the APN cellular communication interface. The data server returns an acknowledgment containing the device identifier and event sequence number within 5 seconds. If the controller does not receive an acknowledgment within the specified 10-second timeframe, it switches to the LoRa communication interface for forwarding via the LoRa gateway. If both links are unavailable, the event data is written to non-volatile memory and retransmitted in subsequent heartbeat cycles or after the links are restored. The data server performs deduplication based on the device identifier and event sequence number, performs location verification based on pre-bound coordinates and BeiDou and Global Positioning System positioning results that meet positioning quality conditions, updates the corresponding line, tower, and phase fuse status on the GIS operation and maintenance platform, and simultaneously generates an operation and maintenance work order to push to the inspection terminal.

[0064] Example 6 A drop-out fuse position monitoring device based on two-stage overtravel timing self-calibration is used to realize a drop-out fuse position monitoring method based on two-stage overtravel timing self-calibration. Specifically, it includes: a fixing component, a sealed housing, a trigger conversion component, a micro switch, a relative displacement detection unit, a threshold comparison and timing latching unit, a controller, a temperature and humidity unit, a positioning unit, a multi-mode communication unit, and a power supply unit.

[0065] The fixing assembly includes an anti-slip clamp and an insulating pad. The anti-slip clamp is made of stainless steel with anti-slip serrations on the surface, and the clamping thickness is adjustable from 5mm to 40mm. The insulating pad is made of silicone rubber, 3mm thick, and is located between the anti-slip clamp and the fuse fixing support. The sealing housing is connected to the fixing assembly by bolts. The housing is made of aluminum alloy with an anodized surface, achieving an IP67 protection rating. The housing has a linear guide hole inside, and the entire housing and trigger conversion assembly are located outside the fuse tube's movement path.

[0066] The trigger conversion assembly includes a trigger rod, a driven seat, an elastic overtravel element, an adjustable initial position element, a drive limit element, and a return spring. The trigger rod and driven seat are coaxially mounted within a linear guide hole in the housing. The trigger rod has a contact head at the end facing the fuse tube. The contact head is made of a wear-resistant, insulated roller with a diameter of 8mm. The roller's outer surface is covered with a polytetrafluoroethylene (PTFE) insulating layer, and the contact head contacts the non-conductive outer surface of the fuse tube. A shoulder is provided in the middle of the trigger rod. A compression spring is installed between the shoulder and the driven seat as an elastic overtravel element. The compression spring is made of stainless steel wire with a wire diameter of 0.5mm, an outer diameter of 6mm, a free length of 15mm, a stiffness coefficient of 2N / mm, and a maximum allowable compression of 5mm. The driven seat forms a pressing surface on the side facing the microswitch, with a pressing surface area of ​​25mm². 2The drive limiting component is an annular step on the inner wall of the housing, with a step height of 1.0 mm. Taking a microswitch with a permissible safe displacement of 1.2 mm as an example, the position of the drive limiting component is set so that the maximum displacement of the driven seat towards the microswitch is 1.0 mm. This maximum displacement is not less than the 0.8 mm actuation displacement required for the microswitch to move from the free position to the reliable switching position, and not greater than the 1.2 mm permissible safe displacement of the microswitch. The adjustable initial position component is a threaded adjusting sleeve with a locking nut, with an adjustment stroke of 5 mm and a thread pitch of 0.5 mm. The initial position of the contact head relative to the closed fuse tube is changed by rotating the adjusting sleeve, and the adjustment is completed by fixing it with the locking nut. The return spring is a tension spring, located between the trigger rod and the housing. After the fuse tube is released, it pulls the trigger rod to return to its original position away from the microswitch. The tension of the return spring is 1 N to 3 N, preferably 2 N.

[0067] The micro switch is fixed to the inner wall of the housing, with the actuating element of the micro switch facing the pressing surface of the driven seat. The micro switch has an operating stroke of 0.8 mm, an overtravel of 0.2 mm, a total stroke of 1.2 mm, and a permissible safe displacement of 1.2 mm. When the driven seat reaches the drive limit, the micro switch has reliably switched, and its actuating element has been pressed in by 1.0 mm, which has not yet exceeded the permissible safe displacement.

[0068] The structure, working principle, and calibration method of the relative displacement detection unit are the same as in Example 2, and will not be repeated here. The relative displacement detection unit can also be replaced with a photoelectric, inductive, capacitive, or resistive displacement detection structure.

[0069] The threshold comparison and timing latch unit includes a comparator circuit and a D flip-flop latch circuit. The comparator circuit compares the relative displacement signal output by the Hall element with a preset displacement threshold, which is set to 0.3 mm. When the real-time relative displacement drops from above 0.3 mm to below 0.3 mm, the comparator output flips, generating a first wake-up signal. The microswitch edge detection circuit monitors the microswitch output level and generates a second wake-up signal when a valid edge transitioning from the closed level to the drop-out level is detected. The D flip-flop latch circuit receives the first and second wake-up signals respectively, records the order and time difference between the mechanical timing reference trigger time and the electrical signal edge time, and holds the latch result until the controller is woken up and read. The threshold comparison and timing latch unit operates continuously when the controller is in a low-power sleep state, with an operating current of less than 10 μA.

[0070] The controller employs a low-power ARM Cortex-M4 core microcontroller with a clock frequency of 48MHz, and integrates a 12-bit analog-to-digital converter, non-volatile memory, and a real-time clock. During non-event periods, the controller enters a low-power sleep state with power consumption less than 5μA. Upon waking, the controller reads the latched timing information, performs timing cross-validation, and performs trailing-edge consistency diagnostics. The non-volatile memory stores the relative displacement of the closed reference, displacement thresholds, timing verification parameters, drift monitoring thresholds, and switch state references.

[0071] The temperature and humidity unit integrates digital temperature and humidity sensors, with a temperature measurement range of -40℃ to 70℃ and a humidity measurement range of 0%RH to 100%RH, achieving measurement accuracy of ±0.5℃ for temperature and ±3%RH for humidity. The positioning unit supports dual-mode positioning using both the BeiDou Navigation Satellite System and the Global Positioning System, with a cold start time of less than 30 seconds and horizontal positioning accuracy better than 5 meters. The multi-mode communication unit includes a power APN cellular communication module and a LoRa communication module. The APN module supports 4G / 5G networks, while the LoRa module operates at 470MHz with a transmit power of 20dBm. The power supply unit includes a lithium thionyl chloride battery and a power management chip. The battery capacity is 19Ah, with a nominal voltage of 3.6V, and a designed service life of no less than 8 years under operating conditions of a 1-hour heartbeat cycle and no more than 10 events per day.

[0072] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0073] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for monitoring the position of a drop-out fuse based on a two-stage overtravel timing self-check, characterized in that, include: Adjust the adjustable initial position component so that the driven seat presses against the micro switch and abuts against the drive limit component to establish a closed reference relative displacement. The elastic overtravel component is set as a mechanical timing reference source independent of the micro switch electrical signal to calibrate the standard action timing; Establish a trailing edge retention verification benchmark and save the displacement threshold, timing verification parameters, relative displacement of the closed benchmark, and drift monitoring threshold. Collect the current relative displacement and compare it with the relative displacement of the closed reference periodically. If the drift monitoring threshold is exceeded, an installation failure warning is generated and the drop judgment is stopped. The first wake-up signal is generated when the real-time relative displacement crosses the displacement threshold, and the second wake-up signal is generated when the micro switch has an edge. The latching time sequence is stored and the controller is woken up. Extract the trailing edge hold state, perform timing cross-validation and trailing edge consistency diagnosis based on the timing verification parameters, distinguish between drop and anomaly, and generate event data containing diagnostic types.

2. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 1, characterized in that, The adjustable initial position component causes the driven seat to press against the micro switch and abut against the drive limit component, establishing a closed reference relative displacement, specifically including: The fixing component is installed on the fixing support, so that the housing and the trigger conversion component are located outside the movement path of the molten tube, so that the molten tube is in the closed position and the outer end of the trigger rod is in contact with the molten tube, thereby obtaining the initial relative displacement between the trigger rod and the driven seat. Adjust the adjustable initial position component to push the trigger rod to move in the first direction toward the micro switch. The trigger rod pushes the driven seat to move in the same direction through the elastic overtravel component until the driven seat drives the micro switch to complete the state switching and abuts against the drive limit component. After the driven seat is blocked, the adjustable initial position member continues to be adjusted along the first direction, so that the trigger rod continues to move relative to the driven seat and converts the remaining stroke of the fuse tube into the compression amount of the elastic overstroke member, until the adjustment transient relative displacement falls into the preset closed range, the adjustable initial position member is locked, and the locked adjustment transient relative displacement is recorded as the closed reference relative displacement.

3. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 2, characterized in that, The step of setting the elastic overtravel component as a mechanical timing reference source independent of the microswitch electrical signal to calibrate the standard action timing specifically includes: The release of the compression amount of the elastic overtravel component is set as a mechanical timing reference source independent of the micro switch electrical signal. The state of the mechanical timing reference source is continuously monitored and obtained by the relative displacement detection unit, and its trigger time is defined as the moment when the real-time relative displacement of the release crosses the displacement threshold downward. After establishing the relative displacement of the closed reference, perform at least one closing and releasing operation of the fuse tube, record the time difference between the triggering time of the mechanical timing reference source and the state edge time of the micro switch during each release process, and take the statistical average of the time differences recorded multiple times as the standard action timing.

4. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 3, characterized in that, The establishment of the trailing edge retention verification benchmark and the saving of displacement thresholds, timing verification parameters, relative displacement of the closed benchmark, and drift monitoring thresholds specifically include: During the release test in the calibration phase, the relative displacement detection unit continuously collects the curve data of the real-time relative displacement change over time, and records the moment when the micro switch reaches the state edge. Starting from the state edge moment, extract the duration of the real-time relative displacement curve data after the state edge moment that remains below the displacement threshold, and record the length of the duration of the duration as the verification benchmark for the trailing edge. During the period when the fusible tube is stably in a closed state, multiple closed steady-state relative displacement sampling values ​​are continuously collected by the relative displacement detection unit. The maximum positive deviation and the maximum negative deviation of the multiple closed steady-state relative displacement sampling values ​​relative to the closed reference displacement are calculated. A second allowable deviation value is set according to the maximum positive deviation value, and a first allowable deviation value is set according to the maximum negative deviation value. The displacement threshold, relative displacement of the closure reference, timing verification parameters, and drift monitoring threshold are stored in a non-volatile memory. The timing verification parameters include standard action timing, trailing edge hold verification reference, microswitch closure state reference value and drop state reference value, preset allowable range, and preset timeout duration. The drift monitoring threshold includes a first allowable deviation value and a second allowable deviation value.

5. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 1, characterized in that, The process of collecting the current monitored relative displacement and comparing it with the relative displacement of the closed reference point on a periodic basis specifically includes: During the period when the fusible tube is in a closed state, the controller wakes up and collects the current relative displacement at a preset cycle; The current monitored relative displacement is compared with the relative displacement of the closed reference, and the deviation amount and direction of the current monitored relative displacement relative to the relative displacement of the closed reference are calculated.

6. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 5, characterized in that, If the drift monitoring threshold is exceeded, an installation failure warning is generated and the drop test is stopped, specifically including: If the current monitored relative displacement is lower than the closed reference relative displacement and the absolute value of the deviation exceeds the first allowable deviation value, it is identified as preload loss type drift and a first type of installation failure warning is generated; if the current monitored relative displacement is higher than the closed reference relative displacement and the absolute value of the deviation exceeds the second allowable deviation value, it is identified as position offset type drift and a second type of installation failure warning is generated. After the first type of installation failure warning or the second type of installation failure warning is generated, the controller stops performing subsequent drop position judgment and anomaly diagnosis, packages the failure warning type, the current monitored relative displacement value and the relative displacement of the closed reference as failure event data and reports it to the operation and maintenance platform through the communication link, and maintains this stopped state until the calibration operation is re-executed.

7. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 4, characterized in that, The generation of a first wake-up signal when the real-time relative displacement crosses a displacement threshold specifically includes: During the release of the fuse tube, the relative displacement detection unit continuously collects the real-time relative displacement of the release at a preset sampling frequency, and sends the real-time relative displacement value of the release to the threshold comparison and timing latching unit. The threshold comparison and timing latch unit compares the released real-time relative displacement value with a preset displacement threshold. When it is detected that the released real-time relative displacement value has crossed from a state higher than the displacement threshold to a state lower than the displacement threshold, the current moment is recorded as the mechanical timing reference trigger moment. The threshold comparison and timing latch unit generates a first wake-up signal while recording the mechanical timing reference trigger time, and latches the mechanical timing reference trigger time into the register of the threshold comparison and timing latch unit, and holds it until the controller is woken up and reads it.

8. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 7, characterized in that, When the microswitch generates an edge, it produces a second wake-up signal, latches the timing sequence, and wakes up the controller, specifically including: The edge detection circuit of the micro switch continuously monitors the output level state of the micro switch, identifies the edge of the output level state transitioning from the closed level to the dropped level, and when a valid state edge is identified, records the current time as the electrical signal edge time, generates a second wake-up signal, and latches the electrical signal edge time in the register of the threshold comparison and timing latch unit. The threshold comparison and timing latch unit latches the order of the mechanical timing reference trigger time and the electrical signal edge time in the register; After the controller is awakened by the first wake-up signal or the second wake-up signal, it reads the latched mechanical timing reference trigger time, electrical signal edge time and their order, and calculates the time difference between the two to complete the extraction of dual-source timing information.

9. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking as described in claim 8, characterized in that, The extraction of trailing edge hold state, based on the timing verification parameters, involves performing timing cross-validation and trailing edge consistency diagnosis, specifically including: After the controller is woken up, it reads the standard action timing, trailing edge hold verification benchmark, sequence and time difference, and collects a preset number of trailing edge hold relative displacement sampling values ​​after the edge of the electrical signal through the relative displacement detection unit. It then determines whether the preset number of trailing edge hold relative displacement sampling values ​​are all lower than the displacement threshold. If so, the trailing edge hold state is marked as valid hold, and the length of the duration during which the preset number of trailing edge hold relative displacement sampling values ​​are all lower than the displacement threshold is calculated. Otherwise, it is marked as hold failure. The time difference is compared with the standard action sequence. If the deviation between the time difference and the standard action sequence is within the preset allowable range and the order is that the mechanical timing reference trigger time is not later than the electrical signal edge time, the timing cross-verification is determined to be successful; otherwise, the timing cross-verification is determined to be unsuccessful. The duration of the duration is compared with the trailing edge retention verification benchmark. If the duration of the duration is not less than the trailing edge retention verification benchmark, the trailing edge consistency verification is deemed to have passed; otherwise, the trailing edge consistency verification is deemed to have failed.

10. The method for monitoring the position of a drop-out fuse based on two-stage overtravel timing self-checking according to claim 9, characterized in that, The process of distinguishing between falls and anomalies and generating event data containing diagnostic types specifically includes: The controller obtains the determination results of timing cross-validation and trailing edge consistency verification. If both timing cross-validation and trailing edge consistency verification pass, and the micro switch output stably maintains the drop state reference value, then it is determined as a confirmed drop and a confirmed drop event is generated. If the timing cross-verification fails, and the mechanical timing reference trigger time has been generated but the electrical signal edge time has not been generated within the preset timeout period, it is determined that the switch is stuck; if the timing cross-verification fails, and the electrical signal edge time is generated before the mechanical timing reference trigger time, or both times have been generated but the time difference exceeds the preset allowable range, it is determined that the contact bounces. If the timing cross-validation passes but the subsequent edge consistency validation fails, it is determined to be a non-mechanical release false trigger. The diagnostic type corresponding to the judgment result is associated and packaged with the time-series cross-validation judgment result and the consistency diagnosis conclusion of the trailing edge to generate event data containing the diagnostic type.

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