Remote control method of far jump protection soft pressure plate in single side maintenance working condition of power transmission line

Abstract

The application provides a remote jump protection soft pressure plate remote control method for single side maintenance working condition of a power transmission line, which comprises the following steps: issuing a corresponding remote control preset command to a protection device of a target soft pressure plate, and identifying return information returned by the protection device; the target soft pressure plate at least comprises a remote jump sending soft pressure plate and a remote jump receiving soft pressure plate; the return information at least comprises return correction or negative confirmation or timeout without receiving return correction messages; when the return information is return correction, a remote control execution command is issued; the remote control execution command is used for setting an actual value of a soft pressure plate state of the protection device to exit, and sending a state change message as an execution result after the exit action is executed; after receiving the execution result, a corresponding remote control result is output according to the content of the execution result, wherein the remote control result at least comprises success or exception. The application realizes closed loop management and control of automatic exit in maintenance and automatic recovery in operation, and completely solves the reverse safety hidden danger of missing protection after maintenance.

Description

Technical Field

[0001] This invention relates to the field of power system automation technology, and in particular to a remote control method for a remote tripping protection soft pressure plate in the single-sided maintenance condition of a transmission line. Background Technology

[0002] The soft control panels related to remote trip protection include remote trip transmitting soft control panels and remote trip receiving soft control panels (corresponding to GOOSE transmitting soft control panels and GOOSE receiving soft control panels in IEC 61850 smart substations). Their functions are as follows: The remote trip transmitting soft control panel controls whether the local protection device sends a remote trip signal. When activated, it allows the transmission of remote trip messages, and when deactivated, it prohibits the transmission of any remote trip messages. The remote trip receiving soft control panel controls whether the local protection device responds to and processes the received remote trip commands. When activated, it allows the reception and processing of remote trip commands, and when deactivated, it ignores all received remote trip commands.

[0003] When both pressure plates retract simultaneously, the remote trip signal achieves a dual-path blockade within the protection device, meaning it cannot be sent out or received. Regardless of the cause (mis-triggered during maintenance, device malfunction, external interference, etc.), the remote trip signal cannot be sent out to the protection device on this side, and the equipment on the other side will not receive any remote trip command.

[0004] The regulations clearly require that when a line is out of service and the corresponding switch on either side of the line needs to be restored to operation, the remote tripping of the line should be deactivated. Manually disengaging the remote tripping soft switch is currently the primary means of achieving this requirement.

[0005] The shortcomings of the existing soft pressure plate operation method: Currently, the throwing and retraction operation of the long jump soft pressure plate relies entirely on manual execution, which has the following shortcomings: (i) High risk of missed shutdown. The activation and deactivation of remote tripping control plates rely on the operator's memory or operation ticket. Due to the complexity of maintenance procedures, fatigue from nighttime work, and interference from cross-operations, the problem of missed or forgotten shutdown is very likely to occur. The direct cause of the aforementioned 220kV bus differential protection transmission accident was that the maintenance personnel failed to deactivate the remote tripping control plate of the line protection.

[0006] (ii) Recovery relies on manual intervention. If the remote tripping pressure plate is not put into operation after maintenance, the protection function will be lost for a long time, creating a reverse safety hazard.

[0007] (iii) Lack of anti-misoperation interlock. The soft pressure plate activation / deactivation interface is usually open to all operators, posing a risk of others accidentally activating it during maintenance.

[0008] (iv) Lack of an automated synchronous exit mechanism. In the current operation, the exit of the sending and receiving pressure plates is done manually, which poses a risk of one-sided omissions such as "exiting the sending plate but not the receiving plate" or "exiting the receiving plate but not the sending plate". Summary of the Invention

[0009] The purpose of this invention is to propose a remote control method for the soft pressure plate of the remote trip protection in the single-sided maintenance condition of transmission lines, which solves the technical problem of how to realize intelligent closed-loop control of automatic exit from maintenance and automatic recovery of operation, and completely solves the reverse safety hazard of missed protection after maintenance.

[0010] On the one hand, a remote control method for the soft pressure plate of the remote trip protection in the single-sided maintenance condition of a transmission line is provided, including: Send a corresponding remote preset command to the protection device of the target soft pressure plate, and identify the return information returned by the protection device; wherein, the target soft pressure plate includes at least a remote jump sending soft pressure plate and a remote jump receiving soft pressure plate; the return information includes at least a correct or negative confirmation of return calibration or a timeout message not received. When the returned information indicates that the return to calibration is correct, a remote execution command is issued; wherein, the remote execution command is for the protection device to set the actual value of the soft pressure plate status to exit, and after the exit action is completed, to send a status change message as the execution result. Upon receiving the execution result, the corresponding remote control result is output based on the content of the execution result, wherein the remote control result includes at least success or error.

[0011] Preferably, the method further includes terminating the remote control operation and outputting an alarm message when the returned information is a negative confirmation or when no return-to-school message is received after a timeout.

[0012] Preferably, the remote control preset command is to simultaneously send an exit action command to the remote jump soft pressure plate and the remote jump receiving soft pressure plate within a preset logical scan cycle.

[0013] Preferably, it further includes, after the protection device receives a remote preset command, verifying the legality of the remote preset command according to preset verification items; If the verification passes, a confirmation message indicating that the return to the correct location is returned as the return information; if the verification fails, a negative confirmation message is returned as the return information. The verification items include at least whether the user has operating permissions, whether the interlocking conditions are met, whether the object exists, and whether the object can be remotely controlled.

[0014] Preferably, the step of outputting the corresponding remote control result based on the content of the execution result includes: If all target soft pressure plates are successfully remotely controlled, the remote control result will be output as successful. If any target soft pressure plate remote control fails, an alarm pop-up will be displayed and subsequent operations will be paused, and a complete error log will be recorded.

[0015] Preferably, it further includes, after identifying a valid line maintenance sign, if identified, simultaneously implementing access control for the operation entry; wherein, implementing access control for the operation entry includes at least the following: the remote control button for sending / receiving soft pressure plate on the human-machine interface is automatically grayed out and cannot be clicked; the operator's remote control interface for sending / receiving soft pressure plate rejects any operation requests; When an operator attempts to engage a locked remote jump soft pressure plate, the system displays a corresponding locking prompt. If it is necessary to forcibly engage the remote jump plate during maintenance, a user with the corresponding permissions needs to enter an advanced authorization code to temporarily unlock the self-lock. Setting the temporary unlock triggers a network-wide audible and visual alarm and records it to the security audit log. If the line maintenance validity flag still exists after the self-locking is released, the system will automatically lock again after the preset safe time threshold is reached.

[0016] Preferably, it also includes, after the line maintenance valid indicator is cleared to zero, releasing the ash lock of the remote control button of the remote trip pressure plate and restoring normal remote control operation permission; Send a remote preset command to the protection device, and after receiving the correct confirmation of the return calibration of the two pressure plates, send a remote execution command. After the device completes the execution, send a status change message. The system compares the status of the pressure plate sent by the protection device with the instructions issued by the background. If they are all consistent, it outputs a recovery reminder message and generates a confirmation record of successful maintenance. If the command to engage fails, it immediately issues an alarm.

[0017] Preferably, it also includes recording the preset command response timeout, the command execution response timeout, and the status change message waiting timeout, respectively; If any of the timings reaches the corresponding preset threshold time for the first time, then retry once; If the retry fails, an alarm message will be output and the operation will be terminated; during the retry execution, the maintenance status flag will not be switched.

[0018] In summary, implementing the embodiments of the present invention has the following beneficial effects: The remote control method for remote tripping protection soft pressure plates in single-sided maintenance conditions of transmission lines provided by this invention breaks through the traditional "manual judgment + manual operation" mode. By binding the activation and deactivation operations of the soft pressure plates with the automatic determination results of the line maintenance status, it achieves fully automatic, zero-delay, and zero-intervention activation and deactivation of the remote tripping soft pressure plates. When the system determines that the line is under maintenance, it automatically triggers the remote control deactivation process of the soft pressure plates; when the maintenance is completed and the line returns to normal operation, it automatically triggers the remote control activation and reactivation process of the soft pressure plates. The entire process requires no manual judgment or operation. Unlike traditional manual operations that may suffer from one-sided omissions, this method achieves synchronous, linked, and forced remote control exit of the remote tripping transmitting and receiving soft pressure plates: After determining the maintenance status, the system simultaneously issues two remote control preset commands, synchronously setting both the transmitting and receiving soft pressure plates to 0 and exiting. If either remote control fails (preset failure, execution failure, timeout, or calibration rejection), the system immediately stops subsequent operations and issues an alarm, ensuring that maintenance work only begins after both paths have exited simultaneously. The exit status is confirmed by both the protection device calibration and the status change message, and the background updates the display synchronously, achieving visualized closed-loop management of the operation. The engineering value of simultaneous dual-path exit lies in: the transmitting end blocks the transmission of remote tripping signals, and the receiving end prevents the remote tripping signal from the other side from accidentally triggering the local side, achieving complete isolation of the remote tripping function. During the maintenance period, the system automatically locks the access permission for the remote tripping soft pressure plates, and any operator workstation operation to access these two pressure plates is rejected, preventing personnel from accidentally accessing the pressure plates during maintenance. After maintenance is completed, the system automatically unlocks the permissions and remotely activates the remote trip soft pressure plate, realizing intelligent closed-loop control of "automatic exit from maintenance and automatic resumption of operation", which completely solves the reverse safety hazard of missed protection after maintenance. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0020] Figure 1 This is a schematic diagram of the main flow of a remote control method for a soft pressure plate of a transmission line under single-sided maintenance conditions, according to an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] like Figure 1The diagram shown is a schematic representation of an embodiment of a remote tripping protection soft pressure plate remote control method for single-sided maintenance of transmission lines provided by the present invention. In this embodiment, the method includes the following steps: Step S1: Send the corresponding remote preset command to the protection device of the target soft pressure plate and identify the return information returned by the protection device; wherein, the target soft pressure plate includes at least a remote jump sending soft pressure plate and a remote jump receiving soft pressure plate; the return information includes at least a correct or negative confirmation of return calibration or a timeout message not received. Step S2: When the returned information indicates that the calibration is correct, a remote execution command is issued; wherein, the remote execution command is for the protection device to set the actual value of the soft pressure plate status to exit, and after the exit action is completed, to send a status change message as the execution result. Step S3: After receiving the execution result, output the corresponding remote control result according to the content of the execution result, wherein the remote control result includes at least success or error.

[0023] It should be noted that, in the embodiments of the present invention, the technical basis for the remote control of the soft pressure plate is that both the remote-jumping soft pressure plate and the remote-jumping receiving soft pressure plate are defined as remotely writable in the communication data model of the protection device, supporting remote modification. Devices from different manufacturers differ only in the naming of data objects, but their functions are essentially the same.

[0024] The remote deployment and retraction of the soft pressure plate falls under the category of remote control (not remote adjustment / setup modification). Remote control operation must follow the complete safety procedure of "preset (selection) → return to calibration confirmation → execution → execution confirmation", as shown in the table below:

[0025] Among these, "return-to-calibration confirmation" is a crucial safety step in remote operation—the device verifies the legality of preset commands in terms of permissions, interlocks, and status, and then returns the verification result to the master station. The master station only issues remote execution commands after receiving a "return-to-calibration correct" confirmation; if a negative confirmation is received or a return-to-calibration message is not received within a timeout period, the operation is terminated and an alarm is triggered. Supported communication protocols include: IEC 61850 MMS protocol (smart substations): implemented through Select and Operate services; IEC 60870-5-103 / 104 protocol (conventional substations): implemented through remote command.

[0026] One embodiment further includes terminating the remote control operation and outputting an alarm message when the returned information is a negative acknowledgment or no return-to-school message is received after a timeout.

[0027] In one embodiment, the remote preset command is to simultaneously issue an exit action command to both the remote tripping soft pressure plate and the remote tripping receiving soft pressure plate within a preset logical scan cycle. When the line maintenance validity flag changes from 0 to 1, the system automatically executes the following process: The monitoring backend simultaneously sends two remote preset commands (selection commands) to the line protection device via the remote control protocol: Target object 1: [Remote tripping soft pressure plate], target value = 0 (exit); Target object 2: [Remote tripping receiving soft pressure plate], target value = 0 (exit); The two commands are issued within the same logical scan cycle to ensure the synchronization of the exit action.

[0028] In one embodiment, when the protection device receives a remote preset command, it verifies the legality of the remote preset command according to preset verification items; if the verification passes, it returns a confirmation message confirming the correctness of the verification as the return information; if the verification fails, it returns a confirmation message confirming the negative verification as the return information; wherein, the verification items include at least whether the user has operating authority, whether the interlocking conditions are met, whether the object exists, and whether the object can be remotely controlled.

[0029] The protection device verifies the validity of the two preset commands (including operating permissions, interlocking conditions, object existence, and remote control capability). Upon successful verification, it returns a "correct calibration" confirmation message to the monitoring backend; if verification fails, it returns a negative confirmation. After receiving the "correct calibration" confirmation for both commands, the backend issues a remote control execution command. Upon receiving the execution command, the device sets the actual status of the two soft pressure plates to 0. After execution, the device sends a status change message as final confirmation of the execution result.

[0030] In one embodiment, the step of outputting the corresponding remote control result based on the execution result includes: if all target soft pressure plates are successfully remote controlled, then the remote control result is output as successful; if any target soft pressure plate fails to be remote controlled, then an alarm pop-up is output and subsequent operations are paused, and a complete error log is recorded.

[0031] If any remote control of a pressure plate fails (preset failure, execution failure, timeout, or negative confirmation return), the system will immediately: display an alarm pop-up window "Automatic exit failure of remote pressure plate inspection: [failed pressure plate name], please intervene manually"; suspend subsequent operations; and record a complete error log (including the failure reason code).

[0032] The background database updates the pressure plate status, and the HMI synchronously displays the "Exit" status. The device panel also displays the updated status locally. An operation log is generated throughout the process, including: operation time (accurate to milliseconds), operation source (automatic system operation), names of the two pressure plates, status before operation, status after operation, return-to-calibration confirmation result, and operation result (success / failure).

[0033] One embodiment further includes: after identifying a valid line maintenance indicator, if identified, simultaneously locking the operation entry point; wherein, the operation entry point locking includes at least the following: the remote control button for sending / receiving soft pressure plates on the human-machine interface is automatically grayed out and cannot be clicked; the operator's remote control interface for sending / receiving soft pressure plates rejects any operation requests; when the operator attempts to operate on the locked soft pressure plate, the system displays a corresponding locking prompt; if it is necessary to forcibly operate the soft pressure plate during maintenance, a user with the corresponding permissions needs to enter an advanced authorization code to temporarily unlock the self-lock, wherein temporarily unlocking the self-lock triggers a network-wide audible and visual alarm and records it to the security audit log; when the self-lock is unlocked, if the valid line maintenance indicator still exists, it will automatically relock after a preset safety time threshold is reached.

[0034] To prevent accidental restoration of operation permissions, the system automatically locks the access permissions. When the line maintenance validity flag is 1, in addition to automatically exiting the soft-close mechanism, the system also blocks access to the following operation entries: The remote control button for sending / receiving soft pressure plate on the human-machine interface of the background monitoring system is automatically grayed out and cannot be clicked.

[0035] The remote control interface for the operator workstation and engineer workstation on the remote-controlled soft pressure plate rejects any operation requests.

[0036] When the operator attempts to activate the locked remote jump soft pressure plate, the system displays a prompt box: "The equipment is under maintenance, and the remote jump pressure plate activation permission has been automatically locked." If the remote tripping switch needs to be forcibly engaged during maintenance (e.g., for emergency power restoration, special testing needs), a user with "administrator" privileges must enter an advanced authorization code to temporarily release the self-lock. This operation will trigger a network-wide audible and visual alarm and be recorded in the safety audit log. After the self-lock is released, if the line maintenance validity flag is still 1, the system will automatically relock after a set time (e.g., 3 minutes).

[0037] One embodiment further includes: when the line maintenance validity flag is cleared, releasing the gray lock of the remote control button of the remote trip pressure plate and restoring normal remote control operation permission; sending a remote control preset command to the protection device, and after receiving the correct confirmation of the return calibration of the two pressure plates, sending a remote control execution command; when the device completes the execution, sending a status change message; comparing whether the pressure plate status sent by the protection device is consistent with the command sent by the background; if they are all consistent, outputting a recovery reminder message and generating a confirmation record of successful maintenance; if the command fails to be activated, immediately issuing an alarm.

[0038] The system is configured to automatically initiate a reset process for the soft pressure plate. Once the line maintenance validity flag is cleared, the system automatically executes the following procedure: The system automatically unlocks the remote control button on the remote jump pressure plate, restoring normal remote control operation privileges.

[0039] The dual-pressure plate synchronous remote control preset command is issued, and the monitoring backend issues the remote control preset command to the protection device: Target 1: [Long-jump transmission soft pressure plate], target value = 1 (investment) Target object 2: [Long jump receiving soft pressure plate], target value = 1 (investment) Upon receiving "Return to calibration correct" confirmations from the two pressure plates, the backend issues a remote execution command. After the device completes execution, it sends a status change message.

[0040] After status verification and successful activation confirmation, the system compares the status of the pressure plate sent by the protection device with the command issued by the background system. Once all are consistent, the background system displays "Line is running normally, remote tripping function fully restored" and generates a confirmation record of "Maintenance exited, soft pressure plate successfully restored".

[0041] In case of an error, if the command to activate fails, the system will immediately issue an alarm saying "Automatic activation of remote tripping pressure plate failed, please intervene manually" to prevent the remote tripping protection function from being lost after power is restored.

[0042] One embodiment further includes recording a preset command response timeout, an execution command response timeout, and a status change message waiting timeout; if any of these timeouts reaches the corresponding preset threshold time for the first time, a retry is performed; if the retry fails, an alarm message is output and the operation is terminated; wherein, during the retry execution, the maintenance status flag is set not to switch.

[0043] The remote control timeout and retry mechanism is set in the embodiment, as shown in the table below:

[0044] Retry strategy: After the first failure, the system will automatically retry once; if the retry still fails, an alarm will be issued and the operation will be terminated; the maintenance status flag will not be switched during the retry to ensure the continuity of protection.

[0045] In specific embodiments, for protocol adaptation of devices from different manufacturers, the differences in soft pressure plate object models of devices from different manufacturers are adapted in a configurable manner, as shown in the table below.

[0046]

[0047] The system automatically matches the type of the current protection device and the corresponding soft pressure plate object model through a pre-configured device template library, and issues the correct remote control command.

[0048] In a specific embodiment, the protective effect of the soft pressure plate after withdrawal can be verified in the following ways:

[0049] This invention addresses the persistent industry problems of missed or forgotten manual removal of remote-controlled soft pressure plates during single-sided maintenance of transmission lines. It proposes a fully automated remote-controlled activation / deactivation method consisting of "status linkage triggering—synchronous remote control preset of dual pressure plates—retrofit confirmation—execution—status confirmation—authority self-locking control—automatic reset and recovery." The solution possesses the following core advantages: Completely eliminate manual leakage: upgrade from "human defense" to "technology defense", automatically complete the remote control withdrawal of soft pressure plate; Simultaneous blocking of both transmission and reception paths: Simultaneously blocking both the "transmission" and "reception" paths of the far-hop signal to achieve complete isolation; Standard remote control procedures ensure safety: Strictly follow the remote control safety protocol of "preset → return to calibration → execute → confirm" to prevent misoperation; Dual protection against accidental entry and missed entry: During maintenance, entry permissions are locked, and the system automatically resets upon completion of maintenance. Zero-risk implementation: Fully utilize the existing remote control function of the soft pressure plate of the protection device, requiring no hardware modification; Highly versatile: Compatible with the communication protocols of conventional and intelligent stations, as well as various mainstream protection device manufacturers.

[0050] In summary, implementing the embodiments of the present invention has the following beneficial effects: The remote control method for remote tripping protection soft pressure plates in single-sided maintenance conditions of transmission lines provided by this invention breaks through the traditional "manual judgment + manual operation" mode. By binding the activation and deactivation operations of the soft pressure plates with the automatic determination results of the line maintenance status, it achieves fully automatic, zero-delay, and zero-intervention activation and deactivation of the remote tripping soft pressure plates. When the system determines that the line is under maintenance, it automatically triggers the remote control deactivation process of the soft pressure plates; when the maintenance is completed and the line returns to normal operation, it automatically triggers the remote control activation and reactivation process of the soft pressure plates. The entire process requires no manual judgment or operation. Unlike traditional manual operations that may suffer from one-sided omissions, this method achieves synchronous, linked, and forced remote control exit of the remote tripping transmitting and receiving soft pressure plates: After determining the maintenance status, the system simultaneously issues two remote control preset commands, synchronously setting both the transmitting and receiving soft pressure plates to 0 and exiting. If either remote control fails (preset failure, execution failure, timeout, or calibration rejection), the system immediately stops subsequent operations and issues an alarm, ensuring that maintenance work only begins after both paths have exited simultaneously. The exit status is confirmed by both the protection device calibration and the status change message, and the background updates the display synchronously, achieving visualized closed-loop management of the operation. The engineering value of simultaneous dual-path exit lies in: the transmitting end blocks the transmission of remote tripping signals, and the receiving end prevents the remote tripping signal from the other side from accidentally triggering the local side, achieving complete isolation of the remote tripping function. During the maintenance period, the system automatically locks the access permission for the remote tripping soft pressure plates, and any operator workstation operation to access these two pressure plates is rejected, preventing personnel from accidentally accessing the pressure plates during maintenance. After maintenance is completed, the system automatically unlocks the permissions and remotely activates the remote trip soft pressure plate, realizing intelligent closed-loop control of "automatic exit from maintenance and automatic resumption of operation", which completely solves the reverse safety hazard of missed protection after maintenance.

[0051] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A remote control method for a soft pressure plate of a transmission line tripping protection system during single-sided maintenance, characterized in that, include: Send a corresponding remote preset command to the protection device of the target soft pressure plate, and identify the return information returned by the protection device; wherein, the target soft pressure plate includes at least a remote jump sending soft pressure plate and a remote jump receiving soft pressure plate; the return information includes at least a correct or negative confirmation of return calibration or a timeout message not received. When the returned information indicates that the return to calibration is correct, a remote execution command is issued; wherein, the remote execution command is for the protection device to set the actual value of the soft pressure plate status to exit, and after the exit action is completed, to send a status change message as the execution result. Upon receiving the execution result, the corresponding remote control result is output based on the content of the execution result, wherein the remote control result includes at least success or error.

2. The method as described in claim 1, characterized in that, It also includes terminating remote control operation and outputting alarm information when the returned information is a negative confirmation or when no return-to-school message is received after a timeout.

3. The method as described in claim 1, characterized in that, The remote control preset command is to simultaneously send a soft pressure plate to the remote jump and issue an exit action command to the remote jump receiving soft pressure plate within a preset logical scan cycle.

4. The method as described in claim 3, characterized in that, It also includes verifying the legality of the remote control preset command according to preset verification items after the protection device receives the remote control preset command; If the verification passes, a confirmation message confirming the correct return to school will be returned as the feedback information; If the verification fails, a negative confirmation message is returned as the return information; The verification items include at least whether the user has operating permissions, whether the interlocking conditions are met, whether the object exists, and whether the object can be remotely controlled.

5. The method as described in claim 4, characterized in that, The step of outputting the corresponding remote control result based on the execution result includes, If all target soft pressure plates are successfully remotely controlled, the remote control result will be output as successful. If any target soft pressure plate remote control fails, an alarm pop-up will be displayed and subsequent operations will be paused, and a complete error log will be recorded.

6. The method as described in claim 5, characterized in that, It also includes, after identifying the valid line maintenance mark, if identified, simultaneously implementing access control to the operation entry; wherein, the access control to the operation entry includes at least the following: the remote jump send / receive soft pressure plate remote control button on the human-machine interface is automatically grayed out and cannot be clicked; the operator's remote jump soft pressure plate remote control operation interface rejects any operation request; When an operator attempts to engage a locked remote jump soft pressure plate, the system displays a corresponding locking prompt. If it is necessary to forcibly engage the remote jump plate during maintenance, a user with the corresponding permissions needs to enter an advanced authorization code to temporarily unlock the self-lock. Setting the temporary unlock triggers a network-wide audible and visual alarm and records it to the security audit log. If the line maintenance validity flag still exists after the self-locking is released, the system will automatically lock again after the preset safe time threshold is reached.

7. The method as described in claim 6, characterized in that, It also includes unlocking the remote control button of the remote tripping pressure plate and restoring normal remote control operation permissions after the line maintenance valid indicator is cleared to zero; Send a remote preset command to the protection device, and after receiving the correct confirmation of the return calibration of the two pressure plates, send a remote execution command. After the device completes the execution, send a status change message. Compare the status of the pressure plate sent by the protection device with the instructions issued by the background. If they are all consistent, output a recovery reminder message and generate a confirmation record of successful maintenance. If the command fails to execute, an alarm will be triggered immediately.

8. The method as described in claim 7, characterized in that, It also includes recording the preset command response timeout, the command execution response timeout, and the status change message waiting timeout, respectively; If any of the timings reaches the corresponding preset threshold time for the first time, then retry once; If the retry fails, an alarm message will be output and the operation will be terminated; during the retry execution, the maintenance status flag will not be switched.

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