Railway communication signal intelligent lithium iron phosphate backup power monitoring and dynamic switching system

Abstract

This invention relates to the field of railway communication signal power supply and energy storage power management technology, specifically a smart lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals. It includes: collecting individual cell voltage, total voltage change rate, charging and discharging current, and communication load; during charging, performing current drop detection after a cell reaches its protection voltage to distinguish between false full charge and true full charge, and switching to pulse equalization charging when a false full charge occurs; implementing anti-jitter locking after the main control relay is disconnected; during discharging, calculating the backup margin time based on the total voltage change rate, electrochemical degradation mapping, and load status, and generating a dynamically extended protection baseline based on the core business activity indicator; this invention achieves safe disconnection after critical business operations are completed, balancing battery safety and continuous power supply to railway signals.

Description

Technical Field

[0001] This invention relates to the field of railway communication signal power supply and energy storage power management technology, specifically to a smart lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals. Background Technology

[0002] In the daily operation of railway communication and signaling systems, station interlocking equipment, signal centralized monitoring units, and station communication equipment have strict preset uninterrupted power supply time requirements for backup power supply continuity. When external power supply is abnormal or load fluctuations intensify, the monitoring accuracy and switching stability of backup power supply will directly affect the continuous operation of critical business links and the effectiveness of equipment safety protection.

[0003] In traditional methods, backup power supplies are mostly controlled for charging and discharging and cut-off based on static voltage thresholds. Towards the end of charging, they are easily affected by cell polarization, falsely high voltage, and repeated relay operation. During the discharge process, it is difficult to reflect the risk of sudden voltage drop at the end of the lithium iron phosphate battery in a timely manner. Moreover, the switching strategy is usually not dynamically adjusted in conjunction with the core business status of communication signals. Therefore, in critical business processing, there are still problems such as misjudging full charge, delayed cut-off, or premature power outage. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals. Specifically, the technical solution of this invention includes:

[0005] This system is connected in series between the main system power supply circuit and the backup battery system, and includes at least a main control relay, a power sensor, and a controller connected to the main control relay and the power sensor. The controller is configured to implement the following modules:

[0006] The parameter acquisition module is used to acquire real-time individual cell voltage data, real-time total voltage change rate, charging and discharging current data, and real-time communication load operating load of the backup battery system, and to extract the pre-stored static backup cutoff discharge threshold and preset polarization warning line of the system.

[0007] The polarization detection and identification module is used to trigger the current drop detection mechanism to obtain transient voltage drop data during charging, and to perform charging mode switching or output the main control relay cut-off command based on the comparison result of transient voltage drop data and preset polarization warning line.

[0008] The anti-jitter locking module is used to control the main control relay to disconnect in response to the main control relay cut-off command, and to control the main control relay to be in an inactive state based on the current disconnection duration and real-time individual unit voltage data.

[0009] The voltage drop risk prediction module is used to calculate the voltage drop characteristic value based on the real-time total voltage change rate during discharge, and to calculate the standby working margin time in real time.

[0010] The dynamic power distribution module is used to dynamically adjust the protection baseline or output the main control relay cut-off command based on the standby working margin time, the preset critical depletion threshold time, and the real-time communication load operation load.

[0011] Furthermore, the specific logic of the polarization detection and discrimination module, the anti-jitter locking module, and the dynamic power distribution module is as follows:

[0012] The polarization detection and identification module acquires the preset individual cell protection voltage and limits the charging and discharging current data when the real-time individual cell voltage data is greater than or equal to the preset individual cell protection voltage. If the transient drop voltage data is less than the preset polarization warning line, it switches to the preset pulse equalization charging mode. If it is greater than or equal to the preset polarization warning line, it confirms full charging and outputs the main control relay cut-off command.

[0013] The anti-shake locking module releases the engagement prohibition state to allow subsequent charging when the current separation duration is greater than or equal to the preset locking time threshold and the real-time individual voltage data is lower than the preset charging allowable voltage threshold; otherwise, it maintains the locked state where the main control relay is disengaged.

[0014] The power distribution module is dynamically defined. When the backup working margin time is greater than the preset critical depletion threshold time, the normal power supply of the backup battery system is maintained. When the backup working margin time is less than or equal to the preset critical depletion threshold time and a core business activity indicator is identified, the static backup cutoff discharge threshold is subtracted from the preset backup safety voltage value to generate a dynamic extended protection baseline, and the main control relay is forced to remain closed until the business is completed. If there is no core business activity indicator and the real-time individual cell voltage data is less than or equal to the static backup cutoff discharge threshold, a main control relay disconnection command is output.

[0015] Furthermore, the specific operations of the parameter acquisition module to obtain the real-time total voltage change rate include:

[0016] High-frequency sampling is performed on the battery terminals of the backup battery system to obtain discrete voltage time series;

[0017] A sliding window smoothing filter is applied to the discrete voltage time series to remove instantaneous interference voltage data and generate a smooth voltage curve;

[0018] Obtain the slope feature vector of the smooth voltage curve within the previous monitoring time interval at the current time point;

[0019] The absolute value of the slope feature vector is taken and the time-distance weighted average is calculated to obtain the real-time total voltage change rate.

[0020] Furthermore, the system also includes a built-in intelligent power module. The specific operations of the polarization detection and discrimination module in triggering the current sag detection mechanism and acquiring transient fallback voltage data include:

[0021] When the real-time individual cell voltage data reaches the preset individual cell protection voltage, the intelligent power module reduces the charging current value to the preset test current reference.

[0022] After a preset test delay, the real-time tracking voltage value of the backup battery system response is obtained.

[0023] The absolute difference between the real-time individual voltage data and the real-time tracking terminal voltage value is calculated, and the difference is corrected by combining the pre-stored temperature compensation coefficient to generate the corrected voltage drop amount.

[0024] The corrected voltage drop is output as transient voltage drop data.

[0025] Furthermore, the specific operations of the polarization detection and discrimination module in executing the predetermined pulse equalization mode include:

[0026] The pulse width modulation signal generation link inside the system is activated, and a timing pulse signal with a preset interval time is output.

[0027] According to the timing pulse signal, the charging power module configured inside the system is cyclically driven to intermittently inject a limiting current into the backup battery system.

[0028] During the predetermined interval when the current injection is stopped, the terminal voltage data of each cell is collected synchronously, and a static cell terminal voltage data matrix is ​​constructed according to the continuous sampling period and the cell arrangement dimension.

[0029] When all values ​​in the static single-unit terminal voltage data matrix acquired within a continuous preset acquisition period are greater than or equal to the preset polarization warning line, the current pulse equalization charging control process is terminated, and a main control relay cut-off command is generated; when there are values ​​in the static single-unit terminal voltage data matrix that are less than the preset polarization warning line, the current pulse equalization charging mode continues to be executed.

[0030] Furthermore, the method by which the anti-jitter lock module, in conjunction with a state countdown timer, maintains the locked state of the main control relay when it is disengaged includes:

[0031] After obtaining the disconnection flag of the drive signal associated with the disconnection action of the main control relay, start the status countdown timer to count the separation duration;

[0032] Real-time acquisition of external ambient temperature data and battery body temperature data; by querying a preset temperature difference and bias time mapping table, or by executing a proportional-integral adjustment function, the temperature compensation bias time is calculated and generated based on the difference between the external ambient temperature data and the battery body temperature data.

[0033] The preset lock time threshold is dynamically adjusted by superimposing the temperature compensation bias time to obtain the corrected lock determination time requirement.

[0034] When the current separation duration is less than the modified lockout determination time requirement, regardless of whether the real-time individual voltage data is lower than the preset charging allowable voltage threshold, the closing control command to the main control relay is blocked to maintain the disengaged lockout state.

[0035] Furthermore, methods for calculating standby working margin time in real time include:

[0036] Retrieve the pre-stored smooth terminal inflection point voltage data of the discharge characteristics of the lithium iron phosphate material corresponding to the backup battery system.

[0037] Obtain the current total output terminal voltage of the backup battery system, and calculate the current available voltage difference between the current total output terminal voltage and the terminal voltage data at the smooth terminal inflection point;

[0038] Extract the voltage drop feature value sequence with the timestamp closest to the current time and a preset number of consecutive times, and establish a quadratic prediction polynomial with time as the independent variable and voltage drop magnitude as the dependent variable;

[0039] The current available voltage difference is substituted into the quadratic prediction polynomial as the dependent variable to solve for the independent variable, and the positive real roots are extracted as the corresponding time span values ​​to obtain the final standby working margin time.

[0040] Furthermore, the method for generating a dynamic extended protection baseline by subtracting a preset voltage difference from the static standby discharge threshold includes:

[0041] The system performs communication protocol identification and capture on the real-time communication load, extracting interlocking data packets including route occupancy instructions, beacon response messages, and collision avoidance control messages.

[0042] When any of the above interlocking data packets is identified as being in an active process state, the protection mode flag is triggered as an indicator of the presence of active core business.

[0043] After the protection mode flag is triggered, the pre-configured battery cell safe discharge data table is called to map and extract the deepest discharge voltage lower limit warning value that will not induce battery safety hazards.

[0044] The deepest discharge voltage lower limit warning value is added to the preset backup safety voltage value required by the equipment's basic working conditions, and a dynamic extended protection baseline is generated to replace the original protection limit.

[0045] Furthermore, the system also includes a composite switch execution module for performing switching actions in response to the main control relay disconnection command, the method of which includes:

[0046] A collaborative power supply bypass is set up in the composite switch execution module, consisting of a bidirectional AC high-frequency solid-state static switch branch and a mechanical contact main switch circuit connected in parallel.

[0047] When the main control relay is disconnected, the mechanical contact main switch circuit is opened, so that the energy of the conductive load is transferred instantly and the bidirectional AC high-frequency solid-state static switch branch is turned on to maintain continuous flow.

[0048] After a preset collision avoidance protection delay countdown time, the conduction control command for the bidirectional AC high-frequency solid-state static switch branch is disconnected, thereby achieving complete physical current interruption protection.

[0049] Furthermore, the system is also equipped with an isolation verification self-checking program module to prevent resection failure, which is used to perform:

[0050] When the main control relay is disconnected according to the static standby cutoff discharge threshold, or when the target service is confirmed to be completed and the corresponding main control relay is disconnected, the static terminal voltage detection measurement channel connected to the output side of the load terminal is activated.

[0051] Measure and obtain the residual static voltage interference value generated by the parallel capacitor feedback, and compare the residual static voltage interference value with the preset safety isolation measurement threshold value;

[0052] If the residual static voltage interference value is diagnosed as being greater than the preset safety isolation measurement threshold, a low-level physical fault prompt indicating feedback disconnection failure is generated and sent to the monitoring center; if the residual static voltage interference value is less than or equal to the preset safety isolation measurement threshold, the disconnection state is marked as valid and the control system enters a no-power-consumption protection sleep mode.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] 1. This invention establishes a multi-dimensional status monitoring foundation for railway communication signal backup power supply scenarios by continuously acquiring and collaboratively analyzing real-time individual cell voltage data, real-time total voltage change rate, charging and discharging current data, and real-time communication load operating load through a parameter acquisition module. It can extend the traditional single static voltage judgment to a comprehensive evaluation of battery electrochemical status, load status, and service status, thereby enhancing the accuracy of backup power supply monitoring and switching control.

[0055] 2. This invention, through a polarization detection and discrimination module, triggers a current drop detection mechanism at the end of charging, extracts transient voltage drop data, and compares it with a preset polarization warning line. This effectively distinguishes between abnormal full-charge states caused by polarization and true full-charge states, solving the problem of misjudging full charge and premature charging termination due to artificially high cell voltage under traditional static threshold control. By switching to a predetermined pulse equalization charging mode and coordinating with limiting intermittent current injection and collecting static cell terminal voltage data matrix, the true voltage retention capability of each cell after current stoppage is continuously confirmed. This further eliminates surface voltage artifacts at the end of charging, improving the consistency of the entire battery pack and the reliability of true full-charge confirmation. Attached Figure Description

[0056] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0057] Figure 1 A schematic diagram of the modules of the intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals provided in this application embodiment. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0059] A railway communication signal intelligent lithium iron phosphate backup power monitoring and dynamic switching system, which is connected in series between the system power supply trunk and the backup battery system, includes at least a main control relay, a power sensor, and a controller connected to the main control relay and the power sensor. The controller is configured to implement the following modules:

[0060] The parameter acquisition module is used to acquire real-time individual cell voltage data, real-time total voltage change rate, charging and discharging current data, and real-time communication load operating load of the backup battery system, and to extract the pre-stored static backup cutoff discharge threshold and preset polarization warning line of the system.

[0061] The polarization detection and identification module is used to trigger the current drop detection mechanism to obtain transient voltage drop data during charging, and to perform charging mode switching or output the main control relay cut-off command based on the comparison result of transient voltage drop data and preset polarization warning line.

[0062] The anti-jitter locking module is used to control the main control relay to disconnect in response to the main control relay cut-off command, and to control the main control relay to be in an inactive state based on the current disconnection duration and real-time individual unit voltage data.

[0063] The voltage drop risk prediction module is used to calculate the voltage drop characteristic value based on the real-time total voltage change rate during discharge, and to calculate the standby working margin time in real time.

[0064] The dynamic power distribution module is used to dynamically adjust the protection baseline or output the main control relay disconnection command based on the standby working margin time, the preset critical depletion threshold time and the real-time communication load.

[0065] The specific logic of the polarization detection and identification module, the anti-jitter locking module, and the dynamic power distribution module is as follows: The polarization detection and identification module obtains the preset individual protection voltage and limits the charging and discharging current data when the real-time individual voltage data is greater than or equal to the preset individual protection voltage; if the transient drop voltage data is less than the preset polarization warning line, it switches to the preset pulse equalization charging mode; if it is greater than or equal to the preset polarization warning line, it confirms full charging and outputs the main control relay cut-off command.

[0066] The anti-shake locking module releases the engagement prohibition state to allow subsequent charging when the current separation duration is greater than or equal to the preset locking time threshold and the real-time individual voltage data is lower than the preset charging allowable voltage threshold; otherwise, it maintains the locked state where the main control relay is disengaged.

[0067] The power distribution module is dynamically defined. When the standby working margin time is greater than the preset critical depletion threshold time, the normal power supply of the backup battery system is maintained. When the standby working margin time is less than or equal to the preset critical depletion threshold time and a core business active indicator is identified, the static backup cutoff discharge threshold is subtracted from the preset voltage difference to generate a dynamic extended protection bottom line, and the main control relay is forced to remain closed until the business is completed. If there is no core business active indicator and the real-time individual voltage data is less than or equal to the static backup cutoff discharge threshold, the main control relay is output as a disconnect command.

[0068] This embodiment provides a mechanism for monitoring and dynamically switching intelligent lithium iron phosphate backup power supplies for railway communication signals, such as... Figure 1 As shown; specifically, the system is deployed on the backup power supply branch of the station interlocking cabinet, the signal centralized monitoring unit, and the station communication equipment. When the main power supply is normal, it undertakes charging management, and when the main power supply fails, it undertakes discharging power supply and protection switching. The entire implementation process revolves around the same main scenario: a certain intermediate station resumes operation after the night maintenance window ends, and the loads of the turnouts, signals, train control responses, and interlocking communication in the station are gradually restored. The backup battery system first goes through the final charging stage, and then enters the discharging and supply stage in the subsequent mains power interruption event, and finally completes the safe disconnection after the critical business is completed.

[0069] The specific processing procedure is as follows: the parameter acquisition module continuously collects the terminal voltage of each lithium iron phosphate cell, the trend of the total terminal voltage of the entire battery pack, the charging and discharging current, and the operating status of the communication signal load; the real-time total voltage change rate here is not simply for extracting a single numerical parameter, but is used to reflect whether the battery is currently in the flat zone of the discharge platform or has approached the nonlinear drop zone at the end of the discharge.

[0070] For lithium iron phosphate materials, the voltage plateau voltage change rate is lower than the plateau period judgment threshold in most discharge ranges. Simply extracting the instantaneous total voltage is often insufficient to determine the remaining usable time. Once it enters the end, the voltage will show a non-linear negative slope accelerating downward trend. If the static threshold is still used for hard cutting, it is easy to conflict with the railway site operation rhythm. Therefore, the system simultaneously monitors the rate of change while collecting the voltage and integrates the remaining voltage amplitude with the voltage drop rate characteristics.

[0071] When the system is charging and detects that the voltage of a certain cell has reached the preset cell protection voltage, the polarization detection and discrimination module does not immediately output the main control relay cut-off command, but first triggers the current drop detection mechanism. The physical basis is that the increase in cell voltage at the end of charging may be due to actual electrochemical full charging, or it may just be a surface voltage rise caused by polarization. If it is the latter, once the charging current is reduced or removed, the terminal voltage will drop at a rate greater than the preset slope. If it is the former, the terminal voltage can still be maintained at a high level during the test.

[0072] The system obtains transient voltage drop data and compares it with a preset polarization warning line. If the voltage drop is lower than the warning line after the drop, it indicates that the current high voltage is mainly driven by the charging current and has not formed a stable saturation state. The system identifies this full charge as abnormal and switches to the predetermined pulse equalization charging mode. If the voltage drop is still higher than or equal to the warning line after the drop, it indicates that the cell is close to being fully charged. The system outputs a main control relay cutoff command to stop charging.

[0073] After the main control relay has disengaged according to the full charge determination, the anti-jitter locking module locks the relay. The reason for this setting is that the individual cell voltage often fluctuates slightly around the protection point at the end of the charging period. If there is no locking window, the relay will repeatedly engage and disengage, which can easily cause heat accumulation and arcing damage on the contacts. Therefore, the system starts a state countdown timer after disengagement. Only when the separation duration reaches the locking time threshold and the individual cell voltage has dropped below the preset charging allowable voltage threshold will the engagement prohibition state be released, allowing charging to be connected again; otherwise, the disengagement state will be maintained to prevent short-cycle repeated operation.

[0074] When the mains power is interrupted abnormally and the system enters the discharge state, the voltage drop risk prediction module starts to calculate the voltage drop characteristics based on the real-time total voltage change rate, the plateau constraint time period and the current discharge current, and estimates the backup working margin time in combination with the pre-stored electrochemical degradation mapping relationship. The electrochemical degradation mapping relationship here can be established by historical tests of the same type of battery under different cycle numbers, different temperatures and different rate conditions, and is used to reflect the actual situation of the plateau shortening and the premature end-of-life degradation after aging.

[0075] At the underlying data structure implementation of the system, the electrochemical decay mapping relationship is a multi-dimensional data lookup matrix or high-order fitted surface function with the number of cycles, operating temperature and discharge rate as multi-dimensional input indices, and the duration of discharge plateau and terminal voltage at the final inflection point as output variables.

[0076] The dynamic power distribution module compares the estimated backup working margin time with the critical depletion threshold time. If the margin time is still sufficient, normal power supply is maintained. If the margin time is approaching the danger boundary, the decision is no longer based solely on whether the voltage has reached the threshold, but also on whether the current communication signal load is in a core service active state. If a core service active indicator is identified, such as route locking, turnout conversion confirmation, beacon response message exchange, or collision avoidance control message transmission, the system generates a dynamic extended protection baseline, allowing the backup power supply to continue to remain closed without exceeding the cell's safe discharge boundary until the core service is completed.

[0077] This is not simply about extending the power supply time, but about rearranging the order of battery protection and driving safety: prioritizing ensuring that ongoing critical links are not interrupted; conversely, if no active core business indicator is detected, the system reverts to the normal safety strategy, comparing the real-time cell voltage with the static backup cutoff discharge threshold, and immediately issuing a cutoff command when the cutoff condition is met, thus avoiding unnecessary deep discharge.

[0078] As an anomaly handling mechanism, if the parameter acquisition module detects an abnormal voltage sampling of a single unit, loss of load status data, or unreliable generation of total voltage change rate, the system will prioritize a conservative strategy. During the charging phase, if effective polarization identification cannot be completed, the system will switch to a conservative equalization charging state that limits the current and send a sampling anomaly alarm to the upper-level monitoring station instead of directly processing it as a true full charge.

[0079] During the discharge phase, if the operating load of the communication load cannot be identified, the dynamic extended protection bottom line mode will not be entered. Instead, the disconnection will be performed according to the static safety threshold to prevent uncontrolled deep discharge when the service status is unclear. If the feedback status after the main control relay executes the command is inconsistent with the expectation, the current power supply path will be maintained and the relay execution abnormality will be reported.

[0080] In the same station scenario, before the resumption of operation at night, the backup battery was in the late stage of charging, and one of the cells briefly touched 3.60V. The system did not immediately stop charging, but instead momentarily reduced the charging current for detection. It was found that the voltage of the cell dropped significantly, indicating that its high voltage mainly came from polarization accumulation. Therefore, the system switched to pulse equalization charging, so that the cells gradually became more consistent during intermittent rest.

[0081] Once the entire battery pack is fully charged, the main control relay disengages and is prohibited from re-engaging within the lockout period. Several hours later, an external power grid failure occurs, and the backup battery takes over power supply. During the initial discharge phase, the total voltage changes gradually, and the system maintains routine monitoring. As a down train enters the approach section, route locking and response message exchange are being performed within the station. At this point, the battery is nearing its final platform, and the system predicts that the available remaining time is approaching the critical value. Due to the detection of active core business operations, the system temporarily adopts a dynamic extension of the protection baseline to maintain power supply until the route processing is completed.

[0082] After the train passes through the safe section and the relevant message links are completed, the system will then perform the protection cut-off. The purpose of this step is to upgrade the lithium iron phosphate backup power supply from a rigid protection mode driven by static voltage threshold to a flexible power supply mode that combines electrochemical state recognition, relay action vibration suppression, and business importance coupling. This will prevent abnormal full charge and accidental cut-off caused by individual cell polarization at the charging end, avoid power loss of critical business during discharge, and take into account both battery safety and the continuous availability of railway signals.

[0083] Furthermore, to ensure consistency in the criteria throughout the text, in this embodiment, the real-time individual cell voltage data refers to the set of valid individual cell voltages participating in the protection judgment at the current moment when performing threshold comparisons. When a single comparison result needs to be output, the controller defaults to taking the lowest individual cell voltage in the set of valid individual cell voltages as the judgment input, thus maintaining the same comparison dimension as the static standby cutoff discharge threshold, the preset charging quasi-acceptable voltage threshold, and the preset polarization warning line. The descriptions of a single cell, each section of cells, and individual aged cells in the text are only used to explain the sampling source or the source of the anomaly, and do not change the fact that the protection judgment still uses the lowest individual cell voltage in the set of valid individual cell voltages as the execution basis.

[0084] Furthermore, to ensure consistency in terminology, the false full state mentioned in this document corresponds to the abnormal full charge state in the embodiments. The charge cut-off, disconnection, and cut-off commands all correspond to the output main control relay cut-off command when involving the action of the main control relay. The disconnection and disconnection commands all correspond to the main control relay disconnection state when involving the current mechanical state of the main control relay. The above descriptions are only simplified terms for the purpose of writing and do not change the control objects of each module and their execution order.

[0085] Furthermore, once the dynamic power distribution module identifies the core service activity indicator, it forces the main control relay to remain closed until the service processing that triggered the core service activity indicator is completed. This means maintaining the closure before the dynamic extended protection threshold is reached. If, before the service is completed, a single cell voltage approaches the dynamic extended protection threshold, a single cell voltage difference abnormally expands, a temperature rise is abnormal, or an insulation abnormality occurs, the system prioritizes battery safety protection and outputs a main control relay disconnection command. Thus, service continuity gives way to cell safety boundaries, avoiding the misinterpretation of maintaining the closure as unconditional delayed power supply.

[0086] Furthermore, the specific operations of the parameter acquisition module to obtain the real-time total voltage change rate include: performing high-frequency sampling on the battery terminals of the backup battery system to obtain a discrete voltage time series; performing sliding window smoothing filtering on the discrete voltage time series to remove instantaneous interference voltage data and generate a smooth voltage curve; obtaining the slope feature vector of the smooth voltage curve within the previous monitoring time interval at the current time point; taking the absolute value of the slope feature vector and performing time distance weighted average calculation to obtain the real-time total voltage change rate.

[0087] This embodiment provides a mechanism for obtaining the real-time total voltage change rate. Specifically, in the aforementioned same station scenario, judging the backup battery status solely by the total voltage value at a certain moment is still insufficient, because the operation of the switch in the station, the sudden transmission of the communication module, the recharging of the filter capacitor, etc., will introduce short-term spikes or drops. If these instantaneous disturbances are directly regarded as the battery status, the risk of misjudgment will be amplified.

[0088] The specific processing procedure is as follows: the system performs high-frequency sampling on the battery terminals to form a discrete voltage sequence arranged in time order; the high-frequency sampling is used to observe the difference between rapid disturbances and slow decay; a sliding window smoothing filter is used to remove instantaneous disturbances that deviate significantly from the adjacent trend within the window, resulting in a smooth voltage curve that is closer to the actual discharge trajectory of the battery; the smoothed curve is not intended to eliminate all details, but to retain the overall downward trend of the battery body under the current operating conditions and shield the false fluctuations caused by load switching and electromagnetic interference;

[0089] Based on this, the system extracts the slope feature vector within a monitoring time interval prior to the current moment; this can be understood as observing the downward trend of several recent short time intervals side by side, rather than just looking at a single point; for example, in a simplified test model, the slope formed by the four most recent sampling segments can be represented in sequence as the rate of change being lower than the first rate of decrease threshold, the rate of change being lower than the first rate of decrease threshold, the rate of change being higher than the second rate of decrease threshold, and the rate of change being higher than the third rate of decrease threshold. Therefore, the segment closer to the current moment can better reflect the true state of the battery entering the terminal stage.

[0090] The system takes the absolute value of these slopes and then performs a time-distance weighted average, giving higher reference weight to the recent downward trend and moderately reducing the influence of earlier periods, thus outputting a total voltage change rate that is more suitable for real-time decision-making. The physical meaning of this processing method is that when lithium iron phosphate batteries approach the end of discharge, they do not drop in a step-like manner, but usually show an increasing trend in the rate of decline over a recent period. The weighting mechanism is used to highlight this deteriorating trend closer to the current moment, enabling the system to detect the cliff risk earlier than a single threshold.

[0091] As an anomaly handling mechanism, if sampling channel jitter, missing timestamps, or partial data interruption occur during high-frequency sampling, the system can use adjacent valid segments to fill in the gaps, or temporarily extend the monitoring time interval before generating the rate of change. If the quality of continuous data is insufficient to support a reliable judgment, the system will not output a high-reliability rate of change to downstream modules, but will instead mark the rate of change as unavailable and fall back from discharge protection to static threshold mode to avoid making aggressive decisions based on distortion trends.

[0092] During the power outage and power supply restoration process at the same station, although the total voltage reading had not yet reached the cutoff value at a certain moment, the recent multiple sampling windows showed that the rate of decline of the smooth curve had been continuously accelerating. Based on this, the system determined that the battery had deviated from the typical flat plateau and was entering the terminal decay stage. Therefore, it provided this status to the subsequent margin time judgment module in advance, instead of waiting until the total voltage suddenly dropped before being passively cut off.

[0093] The purpose of this step is to extract a trend quantity that is more representative of the battery's true remaining power supply capacity from the noise-affected terminal voltage signal, thereby enabling early identification of the risk of precipitous power loss.

[0094] Furthermore, the system also includes a built-in intelligent power module. The specific operations of the polarization detection and discrimination module in triggering the current drop detection mechanism and obtaining transient voltage drop data include: when the real-time cell voltage data touches the preset cell protection voltage, the intelligent power module reduces the charging current value to the preset test current reference; after a preset test delay, the real-time tracking terminal voltage value of the backup battery system response is obtained; the absolute difference between the real-time cell voltage data and the real-time tracking terminal voltage value is calculated, and the difference is corrected by combining the pre-stored temperature compensation coefficient to generate the corrected voltage drop amount; the corrected voltage drop amount is output as transient voltage drop data.

[0095] This embodiment provides a current drop detection mechanism based on intelligent power modules. Specifically, although the aforementioned scheme can distinguish between true and false full charge when a single cell touches the protection voltage, if the voltage is observed after the ordinary relay is cut off, it may still be affected by mechanical action lag, line inductance and instantaneous temperature rise, resulting in the observed drop amount being mixed with external factors.

[0096] Therefore, this embodiment further introduces an intelligent power module to more precisely extract the test current voltage drop and fall-off voltage. The intelligent power module includes at least a series-connected controllable DC chopper and a shunt resistor matrix in its hardware topology. The controller sends duty cycle adjustment commands to the controllable DC chopper to achieve stepless voltage reduction and precise current limiting control of the charging current.

[0097] The specific processing procedure is as follows: when a single cell reaches the preset single cell protection voltage, the intelligent power module does not disconnect the main power supply path as a whole, but first quickly reduces the charging current to the preset test current reference. The physical significance of doing so is to preserve the most basic circuit stability, while suppressing the ohmic voltage drop and polarization accumulation caused by high current charging, so that the single cell terminal voltage is closer to its static steady state. After the preset test delay time, the system collects the real-time tracking terminal voltage value at that moment. The reason for retaining a short delay is to allow the surface charge to redistribute and the instantaneous voltage drop on the wires and connectors to gradually subside, thereby avoiding mistaking the transition waveform at the moment of switching as the intrinsic response of the battery.

[0098] The system calculates the difference between the instantaneous single-cell voltage and the terminal voltage tracked after a delay to obtain the drop-off amount, and then corrects it using a temperature compensation coefficient. Because the polarization characteristics of lithium iron phosphate cells are not consistent at low and high temperatures, the same drop-off amount may correspond to different actual levels of charge under different temperature conditions. Temperature compensation is equivalent to correcting the amplification or reduction of the impact of the environment on the drop-off amount, so that the final output transient drop-off voltage data can better reflect the electrochemical state itself, rather than being affected by seasonality, cabinet heat dissipation, or accidental disturbances caused by the temperature rise of the battery itself.

[0099] In an illustrative test process, the state of the individual cell before the test can be recorded as the first sampling point, and the state acquired after a delay when the test current is low can be recorded as the second sampling point. If the difference between the first sampling point and the second sampling point is greater than or equal to a preset judgment threshold, it indicates that the individual cell has a significant external voltage rise under the action of a large charging current. If the difference between the first sampling point and the second sampling point is less than the preset judgment threshold, it indicates that its terminal voltage has stabilized. The system does not need to limit the specific numerical value in the implementation method; it only needs to complete the classification based on the preset warning line.

[0100] Furthermore, to avoid the real-time tracking terminal voltage value being interpreted as the total terminal voltage of the entire battery pack, in this embodiment, when the real-time tracking terminal voltage value is used to calculate the difference between the real-time tracking terminal voltage value and the real-time individual cell voltage data, it refers to the individual cell terminal voltage tracking value corresponding to the target cell that triggers the protection determination; when multiple cells approach the preset individual cell protection voltage at adjacent times, the controller performs transient drop detection on the corresponding cells according to the triggering sequence and outputs their respective transient drop voltage data, without cross-mixing the sampled values ​​of different cells in the calculation;

[0101] As an anomaly handling mechanism, if the intelligent power module experiences a response delay, the test current fails to stabilize to the reference value, or the temperature sensor fails to sample during the current reduction process, the detection result is marked as low confidence. For low confidence results, the system can repeat the instantaneous drop detection once. If a reliable drop amount cannot be obtained after repetition, the system switches to a limited pulse equalization charging mode instead of directly determining it as a true full charge to prevent accidental disconnection of charging. If the tracking voltage value rises abnormally during the test, it is first determined to be an anomaly in the measurement link or sampling reference ground, and a hardware diagnostic alarm is generated.

[0102] During the nighttime recharging of the backup batteries at the aforementioned station, a cell with a high degree of aging quickly triggered the protection point under a large charging current. After the intelligent power module reduced the charging current to the test current reference, the terminal voltage of the cell was measured to have dropped significantly within a short delay. After correction based on the high temperature inside the cabinet, it was still below the polarization warning line. Based on this, the system determined that it was in a false full state and did not perform a cut-off. Conversely, another cell in good condition only showed a slight drop after the same operation, and after correction, it was still above the warning line. Therefore, it was determined to be a true full charge.

[0103] The purpose of this step is to obtain a purer fallback voltage characteristic with less influence from mechanical switching and thermal disturbances, thereby enabling a reliable distinction between polarization overcharge and true full charge.

[0104] Furthermore, the specific operations of the polarization detection and discrimination module in executing the predetermined pulse equalization mode include: activating the pulse width modulation signal generation link inside the system and outputting a timing pulse signal with a preset interval time;

[0105] According to the timing pulse signal, the charging power module configured inside the system is cyclically driven to intermittently inject a limiting current into the backup battery system.

[0106] During the predetermined interval when the current injection is stopped, the terminal voltage data of each cell is collected synchronously, and a static cell terminal voltage data matrix is ​​constructed according to the continuous sampling period and the cell arrangement dimension.

[0107] When all values ​​in the static single-cell end-voltage data matrix acquired within a continuous preset acquisition period are greater than or equal to the preset polarization warning line, the current pulse equalization control process is terminated, and a main control relay cut-off command is generated.

[0108] If there is a value in the static single-cell terminal voltage data matrix that is lower than the preset polarization warning line, continue to execute the current pulse equalization charging mode.

[0109] This embodiment provides an execution mechanism for a predetermined pulse equalization charging mode. Specifically, in the aforementioned charging end scenario, if a false full charge is identified by a single instantaneous drop detection and then the regular high-current charging is immediately resumed, some cells may still rapidly rise again while others have not been fully replenished, resulting in limited improvement in the overall consistency of the group. Therefore, this embodiment further introduces an intermittent injection pulse equalization charging method.

[0110] The specific processing procedure is as follows: The system activates the internal pulse width modulation signal generation link and outputs a timing pulse with a preset interval time to drive the charging power module to inject a limiting current into the battery pack. The purpose of using a limiting current instead of a conventional large current is to slow down the polarization accumulation rate of individual cells, allowing more time for ion diffusion and rebalancing between cell states. The interval time is set to observe the cell terminal voltage, which is closer to the static steady state, during the current-stop period, rather than observing its terminal voltage change under the continuous action of the charging current.

[0111] Among them, the timing pulse signal is a square wave signal with an adjustable duty cycle. Its pulse width range is configured to allow the active ions inside the cell to complete the diffusion for an effective duration, and the preset interval time is greater than or equal to the time constant of the natural fallback of the polarization voltage of the lithium iron phosphate cell.

[0112] During each interval of flow interruption, the system synchronously collects the stationary terminal pressure of each cell, forming a stationary cell terminal pressure data matrix. This matrix can be understood as an arrangement of several consecutive sampling periods × several cells. For example, three intermittent samplings correspond to three rows, and different cells correspond to multiple columns. If, within several consecutive sampling periods, all cells reach or exceed the polarization warning line in the stationary state, it indicates that not only does the instantaneous terminal pressure increase, but it can also be maintained within the target range after the flow is stopped, thus possessing true full-charge characteristics. At this time, pulse equalization is stopped and a cut-off command is output. If any cell in the matrix is ​​still below the warning line during stationary conditions, it indicates that the cell has not actually been replenished, and the system continues to execute the current pulse equalization.

[0113] The physical basis of this mechanism is that the balanced filling of lithium iron phosphate cells should not only be judged by the instantaneous high voltage under the current state, but also by whether a relatively high terminal voltage can be maintained after the current is stopped; if the warning conditions are met for multiple consecutive sampling cycles, it means that it is not an illusion caused by accidental temperature rise, pulse injection rise or instantaneous surface charge, but rather that the overall process tends to be stable and saturated.

[0114] Furthermore, to ensure that all values ​​in the stationary single-cell terminal voltage data matrix have a consistent judgment caliber, in this embodiment, all values ​​are limited to the stationary sampled values ​​of each valid single cell within the corresponding sampling period after the current injection is stopped; if a single cell experiences invalid sampling, out-of-bounds drift, or timestamp mismatch within the period, the corresponding value of that single cell will not be included in the valid matrix of the current period, and the period will not be included in the continuous preset acquisition period; thus, the system only performs full charge confirmation using the stationary single-cell terminal voltage data matrix formed under complete, same period, and same sampling conditions;

[0115] As an anomaly handling mechanism, if individual cell data is missing during a certain intermittent sampling period, that period will not be considered a valid confirmation period, and the system will continue to maintain pulse equalization charging and wait for the next complete sampling; if multiple consecutive samplings are missing, the system can switch to low current constant current charging mode and report the sampling link anomaly; if the battery temperature rises rapidly or the cell voltage difference continues to expand during pulse equalization charging, the system will immediately reduce the pulse duty cycle, and if necessary, terminate the current equalization charging and switch to fault protection state.

[0116] Inside the aforementioned station cabinet, after a backup battery group was identified as falsely full by a sudden drop detection, the system entered pulse equalization charging. During the first three intermittent cycles, the static terminal voltage of most individual cells had stabilized, but some aging cells still dropped below the warning line after the current was stopped, so the system continued pulse charging. Only after the static terminal voltage of all individual cells remained above the warning line in subsequent consecutive cycles did the system confirm that the entire group was truly fully charged and cut off the charging path.

[0117] The purpose of this step is to eliminate the surface voltage artifact at the end of the charging process by using a cycle of current injection, rest, and retesting, thereby achieving more reliable balanced charging and confirmation of a true full charge.

[0118] Furthermore, the method for the anti-jitter locking module to maintain the locked state of the main control relay being disconnected by combining the state countdown timer includes: after obtaining the drive signal disconnection flag associated with the main control relay disconnection action, starting the state countdown timer to count the separation duration;

[0119] Real-time acquisition of external ambient temperature data and battery body temperature data; by querying a preset temperature difference and bias time mapping table, or by executing a proportional-integral adjustment function, the temperature compensation bias time is calculated and generated based on the difference between the external ambient temperature data and the battery body temperature data.

[0120] The preset lock time threshold is dynamically adjusted by superimposing the temperature compensation bias time to obtain the corrected lock determination time requirement.

[0121] When the current separation duration is less than the modified lockout determination time requirement, regardless of whether the real-time individual voltage data is lower than the preset charging allowable voltage threshold, the closing control command to the main control relay is blocked to maintain the disengaged lockout state.

[0122] This embodiment provides a vibration-damping lock mechanism with temperature compensation. Specifically, in the aforementioned solution, even if a lock time has been set, if the lock time is always fixed, there may still be a mismatch problem when the seasonal temperature difference exceeds the preset allowable range or when the battery body has obvious self-heating. This is because the terminal voltage drop speed after the relay is disconnected, the charge dissipation speed on the battery surface, and the thermal state near the contact are all related to the temperature difference between the ambient temperature and the battery body.

[0123] Specifically, the distribution ratio adjustment generation process refers to: a linear mapping table or proportional-integral adjustment function with temperature difference as the input independent variable and offset time as the output dependent variable is stored in the controller in advance. The system directly outputs the corresponding duration value as the temperature compensation offset time by querying the mapping table or executing the function calculation.

[0124] The specific processing procedure is as follows: After the main control relay is disconnected, the status countdown timer starts counting the separation duration; at the same time, the system collects the ambient temperature of the cabinet and the temperature of the battery body in real time; when the temperature difference between the two is large, it usually means that the battery has just undergone a large current charge and the internal cells and connectors are still in the thermal equilibrium reconstruction stage. At this time, the terminal voltage drop and polarization decay have not yet been completed; if the relay is allowed to re-engage just because the individual cell voltage has briefly dropped below the charging threshold, it is very easy to form a high-frequency repetitive opening and closing action; therefore, the system generates a temperature compensation bias time based on the distribution of the difference between the external ambient temperature and the battery body temperature, which is used to extend or correct the original lock-up time;

[0125] A simplified test model can be used to help understand this: if the temperature difference between the environment and the battery is less than the set first temperature difference threshold, the compensation bias time is set to the first numerical level, indicating that the battery has approached a thermally stable state; if the temperature difference between the battery and the environment is greater than the set second temperature difference threshold, the compensation bias time is increased to the second numerical level to configure a matching cooling and rest observation cycle.

[0126] The system uses the revised lockout determination time requirement as the standard. As long as the current separation duration has not reached the requirement, the reclosing command will be blocked and the lockout will not be released due to short-term voltage changes. The engineering basis for this design is that relay anti-shake is not only a voltage criterion issue, but also involves thermal state and mechanical life. The greater the temperature difference, the more likely the system is to be in a high-stress transition state at the end of charging, and the less suitable it is for frequent mechanical reclosing.

[0127] As an abnormal handling mechanism, if the ambient temperature sensor is abnormal but the battery body temperature is normal, the average effective ambient temperature over the most recent period can be used as a temporary substitute; if both types of temperature data are missing, the system will revert to a conservative locking mode with a preset locking time threshold, and early unlocking will not be allowed; if the relay is detected to be stuck or the feedback contact state is inconsistent with the control command, subsequent engagement attempts will be stopped and an actuator fault will be reported.

[0128] After the nighttime power replenishment at the same station was completed, the ambient temperature inside the cabinet was low, while the battery itself remained at a high temperature due to continuous charging. The system judged that the temperature difference indicated that the polarization and thermal state had not been fully released, so it added a compensation time in addition to the basic lock-in time. Although some individual cells had dropped back below the acceptable charging voltage after a few minutes, the system still blocked the recharging connection because the corrected lock-in judgment time had not been met, thereby avoiding short-cycle jitter of the relay.

[0129] The purpose of this step is to introduce thermal conditions into the relay debounce control, thereby achieving adaptive correction of the lock-in time under different environmental conditions and reducing the risk of contact erosion and false reclosing.

[0130] Furthermore, the method for calculating the standby working margin time in real time includes: retrieving the smooth terminal voltage data of the discharge characteristics of the lithium iron phosphate material corresponding to the backup battery system from the pre-stored data.

[0131] Obtain the current total output terminal voltage of the backup battery system, and calculate the current available voltage difference between the current total output terminal voltage and the terminal voltage data at the smooth terminal inflection point;

[0132] Extract the voltage drop feature value sequence with the timestamp closest to the current time and a preset number of consecutive times, and establish a quadratic prediction polynomial with time as the independent variable and voltage drop magnitude as the dependent variable;

[0133] The current available voltage difference is substituted into the quadratic prediction polynomial as the dependent variable to solve for the independent variable, and the positive real roots are extracted as the corresponding time span values ​​to obtain the final standby working margin time.

[0134] This embodiment provides a real-time calculation mechanism for standby working margin time. Specifically, in the aforementioned cliff risk prediction process, if the remaining working time is judged solely based on whether it is close to the static cutoff voltage, it is often difficult to adapt to lithium iron phosphate batteries under different aging levels, different discharge rates, and different load rhythms. Especially in railway communication signal scenarios, the load is not constant, and route processing, transponder communication, and interlocking processing may all bring about phased current fluctuations. Therefore, it is necessary to couple the difference between the current total voltage and the inflection point voltage with the accelerating trend of voltage drop.

[0135] The specific processing procedure is as follows: the system retrieves the end-pressure data of the smooth terminal inflection point that matches the current battery material system from the pre-stored characteristic library; this end pressure is not the final absolute cutoff value, but rather represents the position where the battery begins to significantly deviate from the stable platform and enter the rapid degradation front.

[0136] The system acquires the current total output voltage and calculates the current available voltage difference between it and the inflection point voltage. This difference can be understood as how much buffer space is left before entering the dangerous decay zone. Then, the system extracts several recent consecutive voltage drop characteristic values ​​and establishes a secondary prediction relationship for short-term trends. The reason for using this trend extrapolation is not to perform complex mathematical solutions, but because the deterioration at the end of the discharge is usually not completely linear: the absolute value of the initial slope is less than the set threshold, and then the absolute value of the slope increases non-linearly.

[0137] By establishing a short-term prediction relationship using the most recent set of continuous feature values, the accelerating deterioration trend within the current period can be well reflected. Substituting the current available voltage difference into this model yields a corresponding time span, which serves as a reserve working margin. In the simplified test model, if the voltage drop amplitude of the three most recent segments shows an increasing characteristic, it indicates that the decline is accelerating. If the difference between the current overall output voltage and the voltage data at the smooth terminal inflection points falling within the first, second, and third threshold intervals is less than the preset safety threshold, the derived margin time will be significantly shortened. Conversely, if the recent segment's voltage drop amplitude remains relatively stable, even if the current overall voltage has not reached the preset high potential reference, there may still be a certain buffer time. This time is closer to the actual business concern of how long the supply can remain stable, rather than simply the current voltage.

[0138] As an anomaly handling mechanism, if the number of extracted sudden drop feature values ​​is insufficient, for example, due to the recent start of discharge or interruption of sampling data, the system can use the most recently available shorter sequence for conservative estimation, or temporarily output a low-confidence margin time according to the static margin strategy; if the calculated time span is an outlier, such as being too small or significantly inconsistent with the current discharge state, the system can trigger a secondary verification, and output the result after restoring consistency with the discharge current and historical voltage; if a reliable result still cannot be formed, the downstream module will revert to the static cutoff strategy.

[0139] After the power grid outside the same station fails, the backup battery power supply is relatively stable in the first ten minutes. The current available voltage difference calculated by the system is sufficient, and the recent voltage drop characteristics are also relatively smooth. Therefore, the backup working margin time is judged to be sufficient. As the train approaches and the communication load increases, the voltage drop characteristics of the recent segments become more severe. The difference between the current total voltage and the final inflection point also narrows rapidly. Based on this, the system adjusts the backup working margin time down and provides this result to the subsequent dynamic power distribution module.

[0140] The purpose of this step is to transform the long and steep discharge characteristics of lithium iron phosphate platforms into a margin time representation that can be used for real-time power supply decisions, thereby enabling risk assessment that is earlier and closer to business needs than static voltage thresholds.

[0141] Furthermore, the method for generating a dynamic extended protection baseline by subtracting a preset voltage difference from the static standby cutoff discharge threshold includes: performing communication protocol identification and capture on the real-time communication load operating load, and extracting interlocking related data packets including route occupancy instructions, beacon response messages, and anti-collision control messages;

[0142] When any of the above interlocking data packets is identified as being in an active process state, the protection mode flag is triggered as an indicator of the presence of active core business.

[0143] After the protection mode flag is triggered, the pre-configured battery cell safe discharge data table is called to map and extract the deepest discharge voltage lower limit warning value that will not induce battery safety hazards.

[0144] The deepest discharge voltage lower limit warning value is added to the preset backup safety voltage value required by the equipment's basic working conditions, and a dynamic extended protection baseline is generated to replace the original protection limit.

[0145] This embodiment provides a mechanism for generating a dynamically extended protection baseline. Specifically, based on the aforementioned margin time prediction, knowing only that the battery charge is approaching the safe discharge lower limit is insufficient to determine whether immediate disconnection is necessary. This is because in railway communication signaling systems, the consequences of interrupting different services differ beyond the tolerable safety threshold. The safety levels of normal state uploading, non-critical polling, and ongoing route locking, beacon response, and collision avoidance control are significantly different. Therefore, this embodiment further incorporates the service activity status of the communication protocol layer into the discharge baseline adjustment logic.

[0146] The specific processing procedure is as follows: The system performs protocol identification and capture on the real-time communication load, and extracts messages or instructions that can directly represent the execution of key services from the interlocking associated data packets; for example, a route occupancy instruction indicates that the train path has entered the occupancy and confirmation stage, a beacon response message indicates that train control information is being exchanged, and a collision avoidance control message indicates that the safety protection logic is running; as long as any one of these interlocking associated data packets is identified as an active process state, the system triggers the protection mode flag bit and marks the current service as an active core service;

[0147] Once this protection mode is entered, the system does not explore the discharge threshold without limit. Instead, it calls the pre-configured battery cell safety discharge data table, extracts the deepest discharge voltage lower limit warning value that will not induce battery safety hazards under the current conditions, and then adds the backup safety voltage value required for the basic operation of the equipment to generate a dynamic extended protection bottom line. The bottom line obtained in this way is essentially a safe intersection between the cell not being allowed to enter the dangerous deep discharge zone and the equipment being required to maintain at least the basic operating voltage, which is used to temporarily replace the original static cut-off protection limit.

[0148] Furthermore, in order to maintain consistency with the static standby cutoff discharge threshold minus the preset voltage difference, the above-mentioned dynamic extended protection baseline is generated using an equivalent conversion method: first, the target protection baseline that is temporarily allowed to be lowered is determined based on the safety discharge data table and the basic working requirements of the equipment; then, the difference between the static standby cutoff discharge threshold and the target protection baseline is registered as the preset voltage difference, and the controller performs threshold shifting accordingly.

[0149] That is, the preset voltage difference is not an arbitrarily given constant, but a controlled difference obtained by combining the current temperature, aging level, individual consistency status and the minimum operating voltage requirement of the equipment. Therefore, the static standby cutoff discharge threshold minus the preset voltage difference and the target protection line obtained by superimposing the safety lower limit warning value and the equipment standby safety voltage value are two ways of expressing the same protection result in this embodiment. The former is used for fast calculation at the execution layer, and the latter is used for source constraints and safety verification.

[0150] In the simplified test model, the static cutoff line can be understood as the conventional boundary, the deepest discharge warning value as the absolute safety lower limit, and the equipment backup safety voltage as the minimum operating margin. The dynamic extension of the protection bottom line is not simply moving the cutoff line down arbitrarily, but forming a new boundary after retaining the basic operating margin above the absolute safety lower limit. Therefore, it still belongs to controlled flexible protection, rather than abandoning protection.

[0151] Furthermore, in the controller execution layer, the safety lookup table and the business voltage requirement can be superimposed first, and then the preset voltage difference can be calculated. If the calculation result is less than zero, it means that the current static cutoff discharge threshold is no higher than the acceptable dynamic protection line. At this time, the system will set the preset voltage difference to zero and will not continue to lower it. If the calculation result is too large, so that the dynamic extension protection line will approach or fall below the safety lower limit of any single cell, the system will cut off the difference according to the safety lower limit. This ensures that the dynamic extension only occurs above the cell safety boundary and will not exceed the discharge safety red line due to business priority.

[0152] As an anomaly handling mechanism, if protocol identification and capture fails, message content is missing, or business status cannot be confirmed, the system will not trigger the core business activity flag and will still perform conventional protection according to the static cutoff discharge threshold. If the battery cell safety discharge data table is missing the corresponding item for the current temperature or aging level, the data of the previous safety level will be used to prevent the threshold from being excessively lowered. If a sharp increase in single-cell voltage difference, abnormal temperature rise, or insulation abnormality is detected during dynamic extension, the system will prioritize battery safety disconnection and report a high-level fault even if the core business has not been completed, because continuing to supply power at this time may cause higher-level risks.

[0153] In a power outage scenario at the same station, the system predicts that the remaining battery time is approaching the critical boundary, while the station is currently processing route locking and beacon response for a downlink train. The protocol identification module detects that the associated interlocking message is still active, thus triggering the protection mode flag. The system looks up the table to find the deepest acceptable discharge boundary of the cell under the current temperature and aging level, and adds the minimum operating voltage margin for maintaining interlocking and communication on top of it. First, the target dynamic extended protection baseline is obtained, and then the preset voltage difference corresponding to the static standby cutoff discharge threshold is calculated. The controller replaces the original static limit switch with the lowered protection line. Above this baseline, the main control relay remains closed until the critical business message ends before being disconnected.

[0154] The purpose of this step is to couple the importance of railway signaling services with the battery safety boundary, so as to achieve a controlled discharge strategy that ensures uninterrupted power supply during critical moments and no discharge during non-critical moments.

[0155] Furthermore, to ensure the comparability of the voltage values ​​in this embodiment, the static backup cutoff discharge threshold, the deepest discharge voltage lower limit warning value, the dynamic extended protection bottom line, and the real-time individual voltage data used for comparison are all calculated using the individual voltage criterion dimension within the controller.

[0156] If the preset backup safety voltage value required for the basic operation of the equipment comes from the total voltage demand of the whole machine side, the bus side, or the whole battery pack side, the controller first converts the total voltage demand into the corresponding equivalent voltage margin of the individual cells based on the current number of effective series-connected cells, and then adds it to the warning value of the deepest discharge voltage to obtain the target dynamic extended protection bottom line for individual cell comparison. After this processing, the subsequent actions of subtracting the preset voltage difference and comparing the real-time individual cell voltage data are all in the same dimension and the same object level, avoiding the ambiguity of directly comparing the individual cell voltage and the whole pack voltage.

[0157] Furthermore, the target protection line, the target dynamic extended protection line, and the protection line after the shift all refer to the same technical object, namely the dynamic extended protection line in the embodiment; the preset voltage difference specifically refers to the execution parameter formed by the controlled difference between the static standby cutoff discharge threshold and the dynamic extended protection line under the above unified voltage dimension, rather than an arbitrary fixed constant that is independent of the safety lookup process.

[0158] Furthermore, the system also includes a composite switch execution module for performing switching actions in response to the main control relay cut-off command. The method includes: setting up a collaborative power supply bypass in the composite switch execution module, which consists of a bidirectional AC high-frequency solid-state static switch branch connected in parallel with a mechanical contact main switch circuit; when the main control relay cut-off command is received, controlling the mechanical contact main switch circuit to disconnect, so that the energy of the conductive load is instantly transferred and the bidirectional AC high-frequency solid-state static switch branch is turned on to maintain continuous flow; after a preset collision avoidance protection delay countdown time, disconnecting the conduction control command for the bidirectional AC high-frequency solid-state static switch branch, thereby achieving complete physical current interruption protection.

[0159] This embodiment provides a composite switching execution mechanism. Specifically, in the aforementioned scheme, even if the control logic can accurately determine when to cut off or switch, if the execution mechanism still adopts a single mechanical contact method, the railway communication signal load may still encounter a micro-hour gap interruption at the moment of switching. Especially when the message is continuously transmitted, the signal drive circuit or the high-frequency communication unit is powered, this short-term interruption may also cause the equipment to reset or the link to be rebuilt. Therefore, this embodiment introduces a composite execution structure of solid-state and mechanical parallel connection.

[0160] The specific processing procedure is as follows: The composite switch execution module is internally equipped with a bidirectional AC high-frequency solid-state static switch branch and a mechanical contact main switch circuit connected in parallel to form a collaborative power supply bypass. Under normal conditions, the mechanical main switch undertakes the main current path to obtain lower conduction losses. When a disconnection command is received, the system first controls the mechanical main switch circuit to disconnect, and at the same time immediately turns on the solid-state static switch branch, thereby smoothly transferring the load energy conduction path to the solid-state branch. The advantages of solid-state switches are fast response, no mechanical jump, and the ability to overcome the current continuity problem at the moment of mechanical contact separation.

[0161] Furthermore, in this embodiment, the composite switch execution module is located at the power supply switching node of the communication signal equipment in the backup power access station. This node can be the AC input side of the equipment, the AC distribution side after inverter output, or an equivalent switching branch that can withstand the AC bidirectional commutation process. The aforementioned battery cell sampling, charge / discharge determination, and relay control are still performed on the lithium iron phosphate backup battery system itself.

[0162] In other words, the bidirectional AC high-frequency solid-state static switch branch is used to solve the problem of continuous flow at the end of the equipment power supply switching, without changing the aforementioned monitoring and protection logic for lithium iron phosphate batteries. With this setting, the battery side is responsible for giving the cut-off or maintenance command, and the composite switch side is responsible for converting the command into a smoother execution action for the load in the station. The two are at different physical levels in the same system.

[0163] After the preset collision avoidance protection delay countdown ends, the conduction control of the solid-state branch is then canceled, causing it to finally shut down and complete the physical disconnection. The delay time is set here to avoid a time conflict between the solid-state and mechanical actions when the mechanical contacts have not completely left, the arc in the circuit has not dissipated, or the energy storage element in the load has not been released. By disconnecting the mechanical first, continuing the current in the solid-state, and then disconnecting the solid-state after a delay, both seamless transition and final hard isolation can be achieved.

[0164] Furthermore, if the implementation within the station uses a DC backup bus to directly supply power to downstream equipment, then the bidirectional AC high-frequency solid-state static switch branch can be arranged at the equipment-side switching node formed after the DC backup power supply is inverted or transformed; if the implementation within the station itself uses an AC backup power supply link, then this solid-state branch directly undertakes the transition current carrying function on the AC side; therefore, this embodiment emphasizes the relay timing and isolation effect of composite execution, rather than directly connecting the AC solid-state branch in series with the individual battery sampling circuit, thereby avoiding hierarchical confusion between the battery monitoring object and the switching execution object;

[0165] In a parallel switching process, the mechanical path can be regarded as the normal main current path and the solid path as the transitional conduction path. The disconnection action does not cut off the two paths at the same time. Instead, the transitional conduction path is established first, then the main current path is disconnected, and the transitional conduction path is removed after the circuit state is stable, so as to reduce the risk of power interruption at the moment of switching.

[0166] Furthermore, to avoid ambiguity caused by the instantaneous transfer of conducted load energy, in this embodiment, the statement refers to the transfer of the load current path from the mechanical contact main switch circuit to the bidirectional AC high-frequency solid-state static switch branch, and does not indicate that there is additional energy generation or storage on the load side; the corresponding controller prioritizes ensuring that the two branches meet the sequential constraints of first establishing freewheeling, then implementing mechanical separation, and finally performing solid-state shutdown in the switching transition sequence.

[0167] As an anomaly handling mechanism, if the solid-state branch fails to self-test or the conduction feedback is abnormal, the system will not perform a seamless crossing action, but will switch to mechanical single-circuit disconnection and simultaneously report a fault alarm for the transition branch; if the mechanical main switch does not disconnect as expected, the solid-state branch will remain on for a short time and trigger timeout diagnosis, and the upper-level system will intervene if necessary; if abnormal current is detected after the solid-state branch is turned off, entering the sleep state is prohibited, and the subsequent isolation verification process will be initiated.

[0168] In the aforementioned stations, when critical operations end and the system decides to disconnect the backup battery power supply, if the station's equipment uses the backup battery to provide AC power to the interlocking and communication equipment after conversion, the composite switch execution module first allows the AC solid-state branch to receive the instantaneous current, and then allows the mechanical main switch to disconnect the current flow, preventing the interlocking and communication equipment from resetting due to voltage collapse during switching. If the station's equipment uses a DC backup link, the solid-state branch can be set at the input switching node of the converted equipment, achieving the same effect of first continuing current and then isolating. After a preset protection time delay, the solid-state branch is completely turned off, so that the battery pack and the load side are truly isolated.

[0169] The purpose of this step is to eliminate the inherent short-term interruption blind zone of mechanical switches at the execution level of the cut-off action, thereby achieving smoother and more reliable power supply switching protection for railway communication signal loads.

[0170] Furthermore, to ensure consistency in terminology, the terms "solid-state static switch branch" and "solid-state branch" mentioned in this document correspond to the bidirectional AC high-frequency solid-state static switch branch in the embodiments, and the terms "mechanical main switch" and "mechanical main switch circuit" correspond to the mechanical contact main switch circuit in the embodiments. The differences are merely abbreviations and do not indicate the addition of other switching devices or changes in parallel topology.

[0171] Furthermore, in this embodiment, the switching action executed in response to the main control relay cut-off command means that the main control relay, as the upstream control determination device, outputs the cut-off command, and the composite switch execution module, as the downstream execution device, completes the two-stage action of continuous flow and final disconnection at the switching node on the equipment side. The main control relay itself does not replace the function of the bidirectional AC high-frequency solid-state static switch branch or the mechanical contact main switch circuit. Therefore, the battery-side determination link and the equipment-side execution link are allowed to be set up in layers in terms of physical location, but they are kept to be uniformly coordinated by the same controller in terms of control timing, so as to avoid the main control relay, the mechanical contact main switch circuit and the bidirectional AC high-frequency solid-state static switch branch being mistakenly named as duplicates of the same level.

[0172] Furthermore, the system is also equipped with an isolation verification self-check program module to prevent disconnection failure, which is used to execute: when the main control relay disconnection command is issued according to the static standby cutoff discharge threshold, or after the target service is confirmed to be processed and the corresponding main control relay disconnection command is issued, the static end voltage detection measurement channel connected to the load terminal output side is activated.

[0173] Measure and obtain the residual static voltage interference value generated by the parallel capacitor feedback, and compare the residual static voltage interference value with the preset safety isolation measurement threshold value;

[0174] If the residual static voltage interference value is found to be greater than the preset safety isolation measurement threshold, a low-level physical fault prompt indicating feedback cut-off failure is generated and uploaded to the monitoring center.

[0175] If the residual static voltage interference value is less than or equal to the preset safety isolation measurement threshold, the disconnection state is marked as valid and the system enters the no-power-consumption protection sleep mode.

[0176] This embodiment provides a self-checking mechanism for isolation verification after disconnection. Specifically, after the aforementioned composite switch execution module completes the disconnection action, if it is determined that the circuit has been disconnected based solely on the issuance of control commands or changes in switch feedback, there are still potential risks. This is because the load side in the field often has parallel-connected filter capacitors, surge suppressors, or other energy storage components, and residual voltage may cause misjudgment. On the other hand, if the contacts are stuck, solid-state devices are broken down, or the bypass branch is abnormal, the control level shows that the circuit has been disconnected, but there may still be electrical discharge or connection.

[0177] The specific processing procedure is as follows: after the system cuts off the load according to the static cutoff threshold or after the core business is completed, the isolation verification self-check program immediately activates the static terminal voltage detection measurement channel on the output side of the load terminal; this measurement channel is not used to observe the operating voltage under load, but to detect whether there is still an abnormal residual static terminal voltage on the load side after the load is cut off.

[0178] The static terminal voltage detection measurement channel includes a high-impedance voltage divider resistor network and an opto-isolation amplifier connected in series in the electrical structure. It is used to convert the residual AC or DC signal on the high-voltage side into a low-voltage measurement signal and feed it back to the controller without destroying the original electrical isolation characteristics of the load side.

[0179] The system measures the residual static voltage interference value generated by the feedback of the parallel capacitor and compares it with the preset safety isolation measurement threshold. The engineering meaning of this comparison is that after normal disconnection, there may be residual charge on the load side for a short time, which is a phenomenon of natural discharge of energy storage elements. However, this residual charge should decay to below the safety threshold. If the measured residual static voltage is continuously greater than the threshold, it indicates that there may be disconnection failure, incomplete contact separation, solid-state branch leakage, feedback loop interference, or other underlying physical faults.

[0180] The system generates a disconnection failure prompt and uploads it to the monitoring center. If the residual static voltage is not higher than the safety threshold, the disconnection is marked as valid, allowing the system to enter a power-free protection sleep mode to reduce subsequent self-consumption. In the simplified test model, the state of the load side after disconnection can be understood as two types: one is that there is only residual capacitor charge, which will decay naturally; the other is that there is still a source of power supply or an abnormal path, and the voltage fails to decay to below the preset threshold. The safety isolation measurement threshold is the boundary used to distinguish between these two types of states.

[0181] As an anomaly handling mechanism, if the measurement channel itself fails to perform a self-test, the system will not directly determine that the disconnection is effective, but will maintain the alarm observation state and request remote verification; if the residual static voltage measured for the first time is slightly higher than the threshold, but shows a continuous downward trend, the system can repeat the measurement after a short wait to prevent the normal discharge of the capacitor from being mistakenly judged as a disconnection failure; if the voltage is still higher than the threshold after repeated measurement, it will be treated as a disconnection failure; if the communication with the monitoring center is interrupted, the system should also save the fault record locally and prohibit entering sleep mode so that subsequent maintenance personnel can read it on-site.

[0182] At the same station, after the train passes safely, the system disconnects the backup battery power supply according to the established strategy. After the disconnection is completed, a certain static voltage can still be measured on the load terminal side. The system observes through the detection measurement channel whether the voltage is only caused by the release of the filter capacitor. If it quickly decays to below the safety threshold, the disconnection is considered effective and the system enters a low-power waiting state. If the voltage remains at a high level for a long time, the system determines that there may be contactor sticking or solid branch leakage, and immediately generates a low-level physical fault prompt and uploads it to the monitoring center.

[0183] The purpose of this step is to further verify that the control has been disconnected as if it were truly isolated electrically, thereby achieving a closed-loop self-check of the failure at the execution end and preventing hidden safety risks from being left by the backup power supply when it should have been disconnected.

[0184] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A monitoring and dynamic switching system for intelligent lithium iron phosphate backup power supply for railway communication signals, characterized in that, This system is connected in series between the system power supply main circuit and the backup battery system, and includes at least a main control relay, a power sensor, and a controller connected to the main control relay and the power sensor. The controller is configured to implement the following modules: The parameter acquisition module is used to acquire real-time individual cell voltage data, real-time total voltage change rate, charging and discharging current data, and real-time communication load operating load of the backup battery system, and to extract the pre-stored static backup cutoff discharge threshold and preset polarization warning line of the system. The polarization detection and identification module is used to trigger the current drop detection mechanism to obtain transient voltage drop data during charging, and to perform charging mode switching or output a main control relay cut-off command based on the comparison result of the transient voltage drop data and the preset polarization warning line. The anti-jitter locking module is used to control the main control relay to disconnect in response to the main control relay disconnect command, and to control the main control relay to be in an inactive state based on the current disconnection duration and the real-time individual voltage data. The voltage drop risk prediction module is used to calculate the voltage drop characteristic value based on the real-time total voltage change rate during discharge, and to calculate the standby working margin time in real time. The dynamic power distribution module is used to dynamically adjust the protection baseline or output the main control relay disconnection command based on the standby working margin time, the preset critical depletion threshold time, and the real-time communication load operation load.

2. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, The specific logic of the polarization detection and discrimination module, the anti-jitter locking module, and the dynamic power distribution module is as follows: The polarization detection and discrimination module acquires a preset cell protection voltage and limits the charging and discharging current data when the real-time cell voltage data is greater than or equal to the preset cell protection voltage. If the transient fall-off voltage data is less than the preset polarization warning line, then switch to the predetermined pulse equalization charging mode; if it is greater than or equal to the preset polarization warning line, then confirm full charging and output the main control relay cut-off command. The anti-shake locking module releases the engagement prohibition state to allow subsequent charging when the current separation duration is greater than or equal to a preset locking time threshold and the real-time individual voltage data is lower than a preset charging allowable voltage threshold; otherwise, it maintains the locking state that controls the main control relay to disengage. The dynamic power distribution module maintains normal power supply to the backup battery system when the backup working margin time is greater than the preset critical depletion threshold time. When the backup working margin time is less than or equal to the preset critical depletion threshold time and a core business activity indicator is identified, the static backup cutoff discharge threshold is subtracted from the preset voltage difference to generate a dynamic extended protection bottom line, and the main control relay is forced to remain closed until the business processing is completed. If the core business activity identifier does not exist and the real-time unit voltage data is less than or equal to the static standby cutoff discharge threshold, output the main control relay disconnection command.

3. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, The specific operations by which the parameter acquisition module obtains the real-time total voltage change rate include: High-frequency sampling is performed on the battery terminals of the backup battery system to obtain discrete voltage time series; A sliding window smoothing filter is applied to the discrete voltage time series to remove instantaneous interference voltage data and generate a smooth voltage curve; Obtain the slope feature vector of the smoothed voltage curve within the previous monitoring time interval at the current time point; The absolute value of the slope feature vector is taken and the time-distance weighted average is calculated to obtain the real-time total voltage change rate.

4. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, The system also includes a built-in intelligent power module. The specific operations of the polarization detection and discrimination module in triggering the current sag detection mechanism and acquiring transient fall-off voltage data include: When the real-time individual cell voltage data reaches the preset individual cell protection voltage, the intelligent power module reduces the charging current value to the preset test current reference. After a preset test delay period, the real-time tracking terminal voltage value of the backup battery system response is obtained; The absolute difference between the real-time individual voltage data and the real-time tracking terminal voltage value is calculated, and the difference is corrected by combining the pre-stored temperature compensation coefficient to generate the corrected voltage drop amount. The corrected voltage drop is output as the transient voltage drop data.

5. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 2, characterized in that, The specific operations of the polarization detection and discrimination module in executing the predetermined pulse equalization mode include: The pulse width modulation signal generation link inside the system is activated, and a timing pulse signal with a preset interval time is output. According to the timing pulse signal, the charging power module configured inside the driving system intermittently injects a limiting current into the backup battery system. During the predetermined interval when the current injection is stopped, the terminal voltage data of each cell is collected synchronously, and a static cell terminal voltage data matrix is ​​constructed according to the continuous sampling period and the cell arrangement dimension. When all values ​​in the static single-unit terminal voltage data matrix acquired within a consecutive preset acquisition period are greater than or equal to the preset polarization warning line, the current pulse equalization charging control process is terminated, and the main control relay cut-off command is generated; when there is a value in the static single-unit terminal voltage data matrix that is less than the preset polarization warning line, the current pulse equalization charging mode continues to be executed.

6. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 2, characterized in that, The method by which the anti-jitter locking module, in conjunction with a state countdown timer, maintains the unlocked state of the main control relay includes: After obtaining the drive signal disconnection flag associated with the main control relay disconnection action, start the status countdown timer to count the separation duration; Real-time acquisition of external ambient temperature data and battery body temperature data; by querying a preset temperature difference and bias time mapping table, or by executing a proportional-integral adjustment function, the temperature compensation bias time is calculated and generated based on the difference between the external ambient temperature data and the battery body temperature data. The preset locking time threshold is dynamically adjusted by superimposing the temperature compensation bias time to obtain the corrected locking determination time requirement. If the current separation duration is less than the modified lockout determination time requirement, regardless of whether the real-time individual voltage data is lower than the preset charging allowable voltage threshold, the closing control command to the main control relay will be blocked to maintain the unlocked state.

7. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, Methods for real-time calculation of standby working margin time include: Retrieve the pre-stored smooth terminal inflection point voltage data of the discharge characteristics of the lithium iron phosphate material corresponding to the backup battery system. Obtain the current overall total output terminal voltage of the backup battery system, and calculate the current available voltage difference between the current overall total output terminal voltage and the terminal voltage data at the smooth terminal inflection point; Extract the voltage drop feature value sequence with the timestamp closest to the current time and a preset number of consecutive times, and establish a quadratic prediction polynomial with time as the independent variable and voltage drop magnitude as the dependent variable; The current available voltage difference is substituted into the quadratic prediction polynomial as the dependent variable to solve for the independent variable, and the positive real roots are extracted as the corresponding time span values ​​to obtain the final standby working margin time.

8. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 2, characterized in that, Methods for generating a dynamic extended protection baseline by subtracting a preset voltage difference from the static standby cutoff discharge threshold include: The real-time communication load is subjected to communication protocol identification and capture, and interlocking data packets including route occupancy instructions, beacon response messages and collision avoidance control messages are extracted. When any of the above interlocking data packets is identified as being in an active process state, the protection mode flag is triggered as an indicator of the presence of active core business. After the protection mode flag is triggered, the pre-configured battery cell safe discharge data table is called to map and extract the deepest discharge voltage lower limit warning value that will not induce battery safety hazards. The dynamic extended protection baseline is generated by adding the deepest discharge voltage lower limit warning value to the preset backup safety voltage value required for the basic operation of the equipment, and then replacing the original protection limit.

9. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, The system also includes a composite switch execution module for performing switching actions in response to a main control relay cut-off command, the method of which includes: The composite switch execution module is equipped with a collaborative power supply bypass consisting of a bidirectional AC high-frequency solid-state static switch branch connected in parallel with a mechanical contact main switch circuit. When the main control relay is disconnected, the mechanical contact main switch circuit is disconnected, so that the energy of the conductive load is transferred instantly and the bidirectional AC high-frequency solid-state static switch branch is turned on to maintain continuous flow. After a preset collision avoidance protection delay countdown time, the conduction control command for the bidirectional AC high-frequency solid-state static switch branch is disconnected, thereby achieving complete physical current interruption protection.

10. The intelligent lithium iron phosphate backup power monitoring and dynamic switching system for railway communication signals according to claim 1, characterized in that, The system is also equipped with an isolation verification self-check module to prevent resection failure, which is used to perform: When the main control relay is disconnected according to the static standby cutoff discharge threshold, or when the target service is confirmed to be completed and the corresponding main control relay is disconnected, the static end voltage detection measurement channel connected to the output side of the load terminal is activated. Measure and obtain the residual static voltage interference value generated by the parallel capacitor feedback, and compare the residual static voltage interference value with the preset safety isolation measurement threshold value; If the residual static voltage interference value is diagnosed as being greater than the preset safety isolation measurement threshold, a low-level physical fault prompt indicating feedback cut-off failure is generated and uploaded to the monitoring center. If the residual static voltage interference value is less than or equal to the preset safety isolation measurement threshold, the disconnection state is marked as valid and the system enters a power-free protection sleep mode.

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