A circuit breaker protection detection module fault detection method and system

Abstract

The application provides a circuit breaker protection detection module fault detection method and system, applied to the technical field of circuit breakers, through not simply triggering under-voltage protection when the cumulative under-voltage time reaches a preset delay value, but further judging whether the duration of a voltage drop in the continuous monitoring time period truly exceeds the preset under-voltage state confirmation delay setting value. If not, a "timing logic error report" is sent instead of an irregular under-voltage fault report. Through the scheme, the technician can clearly identify whether it is a timing logic problem or an actual under-voltage fault when checking the fault recording data afterwards, greatly improving the accuracy and efficiency of fault diagnosis, overcoming the defect that the misoperation is difficult to locate in the prior art, and thus significantly improving the reliability of the circuit breaker protection detection module and the operation stability of the system.

Description

Technical Field

[0001] This application relates to the technical field, and in particular to a fault detection method and system for a circuit breaker protection detection module. Background Technology

[0002] In industrial production, circuit breaker protection and detection modules are a crucial component for ensuring the safe operation of electrical equipment, and they typically include undervoltage protection. To avoid malfunctions caused by transient voltage fluctuations, these modules generally employ a "delayed confirmation" mechanism, meaning that protection is only triggered if the low voltage condition persists for a preset time. However, in practical applications, especially on automated production lines that prioritize high efficiency, the optimization of equipment start-up and shutdown modes can lead to a unique voltage fluctuation pattern in the power grid: the voltage repeatedly crosses the undervoltage threshold at a high frequency and with low amplitude.

[0003] At this point, the module incorporates a "state stabilization period" judgment logic to enhance anti-interference capabilities. When the voltage recovers from below the undervoltage threshold to above it, the undervoltage timer pauses and waits for the voltage to stabilize above the threshold for a preset stabilization time before resetting to zero. This design aims to improve logic stability. However, if the time it takes for the voltage to recover above the threshold is very short and fails to reach the preset stabilization time, the undervoltage timer will not be reset to zero. In this case, if the voltage subsequently drops below the undervoltage threshold again, the protection logic will continue to accumulate from the value at which the undervoltage timer was currently paused.

[0004] This cyclical pattern of "voltage drop-timing-brief recovery-timing pause-flip-resuming-timing" may repeatedly occur under the specific power grid fluctuation environment described above. Although the duration of each individual voltage drop is much shorter than the undervoltage judgment delay setting, the cumulative total time may unexpectedly exceed the undervoltage judgment delay setting because the undervoltage timer is not effectively reset between multiple short drops. This ultimately leads to a malfunction in the circuit breaker protection detection module, causing a production interruption. When technicians subsequently review the fault recording data, they will find that the duration of any single voltage drop event does not meet the undervoltage protection's operating conditions, making this malfunction difficult to diagnose and locate using conventional methods.

[0005] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0006] In view of the shortcomings of the prior art, this application provides a fault detection method and system for circuit breaker protection detection modules, which aims to solve the problem that existing circuit breaker protection detection modules malfunction due to the failure to effectively clear the accumulated time of the undervoltage timer under specific power grid voltage fluctuation environments, and that it is difficult to diagnose the problem.

[0007] In a first aspect, a fault detection method for a circuit breaker protection detection module, the method comprising the following steps:

[0008] S1: Continuously monitor the voltage of the power grid. When the voltage is lower than the preset threshold, start the main undervoltage timer to accumulate the undervoltage time when the voltage drops.

[0009] S2: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery;

[0010] S3: If the accumulated stable voltage time reaches the preset stable time, the undervoltage time is reset to zero; if the stable voltage time does not reach the preset stable time and the voltage is lower than the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time.

[0011] S4: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, determine whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, send a regular undervoltage fault report; otherwise, send a timing logic error report.

[0012] This application proposes a fault detection method for a circuit breaker protection detection module. By comparing the accumulated undervoltage time with the duration of a single continuous voltage drop, it can effectively distinguish between genuine undervoltage faults and timer logic errors caused by high-frequency, low-amplitude voltage fluctuations. This directly solves the malfunction and diagnostic problems described in the background art, significantly improving the reliability and diagnostic accuracy of the circuit breaker protection detection module.

[0013] Furthermore, in step S4, the step of sending a timing logic error report if it does not exist includes the following steps:

[0014] S41: If not, determine whether there are multiple instances during the continuous monitoring period where the voltage recovers from below the undervoltage threshold to above the undervoltage threshold and the stabilization time does not reach the preset stabilization time.

[0015] S42: If not present, send a timing sampling or reset error report;

[0016] S43: If present, send a timing logic error report.

[0017] The circuit breaker protection detection module fault detection method proposed in this application refines the timing logic error report, which can further distinguish whether the error is due to a logic error caused by multiple brief recoverys that prevent the timer from being cleared, or a deeper error in the timing sampling or clearing mechanism itself, thereby providing more accurate fault diagnosis information.

[0018] Furthermore, step S1 includes:

[0019] S11: Continuously monitor the voltage of the power grid. When the voltage is lower than the preset threshold value for the first time, start the confirmation timer to accumulate the confirmation undervoltage time.

[0020] S12: When the confirmation undervoltage time reaches the preset confirmation duration and the voltage remains below the preset threshold, the main undervoltage timer is started to accumulate the undervoltage time;

[0021] S13: If the confirmation undervoltage time does not reach the preset confirmation duration and the voltage recovers to a value exceeding the preset threshold, then the confirmation timer is reset.

[0022] The fault detection method for circuit breaker protection detection module proposed in this application introduces an acknowledgment timer before starting the main undervoltage timer, which effectively filters out instantaneous or extremely short voltage drops, avoids unnecessary starting and accumulation of the main undervoltage timer, and thus improves the anti-interference capability and stability of the initial undervoltage detection.

[0023] Furthermore, step S2 includes:

[0024] S21: When the voltage recovers to a value exceeding the preset threshold, obtain the current operating mode of the circuit breaker protection detection module;

[0025] S22: Select the corresponding stable timer startup strategy according to the current operating mode; the stable timer startup strategy includes:

[0026] In system startup mode, the stabilization timer starts after a preset time delay following voltage recovery;

[0027] In load switching mode, the stabilization timer is activated based on the sensitivity corresponding to the voltage recovery amplitude;

[0028] S23: Pause the main undervoltage timer and start the stabilization timer according to the selected stabilization timer start strategy to accumulate the stabilization voltage time.

[0029] This application proposes a fault detection method for a circuit breaker protection detection module. The startup strategy of the stabilization timer can be adaptively adjusted according to the current operating mode of the circuit breaker protection detection module. For example, different startup logics are adopted in different scenarios such as system startup or load switching, thereby optimizing the responsiveness and accuracy of the stabilization timer and further improving the overall adaptability of the system.

[0030] Furthermore, in step S22, the step of starting the stabilization timer according to the sensitivity corresponding to the voltage recovery amplitude in the load switching mode includes the following steps:

[0031] S221: Preset multiple voltage recovery amplitude threshold ranges and configure the corresponding stable timer start sensitivity for each threshold range;

[0032] S222: Real-time detection of the voltage recovery amplitude;

[0033] S223: Determine the threshold range to which the voltage recovery amplitude belongs based on the voltage recovery amplitude;

[0034] S224: Start the stabilization timer according to the sensitivity corresponding to the threshold range.

[0035] Furthermore, step S23 includes:

[0036] S231: Pause the main undervoltage timer and generate a timing start signal, which is used to trigger the interrupt service routine;

[0037] S232: In the interrupt service routine, the stable timer is started according to the selected stable timer start strategy;

[0038] S233: The stabilization timer uses periodic timing interrupts to accumulate the stabilization voltage time.

[0039] Furthermore, step S3 includes:

[0040] S31: Obtain the depth information of the voltage drop, the depth information including the maximum deviation value of the voltage from the preset threshold value during the voltage drop;

[0041] S32: Obtain frequency information of voltage crossing threshold within a preset analysis time window, wherein the frequency information includes the number of times the voltage recovers from below the preset threshold value to above the preset threshold value within the preset analysis time window;

[0042] S33: Determine the preset stabilization time based on the maximum deviation value and the number of times the threshold is crossed;

[0043] S34: If the accumulated stable voltage time reaches the preset stable time, then the undervoltage time is cleared to zero;

[0044] S35: If the voltage stabilization time does not reach the preset stabilization time and the voltage falls below the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time.

[0045] Furthermore, step S32 includes:

[0046] S321: When the maximum deviation value is less than the first preset deviation threshold and the number of times the threshold is crossed is greater than the first preset frequency threshold, the preset stabilization time is set to the first stabilization time value.

[0047] S322: When the maximum deviation value is greater than the second preset deviation threshold and the number of times the threshold is crossed is less than the second preset frequency threshold, the preset stabilization time is set to the second stabilization time value.

[0048] The first settling time value is less than the second settling time value.

[0049] Furthermore, step S4 includes:

[0050] S44: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, during the continuous monitoring period, record the duration of each consecutive drop event in which the voltage drops from above the preset threshold value to below the preset threshold value and remains below the preset threshold value until it recovers to above the preset threshold value again.

[0051] S45: Determine whether any of the recorded single consecutive drop events has a drop duration exceeding the preset undervoltage state confirmation delay setting value.

[0052] S46: If present, send a standard undervoltage fault report;

[0053] S47: If not present, send a timing logic error report.

[0054] Secondly, a circuit breaker protection detection module fault detection system is provided for implementing the method described in any of the above claims, the system comprising:

[0055] First timing module: continuously monitors the voltage of the power grid. When the voltage is lower than a preset threshold, the main undervoltage timer is started to accumulate the undervoltage time during the voltage drop.

[0056] Second timing module: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery;

[0057] Third timing module: If the accumulated stable voltage time reaches the preset stable time, the undervoltage time is cleared to zero; if the stable voltage time does not reach the preset stable time and the voltage is lower than the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time.

[0058] Fault detection module: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, it determines whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, a regular undervoltage fault report is sent; otherwise, a timing logic error report is sent.

[0059] Beneficial Effects: This application proposes a fault detection method and system for circuit breaker protection detection modules. By introducing a comparison and judgment mechanism between the accumulated undervoltage time and the duration of a single continuous voltage drop, it effectively solves the technical problem in the prior art where the high-frequency, low-amplitude repeated crossings of the grid voltage near the undervoltage threshold cause the undervoltage timer to fail to be effectively cleared, leading to malfunctions of the circuit breaker protection detection module that are difficult to diagnose. Specifically, when the accumulated undervoltage time reaches a preset delay value, this method does not simply trigger undervoltage protection, but further determines whether there is a voltage drop duration that truly exceeds the preset undervoltage state confirmation delay setting within the continuous monitoring period. If not, a "timing logic error report" is explicitly sent, instead of a conventional undervoltage fault report. Accordingly, this application can accurately distinguish between timer accumulation errors caused by instantaneous or high-frequency fluctuations and real long-term undervoltage events, avoiding unnecessary production interruptions. This solution enables technicians to clearly identify timing logic problems rather than actual undervoltage faults when reviewing fault recording data after an incident. This greatly improves the accuracy and efficiency of fault diagnosis, overcomes the shortcomings of existing technologies in locating malfunctions, and significantly enhances the reliability of the circuit breaker protection detection module and the operational stability of the system. Attached Figure Description

[0060] Figure 1 This is a flowchart of a fault detection method for a circuit breaker protection detection module proposed in this application.

[0061] Figure 2 This is a structural diagram of a fault detection system for a circuit breaker protection detection module proposed in this application.

[0062] Figure 3 This is an architecture diagram of a fault detection system for a circuit breaker protection detection module proposed in this application.

[0063] Labeling explanation: 201, First timing module; 202, Second timing module; 203, Third timing module; 204, Fault detection module. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0065] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0066] Please refer to Figure 1 A fault detection method for a circuit breaker protection detection module, the method comprising the following steps:

[0067] S1: Continuously monitor the voltage of the power grid. When the voltage is lower than the preset threshold, start the main undervoltage timer to accumulate the undervoltage time when the voltage drops.

[0068] S2: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery;

[0069] S3: If the voltage stabilization time reaches the preset stabilization time, the undervoltage time will be reset to zero; if the voltage stabilization time does not reach the preset stabilization time and the voltage falls below the preset threshold again, the main undervoltage timer will be started to continue accumulating the undervoltage time.

[0070] S4: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, determine whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, send a regular undervoltage fault report; otherwise, send a timing logic error report.

[0071] In this context, the voltage of the power grid refers to the voltage value transmitted in the power system, and its stability directly affects the normal operation of electrical equipment. The preset threshold value is a voltage threshold set to determine whether the voltage is in an undervoltage state. When the actual voltage is lower than this threshold value, it is considered an undervoltage state.

[0072] The main undervoltage timer is a timing unit used to accumulate the duration of an undervoltage state. When the voltage drops below a preset threshold, the timer is activated and begins accumulating the undervoltage time. The stabilization timer, on the other hand, accumulates the time the voltage remains stable above a preset threshold after recovering from the undervoltage state. Its purpose is to ensure the stability of voltage recovery and avoid misjudgments caused by instantaneous recovery.

[0073] The preset stabilization time refers to the length of time that the voltage needs to remain above a preset threshold after recovering from an undervoltage state. Only when the stabilization time reaches this preset value is the voltage considered to have stabilized and recovered, at which point the undervoltage time is reset to zero. The preset undervoltage state confirmation delay setting is a key threshold for determining whether a real undervoltage fault has occurred. When the accumulated undervoltage time reaches this setting value, the system will perform further fault assessment.

[0074] A standard undervoltage fault report is issued when the system determines that an undervoltage fault is genuine, and it usually triggers corresponding protection actions. A timing logic error report, on the other hand, is issued when the system determines that the accumulated undervoltage time has reached a threshold, but no sustained undervoltage fault has actually occurred. This indicates a possible anomaly in the timing logic, requiring further investigation.

[0075] The fault detection method for circuit breaker protection detection module disclosed in this application aims to solve the problem in the prior art of undervoltage protection malfunction caused by high-frequency voltage fluctuations and the difficulty in diagnosis.

[0076] First, in step S1, an analog-to-digital converter (ADC) can be used to sample the grid voltage in real time and compare the sampled values ​​with a preset threshold. For example, a fixed sampling frequency can be set, such as sampling the voltage value once every millisecond. When multiple consecutive sampling points show that the voltage is lower than the preset threshold, a voltage drop can be determined. At this time, the main undervoltage timer is activated and starts timing. This timer can be a software counter, which accumulates through a system clock interrupt or a hardware timer. As a preferred implementation, a simple voltage comparator can be set up. When the input voltage signal is lower than a preset reference voltage, it outputs a low-level signal, which is received by the microcontroller and triggers the start of the main undervoltage timer.

[0077] Secondly, in step S2, this operation can be triggered by a voltage rising edge detection circuit. When a voltage transition from a low level to a high level (i.e., exceeding a preset threshold) is detected, the main undervoltage timer is paused and the stabilization timer is started. The stabilization timer can also be a software counter or a hardware timer, and its timing accuracy can be configured according to actual needs.

[0078] Furthermore, in step S3, if the voltage stabilization time reaches the preset stabilization time, it indicates that the voltage has stabilized and recovered. At this point, the accumulated undervoltage time in the main undervoltage timer will be reset to zero. This ensures that the system can restart the accumulation of undervoltage time after the voltage truly stabilizes, avoiding interference from historical undervoltage time in subsequent judgments. However, if the voltage stabilization time fails to reach the preset stabilization time, and the voltage drops below the preset threshold again, the main undervoltage timer will resume accumulating undervoltage time from its paused value. This logic design effectively addresses scenarios where the voltage repeatedly crosses the threshold at high frequency and low amplitude, ensuring continuous accumulation of undervoltage time under unstable recovery conditions and preventing the undervoltage time from being incorrectly reset to zero due to multiple brief recovery cycles.

[0079] Finally, in step S4, by determining whether there is a voltage drop during the continuous monitoring period whose duration exceeds a preset undervoltage state confirmation delay value, the system can distinguish between two different situations: one is a genuine undervoltage fault with a sufficiently long duration, in which case a regular undervoltage fault report is sent; the other is a "timing logic error" caused by high-frequency voltage fluctuations leading to accumulated undervoltage time, but where the actual duration of each drop is insufficient to trigger the protection, in which case a timing logic error report is sent. Therefore, the overall solution of this application can accurately identify the fault type, avoid malfunctions that occur under specific fluctuation environments using traditional methods, and provide technicians with more accurate fault diagnosis information.

[0080] The core innovation of the circuit breaker protection detection module fault detection method proposed in this application lies in the fundamental improvement of the judgment logic for undervoltage faults, especially in the special scenario of dealing with high-frequency, low-amplitude repeated voltage crossings of the power grid, which shows significant technological progress.

[0081] Traditional undervoltage protection mechanisms typically rely on a "delayed confirmation" logic, where protection is triggered when the accumulated low voltage time reaches a preset threshold. However, as described in the background section, this mechanism is problematic when the voltage repeatedly crosses the undervoltage threshold at high frequency and low amplitude. Because the undervoltage timer is not effectively reset between multiple short drops, the accumulated time may unexpectedly exceed the undervoltage determination delay setting, leading to a false undervoltage protection operation by the circuit breaker's protection detection module. More seriously, subsequent review of fault recording data reveals that the duration of any single voltage drop event does not meet the undervoltage protection's operating conditions, making such false operations difficult to diagnose and locate using conventional methods.

[0082] In contrast, the method of this application introduces a key judgment logic in step S4: when the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, instead of directly sending a fault report, it further judges whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. This additional judgment step is the innovation of this application.

[0083] In some embodiments of this application, when the accumulated undervoltage time reaches a preset undervoltage state confirmation delay setting, and there is no voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting, a timing logic error report is sent. However, such a single error report may not accurately distinguish between different types of timing logic anomalies, thus affecting the efficiency and accuracy of fault diagnosis.

[0084] In this regard, this application further proposes that, in step S4, if the error does not exist, sending a timing logic error report includes the following steps:

[0085] S41: If not, determine whether there are multiple instances during the continuous monitoring period where the voltage recovers from below the undervoltage threshold to above the undervoltage threshold and the stabilization time does not reach the preset stabilization time.

[0086] S42: If not present, send a timing sampling or reset error report;

[0087] S43: If present, send a timing logic error report.

[0088] Specifically, if the result of the above determination that there is no voltage drop exceeding the preset undervoltage state confirmation delay value during the continuous monitoring period is "no", the system will no longer directly send a unified timing logic error report. Instead, it will further execute step S41, which determines whether there are multiple instances during the continuous monitoring period where the voltage recovers from below the undervoltage threshold to above the undervoltage threshold, and the stabilization time does not reach the preset stabilization time. Here, "multiple times" means that during the continuous monitoring period, the voltage fluctuates repeatedly around the undervoltage threshold, and the time to recover to normal voltage each time is insufficient to meet the stabilization time requirement.

[0089] If the judgment result of step S41 is "not found," meaning that during the continuous monitoring period, neither a single long voltage drop nor multiple short-term voltage recovery instability situations were found, the system will send a timing sampling or clearing error report. This usually means that the timer may have encountered an anomaly when sampling data or performing a clearing operation, such as an unstable clock source of the timer itself, inaccurate sampling frequency, or the clearing command not being executed correctly.

[0090] Conversely, if the judgment result of step S41 is "existing," meaning that during the continuous monitoring period, although there was no single long voltage drop, there were multiple instances of unstable voltage recovery (the stabilization time did not reach the preset stabilization time), the system will send a timing logic error report. This indicates that there may be a problem with the timer's logic judgment or state transition. For example, the stabilization timer may not have started correctly after voltage recovery, or the stabilization timer may not have been paused correctly and the undervoltage time may have continued to accumulate when the voltage drops again, causing the timing logic to fail to perform as expected.

[0091] The above technical solution significantly improves the accuracy and efficiency of fault diagnosis in circuit breaker protection detection modules. Compared to sending only a single timing logic error report, this application can distinguish between timing sampling or resetting errors and timing logic errors based on specific abnormal patterns, thereby providing maintenance personnel with more instructive fault information, reducing troubleshooting time, and avoiding unnecessary maintenance operations.

[0092] Furthermore, step S1 includes:

[0093] S11: Continuously monitor the voltage of the power grid. When the voltage drops below the preset threshold for the first time, start the confirmation timer to accumulate the confirmation undervoltage time.

[0094] S12: When the undervoltage confirmation time reaches the preset confirmation duration and the voltage remains below the preset threshold, start the main undervoltage timer to accumulate the undervoltage time;

[0095] S13: If the undervoltage confirmation time does not reach the preset confirmation duration and the voltage recovers to a value exceeding the preset threshold, the confirmation timer is reset.

[0096] This application's solution effectively solves the misjudgment problem that may occur if the main undervoltage timer is started directly by introducing an acknowledgment timer and a preset acknowledgment duration before starting the main undervoltage timer. Specifically, when the voltage drops for the first time, the main undervoltage timer is not started immediately; instead, the acknowledgment timer is started first. The main undervoltage timer is only started when the voltage remains below a preset threshold and the accumulated acknowledgment undervoltage time of the acknowledgment timer reaches the preset acknowledgment duration. This mechanism ensures that only persistent undervoltage events that have been acknowledged for a certain period of time are recorded, thereby filtering out common instantaneous voltage fluctuations or brief drops in the power grid and avoiding unnecessary timing and subsequent fault reports triggered by instantaneous events.

[0097] In some implementations of the above method, a stabilization timer is activated to accumulate stabilization time when the voltage recovers to above a preset threshold. However, in practical applications, the recovery of grid voltage may occur under different system operating modes, such as system startup mode or load switching mode. In these modes, the voltage recovery characteristics may differ from those in normal operating mode. If the stabilization timer employs a single activation strategy, it may lead to inaccurate timing, thereby affecting the fault diagnosis accuracy and reliability of the circuit breaker protection detection module.

[0098] In this regard, this application further proposes that step S2 includes:

[0099] S21: When the voltage recovers to a value exceeding the preset threshold, obtain the current operating mode of the circuit breaker protection detection module;

[0100] S22: Select the corresponding stable timer startup strategy based on the current operating mode; stable timer startup strategies include:

[0101] In system startup mode, the stabilization timer starts after a preset delay following voltage recovery;

[0102] In load switching mode, the stabilization timer starts based on the sensitivity corresponding to the voltage recovery amplitude;

[0103] S23: Pause the main undervoltage timer and start the stabilization timer according to the selected stabilization timer start strategy to accumulate stabilization time.

[0104] Specifically, in step S21, the current operating state of the system is determined by reading the system's internal status register, receiving mode switching signals from the host computer or control unit, or making a judgment based on historical system operating data. For example, the system startup mode refers to the initial stage when the circuit breaker protection detection module is first powered on or wakes up from a dormant state; the load switching mode refers to the system performing high-power load connection or disconnection operations, which may cause transient voltage fluctuations.

[0105] In step S22, in system startup mode, the stabilization timer starts after a preset delay following voltage recovery. This is to allow the transient fluctuations experienced by the system voltage during the initial startup phase to fully stabilize, preventing premature or erroneous startup of the stabilization timer due to normal voltage fluctuations during startup, thus ensuring that the accumulated stabilization time is based on the true stable state. This preset time can be set according to system startup characteristics and empirical values. In load switching mode, the stabilization timer starts based on the sensitivity corresponding to the voltage recovery amplitude. This is to account for the varying degrees of voltage drop and recovery that load switching may cause. By adjusting the startup sensitivity, the authenticity of voltage recovery can be more accurately identified, avoiding misjudging normal voltage fluctuations caused by load switching as fault recovery, or delaying fault diagnosis due to insufficient sensitivity.

[0106] In step S23, pausing the main undervoltage timer ensures that undervoltage time will no longer accumulate after voltage recovery. Starting the stabilization timer according to the selected stabilization timer startup strategy ensures that the accumulation of stabilization time is based on the optimization strategy of the current system operating mode.

[0107] Through the above technical solution, the fault detection method of the circuit breaker protection detection module can more accurately and robustly determine the grid voltage status. This solution can effectively avoid the problem of erroneous starting or inaccurate timing of the stability timer caused by voltage transient fluctuations under special operating conditions such as system startup or load switching, thereby significantly reducing the false alarm rate and missed alarm rate, and improving the overall performance and reliability of the circuit breaker protection detection module.

[0108] Furthermore, in step S22, in load switching mode, the stabilization timer is activated based on the sensitivity corresponding to the voltage recovery amplitude, including the following steps:

[0109] S221: Preset multiple voltage recovery amplitude threshold ranges and configure the corresponding stable timer start sensitivity for each threshold range;

[0110] S222: Real-time detection of voltage recovery amplitude;

[0111] S223: Determine the threshold range to which the voltage recovery amplitude belongs based on the voltage recovery amplitude;

[0112] S224: Start the stabilization timer based on the sensitivity corresponding to the threshold range.

[0113] Specifically, in step S221, presetting multiple voltage recovery amplitude threshold ranges means dividing the voltage recovery amplitude range into several discrete intervals based on the characteristics of grid voltage recovery and actual application requirements. For example, intervals such as "small amplitude recovery," "medium amplitude recovery," and "large amplitude recovery" can be set. Simultaneously, a corresponding stabilization timer activation sensitivity is configured for each preset threshold interval. This means that the response speed or conditions for stabilization timer activation will differ for different voltage recovery amplitudes. For example, a higher sensitivity may be needed for small amplitude recovery to ensure timely response; a lower sensitivity may be needed for large amplitude recovery to avoid false triggering. These sensitivity values ​​can be pre-set and stored based on the experience of those skilled in the art.

[0114] In step S222, the voltage recovery amplitude can be expressed as the difference between the voltage before and after recovery.

[0115] In practical applications, in step S223, determining the threshold range to which the voltage recovery amplitude belongs based on the voltage recovery amplitude means comparing the real-time detected voltage recovery amplitude with multiple preset voltage recovery amplitude threshold ranges to determine which specific range the current voltage recovery amplitude falls into.

[0116] For example, in some preferred embodiments, it is assumed that three voltage recovery amplitude threshold ranges are preset: Range 1: Voltage recovery amplitude is less than 5% of the rated voltage, corresponding to high sensitivity (e.g., a stabilization timer is started 0.1 seconds after the voltage recovers to above the threshold). Range 2: Voltage recovery amplitude is between 5% and 15% of the rated voltage, corresponding to medium sensitivity (e.g., a stabilization timer is started 0.5 seconds after the voltage recovers to above the threshold). Range 3: Voltage recovery amplitude is greater than 15% of the rated voltage, corresponding to low sensitivity (e.g., a stabilization timer is started 1 second after the voltage recovers to above the threshold).

[0117] When a load change occurs in the power grid, and the voltage recovers from below a preset threshold:

[0118] If the detected voltage recovery amplitude is 3% of the rated voltage (belonging to range 1), the system will select high sensitivity, and the stabilization timer will start immediately after the voltage recovers to 0.1 seconds above the threshold value.

[0119] If the detected voltage recovery amplitude is 10% of the rated voltage (belonging to interval 2), the system will select medium sensitivity, and the stabilization timer will start 0.5 seconds after the voltage recovers to above the threshold value.

[0120] If the detected voltage recovery amplitude is 20% of the rated voltage (belonging to range 3), the system will select low sensitivity, and the stabilization timer will start 1 second after the voltage recovers to above the threshold value.

[0121] Through the above technical solution, this application can adaptively adjust the starting sensitivity of the stabilization timer according to the different voltage recovery amplitudes. Compared with the solution using fixed sensitivity, this application significantly improves the accuracy and adaptability of the stabilization timer starting, especially when the voltage recovery amplitude varies due to load switching. It can more accurately capture the voltage stabilization state, thereby effectively avoiding misjudgments or omissions caused by improper timer starting, and thus improving the overall reliability and accuracy of fault detection in the circuit breaker protection detection module.

[0122] Furthermore, step S23 includes:

[0123] S231: Pause the main undervoltage timer and generate a timer start signal, which is used to trigger the interrupt service routine;

[0124] S232: In the interrupt service routine, start the stable timer according to the selected stable timer start strategy;

[0125] S233: The stabilization timer uses periodic timer interrupts to accumulate the stabilization time of the voltage.

[0126] Specifically, when the voltage recovers to above a preset threshold, the main undervoltage timer is paused. Simultaneously, to ensure the stabilization timer can be started promptly and accurately, the system generates a timing start signal. This timing start signal can be understood as an event-triggered mechanism, its purpose being to decouple the stabilization timer's start operation from the main program flow and respond via an interrupt mechanism.

[0127] The timing start signal is designed to trigger a predefined interrupt service routine. An interrupt service routine is a special type of program segment in the prior art. It works by being executed immediately by the processor when a specific hardware or software event (such as the generation of the timing start signal) occurs, without waiting for the currently executing task to complete.

[0128] In practical applications, interrupt service routines can be configured with high priority to ensure a rapid response to the timing start signal. Within the interrupt service routine, the stabilizing timer is started according to the previously selected stabilizing timer start strategy. This means that the start of the stabilizing timer is no longer limited by the execution progress of the main program, but is guaranteed by the real-time nature of the interrupt. Once the stabilizing timer is started, its time accumulation is not achieved through a simple software loop, but rather by utilizing periodic timer interrupts. Periodic timer interrupts are interrupts automatically generated by a hardware timer within a preset time interval; each time an interrupt occurs, the stabilizing timer's time value is updated or incremented.

[0129] It is precisely because of this interrupt-based real-time response and hardware-assisted precise timing that the accumulation of stable voltage time is more accurate and reliable, effectively solving the problem of insufficient timing accuracy that may exist in traditional solutions.

[0130] Furthermore, step S3 includes:

[0131] S31: Obtain the depth information of the voltage drop, which includes the maximum deviation of the voltage from a preset threshold value during the voltage drop.

[0132] S32: Obtain the frequency information of voltage crossing the threshold within a preset analysis time window. The frequency information includes the number of times the voltage recovers from below the preset threshold value to above the preset threshold value within the preset analysis time window.

[0133] S33: Determine the preset settling time based on the maximum deviation value and the number of times the threshold is crossed;

[0134] S34: If the accumulated stabilization time reaches the preset stabilization time, the undervoltage time will be cleared to zero.

[0135] S35: If the voltage stabilization time does not reach the preset stabilization time and the voltage falls below the preset threshold again, the main undervoltage timer will be started to continue accumulating the undervoltage time.

[0136] Specifically, when the grid voltage drops from its normal value and falls below a preset threshold, the system continuously monitors the lowest voltage point and uses the difference between this lowest point and the preset threshold as the maximum deviation value. This maximum deviation value reflects the severity of the voltage drop and aims to quantify its instantaneous impact.

[0137] Within a preset analysis time window (i.e., a period pre-defined by technicians), the system records the number of times the voltage recovers from an undervoltage state to a normal state. This frequency information is intended to reflect the activity and stability of voltage fluctuations, with the aim of assessing the transient disturbance characteristics of the power grid.

[0138] Based on the maximum deviation value and the number of times the threshold is crossed, the preset settling time is determined. This means that the settling time is no longer a fixed value, but is dynamically adjusted according to the actual voltage fluctuation characteristics. The purpose is to make the setting of the settling time more flexible and precise to adapt to voltage disturbances of different degrees and frequencies.

[0139] If the accumulated voltage stabilization time reaches the dynamically determined preset stabilization time, the undervoltage time is reset to zero, indicating that the voltage has stabilized and there is no need to continue accumulating the undervoltage time. Conversely, if the voltage stabilization time does not reach the preset stabilization time and the voltage drops below the preset threshold again, the main undervoltage timer is restarted to continue accumulating the undervoltage time, ensuring that the accumulation of the undervoltage state is continuous and accurate before the voltage is truly stabilized.

[0140] In traditional solutions, the preset settling time is usually a fixed value, which may not provide optimal timing logic when facing complex and variable grid voltage fluctuations. For example, a fixed settling time may lead to misjudgments or missed judgments for voltage dips that are deep but short-lived, or voltage disturbances that are shallow but fluctuate frequently. By obtaining the maximum deviation value of the voltage dip, the system can quantify the severity of the voltage dip. When the voltage dip is deep, a longer settling time may be needed to confirm the true recovery of the voltage, in order to avoid misjudging stability due to a brief rebound. At the same time, by obtaining the number of times the voltage crosses the threshold, the system can identify the frequency of voltage fluctuations. If the voltage fluctuates frequently around the preset threshold value in a short period of time, this may indicate the presence of persistent instability in the grid. In this case, a longer settling time is needed to ensure complete voltage stabilization, thereby avoiding prematurely resetting the undervoltage time due to instantaneous recovery.

[0141] Therefore, the solution proposed in this application can intelligently adjust the settling time according to the actual characteristics (depth and frequency) of the voltage drop, making the timing logic more closely match the actual power grid operation. This dynamic adjustment mechanism ensures that when voltage fluctuations are severe, the system has sufficient time to confirm the true stability of the voltage, while when voltage fluctuations are minor, it can respond more quickly, thereby improving the accuracy and robustness of fault detection.

[0142] In some of the embodiments described above in this application, a preset settling time is determined based on the voltage drop depth information and the voltage crossing threshold frequency information. However, in practical applications, the voltage fluctuation of the power grid is complex and variable. If the preset settling time cannot be dynamically adjusted according to the specific voltage drop characteristics, it may lead to misjudgment of the timing logic or untimely clearing, affecting the accuracy and reliability of fault detection.

[0143] In this regard, this application further proposes that step S32 includes:

[0144] S321: When the maximum deviation value is less than the first preset deviation threshold and the number of times the threshold is crossed is greater than the first preset frequency threshold, the preset stabilization time is set to the first stabilization time value.

[0145] S322: When the maximum deviation value is greater than the second preset deviation threshold and the number of times the threshold is crossed is less than the second preset frequency threshold, the preset stabilization time is set to the second stabilization time value.

[0146] The first steady-state time value is less than the second steady-state time value.

[0147] The first preset deviation threshold and the second preset deviation threshold are critical values ​​used to distinguish different voltage drop depths. For example, the first preset deviation threshold can be set to a smaller voltage deviation, indicating a shallow drop; the second preset deviation threshold can be set to a larger voltage deviation, indicating a deep drop. The first preset frequency threshold and the second preset frequency threshold are critical values ​​used to distinguish different voltage fluctuation frequencies. For example, the first preset frequency threshold can be set to a higher number of crossings, indicating frequent fluctuations; the second preset frequency threshold can be set to a lower number of crossings, indicating infrequent fluctuations.

[0148] In practical applications, when the voltage drop is shallow (maximum deviation less than the first preset deviation threshold) and fluctuations are frequent (number of threshold crossings greater than the first preset frequency threshold), the system may be in an unstable state with continuous small fluctuations. In this case, a short settling time is needed for a rapid response; therefore, the preset settling time is set as the first settling time value. Conversely, when the voltage drop is deep (maximum deviation greater than the second preset deviation threshold) and fluctuations are infrequent (number of threshold crossings less than the second preset frequency threshold), the system may have experienced severe transient disturbances. A longer settling time is needed to ensure that the voltage truly recovers and to avoid misjudgment; therefore, the preset settling time is set as the second settling time value. By setting the first settling time value to be less than the second settling time value, adaptive adjustment to different voltage disturbance characteristics can be achieved.

[0149] The solution proposed in this application introduces information on the depth of voltage drop (maximum deviation value) and the frequency of voltage crossing the threshold (number of times the threshold is crossed), and dynamically adjusts the preset settling time based on different combinations of these information, thereby solving the problem that the settling time setting may not be flexible enough in traditional solutions.

[0150] In some preferred embodiments, a specific example is given below. Assume a preset threshold value of 200V. A first preset deviation threshold can be set to 10V, and a second preset deviation threshold to 50V. Simultaneously, a first preset frequency threshold is set to 5 times / second, and a second preset frequency threshold is set to 1 time / second. A first settling time value can be set to 0.5 seconds, and a second settling time value can be set to 2 seconds. Specifically:

[0151] Scenario 1: When a voltage drop is continuously detected, with a maximum deviation of 8V (less than the first preset deviation threshold of 10V), and the voltage crosses the threshold 6 times / second within the analysis time window (greater than the first preset frequency threshold of 5 times / second), the system determines this as a slight and frequent voltage fluctuation and sets the preset stabilization time to the first stabilization time value of 0.5 seconds. This means that as long as the voltage recovers and stabilizes for 0.5 seconds, the main undervoltage timer can be reset to zero, thus quickly responding and resuming normal timing.

[0152] Scenario 2: When a voltage drop is continuously detected, with a maximum deviation of 60V (greater than the second preset deviation threshold of 50V), and the number of times the voltage crosses the threshold within the analysis time window is 0.5 times / second (less than the second preset frequency threshold of 1 time / second), the system determines this as a severe but infrequent voltage drop and sets the preset stabilization time to the second stabilization time value of 2 seconds. This means that the main undervoltage timer will only be reset to zero after the voltage recovers and stabilizes for 2 seconds, ensuring that the system has sufficient time to recover and stabilize after experiencing severe disturbances, thus avoiding misjudgment.

[0153] In this way, the circuit breaker protection detection module can intelligently adjust its timing logic according to the actual grid voltage characteristics, thereby improving the robustness of fault detection.

[0154] Furthermore, step S4 includes:

[0155] S44: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, during the continuous monitoring period, record the duration of each consecutive drop event in which the voltage drops from above the preset threshold to below the preset threshold and remains below the preset threshold until it recovers to above the preset threshold again.

[0156] S45: Determine whether any of the recorded single consecutive drop events has a drop duration exceeding the preset undervoltage state confirmation delay setting value.

[0157] S46: If present, send a standard undervoltage fault report;

[0158] S47: If not present, send a timing logic error report.

[0159] This application's solution, by no longer merely determining whether a single voltage drop meets the conditions when the accumulated undervoltage time reaches a preset threshold, but instead meticulously recording and analyzing the duration of each individual consecutive voltage drop event, solves the problem of misclassification of fault types that may exist in the aforementioned basic technical solutions under complex voltage fluctuation scenarios. Specifically, when the accumulated undervoltage time reaches a preset undervoltage state confirmation delay setting, the system iterates through all voltage drop events that occurred during the continuous monitoring period. By accurately recording the start and end times of each individual consecutive voltage drop event and calculating its duration, the system can obtain a comprehensive list of voltage drop events. Subsequently, by determining whether any individual consecutive voltage drop event in this list has a duration exceeding the preset undervoltage state confirmation delay setting, this application can more accurately identify true, continuous undervoltage faults. This meticulous event recording and judgment mechanism enables the system to distinguish between faults caused by a single long undervoltage event and timing anomalies caused by the accumulation of multiple short transient fluctuations, thereby avoiding misclassification of non-fault fluctuations as conventional undervoltage faults.

[0160] Please refer to Figure 2 , Figure 3 A circuit breaker protection detection module fault detection system, used to implement any of the above methods, the system comprising:

[0161] First timing module 201: continuously monitors the voltage of the power grid. When the voltage is lower than the preset threshold, it starts the main undervoltage timer to accumulate the undervoltage time when the voltage drops.

[0162] Second timing module 202: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery;

[0163] Third timing module 203: If the accumulated stable voltage time reaches the preset stable time, the undervoltage time will be cleared to zero; if the stable voltage time does not reach the preset stable time and the voltage is lower than the preset threshold again, the main undervoltage timer will be started to continue accumulating the undervoltage time.

[0164] Fault detection module 204: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, it determines whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, a regular undervoltage fault report is sent; otherwise, a timing logic error report is sent.

[0165] Specifically, the first timing module 201 is configured to continuously monitor the voltage of the power grid. When the voltage is detected to be lower than a preset threshold, the first timing module 201 is triggered to start a main undervoltage timer. This main undervoltage timer is used to accurately accumulate the undervoltage time during the voltage drop, ensuring accurate recording of the duration of the undervoltage event. The preset threshold can be set according to the actual application scenario and power grid standards; for example, it can be set as a certain percentage of the rated voltage.

[0166] The second timing module 202 is configured to intervene when the voltage recovers to above the preset threshold value. At this time, the second timing module 202 pauses the main undervoltage timer to stop the accumulation of undervoltage time. Simultaneously, the second timing module 202 starts a stabilization timer to accumulate the stable voltage time after voltage recovery. This is intended to evaluate the stability and sustainability of voltage recovery, providing a basis for subsequent logical judgments.

[0167] The third timing module 203 is responsible for logically processing the undervoltage time based on the accumulated stabilization timer. Specifically, if the accumulated stabilization time reaches a preset stabilization time, it indicates that the voltage has stabilized and recovered. At this time, the third timing module 203 will reset the previously accumulated undervoltage time to zero, preparing for the next possible undervoltage event. However, if the accumulated stabilization time does not reach the preset stabilization time, and the voltage drops below the preset threshold value again, the third timing module 203 will restart the main undervoltage timer and continue to accumulate the undervoltage time to cope with repeated voltage fluctuations. The preset stabilization time can be flexibly configured according to the system's voltage stability requirements.

[0168] The fault detection module 204 is configured to perform a final fault judgment when the accumulated undervoltage time reaches a preset undervoltage state confirmation delay setting. This module determines whether, within the continuous monitoring period, there is a single voltage drop whose duration exceeds the preset undervoltage state confirmation delay setting. If such a single continuous drop event exists, the fault detection module sends a standard undervoltage fault report, indicating that an expected undervoltage fault has occurred. If not, meaning that the duration of all single drop events does not exceed the setting, but the accumulated undervoltage time has, it indicates a possible anomaly in the timing logic. In this case, the fault detection module 204 sends a timing logic error report, indicating a potential problem with the system's internal timing or logic processing. The preset undervoltage state confirmation delay setting is a key parameter used to distinguish between instantaneous voltage drops and persistent undervoltage faults.

[0169] This application's solution maps key logical steps in the circuit breaker protection detection module's fault detection method to independent hardware or software modules, thereby transforming the abstract method flow into an operable and deployable system entity. The first timing module 201 continuously monitors the voltage and starts the main undervoltage timer, ensuring accurate capture and time accumulation of voltage drop events. The second timing module 202 takes over the timing task when the voltage recovers, pausing the main undervoltage timer and starting a stabilization timer, achieving a smooth switching of timing states. The third timing module 203 intelligently decides whether to reset the undervoltage time or continue accumulating it based on the stabilization voltage time, effectively handling the complex scenarios of voltage fluctuations and recovery. Finally, the fault detection module 204 performs the final fault judgment and report based on the accumulated undervoltage time, distinguishing between regular undervoltage faults and timing logic errors, improving the accuracy of fault diagnosis. It is precisely this modular design that allows the entire fault detection method to operate efficiently and stably in actual systems, avoiding implementation difficulties and potential errors caused by the method's abstraction.

[0170] Through the above technical solution, this application provides a concrete circuit breaker protection detection module fault detection system, effectively solving the abstraction problems that may exist in the actual deployment and operation of pure method solutions. The system, through clear module division, clarifies the responsibilities of each functional unit, improving the system's feasibility, maintainability, and reliability. The modular design facilitates system integration and expansion, reduces the complexity of development and debugging, and ensures the stable and efficient execution of the circuit breaker protection detection module fault detection method, thereby enhancing the safety and stability of power grid operation.

[0171] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0172] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A fault detection method for a circuit breaker protection detection module, characterized in that, The method includes the following steps: S1: Continuously monitor the voltage of the power grid. When the voltage is lower than the preset threshold, start the main undervoltage timer to accumulate the undervoltage time when the voltage drops. S2: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery; Step S2 includes: S21: When the voltage recovers to a value exceeding the preset threshold, obtain the current operating mode of the circuit breaker protection detection module; S22: Select the corresponding stable timer startup strategy according to the current operating mode; the stable timer startup strategy includes: In system startup mode, the stabilization timer starts after a preset time delay following voltage recovery; In load switching mode, the stabilization timer is activated based on the sensitivity corresponding to the voltage recovery amplitude; S23: Pause the main undervoltage timer and start the stabilization timer according to the selected stabilization timer start strategy to accumulate the stabilization voltage time; S3: If the accumulated stable voltage time reaches the preset stable time, the undervoltage time is reset to zero; if the stable voltage time does not reach the preset stable time and the voltage is lower than the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time. S4: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, determine whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, send a regular undervoltage fault report; otherwise, send a timing logic error report.

2. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, In step S4, the step of sending a timing logic error report if it does not exist includes the following steps: S41: If not, determine whether there are multiple instances during the continuous monitoring period where the voltage recovers from below the preset threshold to above the preset threshold and the stabilization time does not reach the preset stabilization time. S42: If not present, send a timing sampling or reset error report; S43: If present, send a timing logic error report.

3. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, Step S1 includes: S11: Continuously monitor the voltage of the power grid. When the voltage is lower than the preset threshold value for the first time, start the confirmation timer to accumulate the confirmation undervoltage time. S12: When the confirmation undervoltage time reaches the preset confirmation duration and the voltage remains below the preset threshold, the main undervoltage timer is started to accumulate the undervoltage time; S13: If the confirmation undervoltage time does not reach the preset confirmation duration and the voltage recovers to a value exceeding the preset threshold, then the confirmation timer is reset.

4. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, In step S22, the step of starting the stabilization timer according to the sensitivity corresponding to the voltage recovery amplitude in the load switching mode includes the following steps: S221: Preset multiple voltage recovery amplitude threshold ranges and configure the corresponding stable timer start sensitivity for each threshold range; S222: Real-time detection of the voltage recovery amplitude; S223: Determine the threshold range to which the voltage recovery amplitude belongs based on the voltage recovery amplitude; S224: Start the stabilization timer according to the sensitivity corresponding to the threshold range.

5. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, Step S23 includes: S231: Pause the main undervoltage timer and generate a timing start signal, which is used to trigger the interrupt service routine; S232: In the interrupt service routine, the stable timer is started according to the selected stable timer start strategy; S233: The stabilization timer uses periodic timing interrupts to accumulate the stabilization voltage time.

6. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, Step S3 includes: S31: Obtain the depth information of the voltage drop, the depth information including the maximum deviation value of the voltage from the preset threshold value during the voltage drop; S32: Obtain frequency information of voltage crossing threshold within a preset analysis time window, wherein the frequency information includes the number of times the voltage recovers from below the preset threshold value to above the preset threshold value within the preset analysis time window; S33: Determine the preset stabilization time based on the maximum deviation value and the number of times the threshold is crossed; S34: If the accumulated stable voltage time reaches the preset stable time, then the undervoltage time is cleared to zero; S35: If the voltage stabilization time does not reach the preset stabilization time and the voltage falls below the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time.

7. A fault detection method for a circuit breaker protection detection module according to claim 6, characterized in that, Step S32 includes: S321: When the maximum deviation value is less than the first preset deviation threshold and the number of times the threshold is crossed is greater than the first preset frequency threshold, the preset stabilization time is set to the first stabilization time value. S322: When the maximum deviation value is greater than the second preset deviation threshold and the number of times the threshold is crossed is less than the second preset frequency threshold, the preset stabilization time is set to the second stabilization time value. The first settling time value is less than the second settling time value.

8. The fault detection method for a circuit breaker protection detection module according to claim 1, characterized in that, Step S4 includes: S44: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, during the continuous monitoring period, record the duration of each consecutive drop event in which the voltage drops from above the preset threshold value to below the preset threshold value and remains below the preset threshold value until it recovers to above the preset threshold value again. S45: Determine whether any of the recorded single consecutive drop events has a drop duration exceeding the preset undervoltage state confirmation delay setting value. S46: If present, send a standard undervoltage fault report; S47: If not present, send a timing logic error report.

9. A fault detection system for a circuit breaker protection detection module, characterized in that, The system for implementing the method according to any one of claims 1-8 comprises: First timing module: continuously monitors the voltage of the power grid. When the voltage is lower than a preset threshold, the main undervoltage timer is started to accumulate the undervoltage time during the voltage drop. Second timing module: When the voltage recovers to a value exceeding the preset threshold, pause the main undervoltage timer and start the stabilization timer to accumulate the stabilization time during voltage recovery; The second timing module is also used to obtain the current operating mode of the circuit breaker protection detection module when the voltage recovers to a value exceeding the preset threshold. Based on the current operating mode, a corresponding stable timer startup strategy is selected; the stable timer startup strategy includes: In system startup mode, the stabilization timer starts after a preset time delay following voltage recovery; In load switching mode, the stabilization timer is activated based on the sensitivity corresponding to the voltage recovery amplitude; Pause the main undervoltage timer and start the stabilization timer according to the selected stabilization timer start strategy to accumulate the stabilization voltage time; Third timing module: If the accumulated stable voltage time reaches the preset stable time, the undervoltage time is cleared to zero; if the stable voltage time does not reach the preset stable time and the voltage is lower than the preset threshold value again, the main undervoltage timer is started to continue accumulating the undervoltage time. Fault detection module: When the accumulated undervoltage time reaches the preset undervoltage state confirmation delay setting value, it determines whether there is a voltage drop during the continuous monitoring period where the duration of the drop exceeds the preset undervoltage state confirmation delay setting value. If so, a regular undervoltage fault report is sent; otherwise, a timing logic error report is sent.

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