Contactor state monitoring method, device, equipment, medium and product

Abstract

The invention relates to the technical field of contactor state monitoring, in particular to a contactor state monitoring method, device, equipment, medium and product, and the method comprises the steps: building a three-phase current after a vacuum isolation contactor is closed, transmitting a breaking instruction for breaking the vacuum isolation contactor after a preset time is delayed, and recording the breaking moment; obtaining the duration of the three-phase current value from the breaking moment to a preset current threshold; judging whether a vacuum tube of the vacuum isolation contactor leaks or not based on the duration that the three-phase current value is reduced to a preset current threshold value from the breaking moment; existing equipment can be used for monitoring whether the contactor has vacuum leakage or not on line.

Description

Technical Field

[0001] This invention relates to the field of contactor condition monitoring technology, and particularly to a contactor condition monitoring method, apparatus, equipment, medium, and product. Background Technology

[0002] Highly efficient and energy-saving permanent magnet traction systems are widely used in rail transit. To ensure system safety, a vacuum isolation contactor is installed between the traction inverter and the permanent magnet traction motor to achieve electrical isolation in case of fault. The vacuum contactor relies on the vacuum environment of its vacuum tube for arc extinguishing. Once the vacuum tube leaks and the vacuum level drops, its arc extinguishing performance will deteriorate sharply, potentially leading to contact erosion, system failure, or even safety accidents. A technical problem in this field exists regarding how to monitor the contactor's status. Summary of the Invention

[0003] This invention provides a contactor status monitoring method, apparatus, equipment, medium, and product, solving the technical problem of how to monitor the status of contactors.

[0004] In a first aspect, the present invention provides a contactor status monitoring method, comprising: step S02, establishing a three-phase current after the vacuum isolating contactor is closed, issuing a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and recording the disconnection time; step S03, obtaining the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; and step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold.

[0005] In some embodiments, the method further includes: step S01, generating a diagnostic start flag based on meeting safety conditions, the diagnostic start flag being used to start contactor status monitoring; wherein the safety conditions include: the train being powered on for the first time, the high-speed circuit breaker being in a closed state, the vehicle being in a stationary state, and the intermediate support capacitor voltage being greater than a preset value.

[0006] In some embodiments, the method further includes: step S05, if a vacuum tube leak is confirmed, a fault code is generated and reported to the cab display and the ground maintenance center, and the diagnostic data is stored at the same time.

[0007] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: step S041, taking the maximum value among the U-phase drop time, V-phase drop time, and W-phase drop time as the shut-off time; step S042, if the shut-off time is greater than a preset fault threshold, then a leak is initially determined.

[0008] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, further includes step S043, if the duration of two or more of the U-phase drop time, V-phase drop time, and W-phase drop time is greater than a preset fault threshold, then a leak is confirmed.

[0009] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: sorting the U-phase fall time, V-phase fall time, and W-phase fall time by numerical value to obtain the maximum and minimum fall time values; calculating the absolute deviation and relative deviation based on the maximum and minimum fall time values, wherein the absolute deviation is the maximum fall time minus the minimum fall time value, and the relative deviation is the ratio of the absolute deviation to the minimum fall time value; and determining whether the vacuum tube is leaking based on the numerical range of the relative deviation.

[0010] Secondly, the present invention provides a contactor status monitoring device, comprising: a testing module, configured to establish a three-phase current after the vacuum isolating contactor is closed, issue a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and record the disconnection time; a data acquisition module, configured to acquire the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; and a leakage judgment module, configured to determine whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold.

[0011] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method of any of the above aspects.

[0012] Fourthly, the present invention provides an electronic device including a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the method of any of the above aspects.

[0013] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements a method for any of the above aspects.

[0014] This invention provides a contactor status monitoring method, device, equipment, medium, and product. The method includes: step S02, establishing a three-phase current after the vacuum isolating contactor is closed, issuing a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and recording the disconnection time; step S03, obtaining the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; and step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold. This allows for online monitoring of whether a vacuum leak has occurred in the contactor using existing equipment. Attached Figure Description

[0015] The invention will now be described in more detail with reference to embodiments and the accompanying drawings: Figure 1 This is a schematic flowchart of a contactor status monitoring method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a contactor status monitoring device provided in an embodiment of the present invention.

[0016] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention and to fully understand and implement the process of how the present invention uses technical means to solve technical problems and achieve corresponding technical effects, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The embodiments of the present invention and the various features therein can be combined with each other without conflict, and the resulting technical solutions are all within the protection scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0019] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0020] Highly efficient and energy-saving permanent magnet traction systems are widely used in rail transit. To ensure system safety, a vacuum isolation contactor is installed between the traction inverter and the permanent magnet traction motor to achieve electrical isolation in case of fault. The vacuum contactor relies on the vacuum environment of its vacuum tube for arc extinguishing. Once the vacuum tube leaks and the vacuum level drops, its arc extinguishing performance will deteriorate sharply, potentially leading to contact erosion, system failure, or even safety accidents. A technical problem in this field exists regarding how to monitor the contactor's status.

[0021] To address the aforementioned technical problem of how to monitor the status of contactors, this invention proposes a contactor status monitoring method, apparatus, equipment, medium, and product. The implementation details of this invention are described below. The following content is only for ease of understanding and is not essential for implementing this solution.

[0022] Example 1 Figure 1 This is a flowchart illustrating a contactor status monitoring method provided in an embodiment of this application, as shown below. Figure 1 As shown, in the technical solution of this embodiment, a contactor status monitoring method is provided, including: step S02, establishing a three-phase current after the vacuum isolating contactor is closed, issuing a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and recording the disconnection time; step S03, obtaining the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold.

[0023] The technical problem this embodiment aims to solve is how to determine whether the vacuum tube of a vacuum isolating contactor is leaking. In the permanent magnet traction system of high-speed trains, vacuum tube leakage can lead to a decrease in arc extinguishing capability and cause safety hazards. Related offline detection requires specialized instruments and has poor real-time performance; some online solutions require additional sensors, increasing cost and complexity. Therefore, there is a technical problem in the art of how to utilize existing equipment and signals to achieve vacuum tube leakage detection without additional hardware.

[0024] In this embodiment, the traction control unit (TCU) executes a specific sequence of operations: First, it controls the vacuum isolating contactor to close. After confirming the vacuum isolating contactor is closed, a delay of T1 (e.g., 100ms) is made, and a pulse command with a duration of T2 (e.g., 1s) and a preset frequency (e.g., 50Hz) is sent to the inverter to establish a stable three-phase current. After a delay of T3 (e.g., 200ms) to ensure the current is stable, a disconnection command is issued and the time T_break is recorded. Subsequently, the time it takes for the three-phase current to drop from T_break to a preset threshold (e.g., 10A) is obtained, and leakage is determined based on this time. This process utilizes existing TCUs, current sensors, and other equipment, without requiring additional hardware.

[0025] The technical solution in this embodiment achieves online leakage detection by utilizing existing system equipment and signals. It eliminates the need for dedicated instruments or additional sensors, reducing costs and complexity; real-time current signals improve the real-time performance of the detection, avoiding the lag of offline detection; standardized operation sequences ensure consistent results, effectively identifying problems of decreased arc-extinguishing capability and improving train operation safety.

[0026] Example 2 Based on the above embodiments, the method further includes: step S01, generating a diagnostic start flag based on meeting safety conditions, the diagnostic start flag being used to start contactor status monitoring; wherein, the safety conditions include: the train being powered on for the first time, the high-speed circuit breaker being in a closed state, the vehicle being in a stationary state, and the intermediate support capacitor voltage being greater than a preset value.

[0027] The technical problem this embodiment aims to solve is how to ensure the safe detection of vacuum tube leaks in vacuum isolators. Therefore, there is a technical problem in the art of setting safe triggering conditions to ensure a safe and reliable diagnostic process.

[0028] In the technical solution of this embodiment, the diagnostic flag is automatically generated at a preset cycle, which must simultaneously meet the following safety conditions: the train is powered on for the first time, the high-speed circuit breaker is closed, the vehicle is stationary, and the voltage of the intermediate support capacitor is greater than a preset value (e.g., 1000V). These conditions ensure that the diagnosis is performed in the initial stage of power-on while the vehicle is stationary; the capacitor voltage is sufficient to ensure current stability and avoid data errors.

[0029] The technical solution in this embodiment achieves seamless and safe diagnostics through safe triggering conditions. Triggering during static power-on does not affect normal operation; capacitor voltage requirements ensure stable current, improving the accuracy of results; periodic automatic triggering eliminates the need for manual intervention, enabling continuous status monitoring and significantly improving train operation safety.

[0030] Example 3 Based on the above embodiments, the method further includes: step S05, if a vacuum tube leak is confirmed, a fault code is generated and reported to the cab display and the ground maintenance center, and the diagnostic data is stored at the same time.

[0031] The technical problem this embodiment aims to solve is how to report vacuum tube leaks after detection. If existing solutions fail to promptly alert or store data after detecting a leak, the fault may go unaddressed, potentially leading to an accident; furthermore, the lack of historical data hinders subsequent trend analysis. Therefore, there is a technical problem in this field of how to promptly report faults and save data.

[0032] In the technical solution of this embodiment, after confirming that the vacuum tube is leaking: the TCU generates a high-level fault code; it reports to the cab display and ground maintenance center through the vehicle network, clearly indicating "XX axis isolating contactor vacuum tube is leaking, please check and replace immediately"; at the same time, it stores the diagnostic data (such as turn-off time, three-phase fall time, current waveform) to the data unit for subsequent analysis.

[0033] The technical solution in this embodiment improves fault handling efficiency and maintenance planning through timely reporting and data storage. Real-time fault reporting allows maintenance personnel to respond quickly and avoid accidents; clear prompts indicate the specific axis location, reducing troubleshooting time; data storage provides a foundation for threshold self-learning and trend prediction, assisting in predictive maintenance and upgrading from reactive alarms to proactive warnings, reducing the risk of operational interruptions.

[0034] Example 4 Based on the above embodiment, step S04, determining whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: step S041, taking the maximum value among the U-phase drop time, V-phase drop time, and W-phase drop time as the shutdown time; step S042, if the shutdown time is greater than the preset fault threshold, then a preliminary judgment of leakage is made.

[0035] The technical problem this embodiment aims to solve is how to preliminarily determine whether the vacuum tube of a vacuum isolating contactor is leaking based on a preset fault threshold. A leak in the vacuum tube prolongs the arc-extinguishing time, requiring quantifiable indicators to initially identify the leak. Therefore, there is a technical problem in the art of how to use the turn-off time to compare with a preset threshold to achieve a preliminary leak detection.

[0036] In this embodiment, the maximum value of the three-phase current drop time (U, V, W) is used as the turn-off duration (T_off), reflecting the duration of the final extinguished arc. Then, T_off is compared with a preset fault threshold (e.g., 20ms). If T_off is greater than the threshold, a preliminary leak is determined. This process utilizes existing current sensor signals and requires no additional hardware.

[0037] The technical solution in this embodiment achieves accurate preliminary judgment by comparing the quantified shutdown duration with a threshold. The maximum value of the three phases is used to cover the most severe arc-extinguishing situation, avoiding missed detections; the preset threshold is set based on the normal arc-extinguishing time, ensuring the standard's rationality; no additional hardware is required, reducing costs and improving leakage identification efficiency.

[0038] Example 5 Based on the above embodiment, step S04, which determines whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, further includes: step S043, which confirms leakage if the duration of two or more of the U-phase drop time, V-phase drop time, and W-phase drop time is greater than a preset fault threshold.

[0039] The technical problem this embodiment aims to solve is how to further determine whether the vacuum tube of a vacuum isolating contactor is leaking based on a preset fault threshold. A preliminary judgment based solely on a shutdown duration exceeding the threshold is prone to misjudgment due to single-phase sensor malfunctions or interference. Therefore, there is a technical problem in the art of improving the reliability of the judgment through multi-phase verification.

[0040] In this embodiment, cross-verification is performed based on the initial judgment: if two or more of the three phases (U, V, and W) have a timeout exceeding a preset fault threshold, then a vacuum tube leak is confirmed. The consistency of the three-phase current is utilized to eliminate the influence of momentary faults or interference from single-phase sensors. For example, a timeout in only one phase may indicate a sensor problem, while timeouts in two or more phases are more likely to indicate a vacuum tube leak.

[0041] The technical solution in this embodiment greatly improves the reliability of judgment through three-phase cross-validation. It eliminates misjudgments caused by interference from single-phase sensors and reduces unnecessary maintenance; multi-phase data judgment is more systematic and avoids the limitations of single-point judgment; combined with the preliminary judgment, it forms a double verification to ensure the accuracy of the result.

[0042] Example 6 Based on the above embodiments, step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: sorting the U-phase drop time, V-phase drop time, and W-phase drop time by numerical value to obtain the maximum and minimum drop time values; calculating the absolute deviation and relative deviation based on the maximum and minimum drop time values, where the absolute deviation is the maximum drop time minus the minimum drop time value, and the relative deviation is the ratio of the absolute deviation to the minimum drop time value; and determining whether the vacuum tube is leaking based on the numerical range of the relative deviation.

[0043] The technical problem this embodiment aims to solve is how to determine whether the vacuum tube of a vacuum isolating contactor is leaking based solely on the three-phase current drop time. Related solutions rely on preset thresholds from historical data, which cannot adapt to individual differences or insufficient data. Therefore, there is a technical problem in the art of how to determine leakage without relying on historical data.

[0044] In this embodiment, the three-phase fall times are sorted to obtain the maximum value (T_max) and the minimum value (T_min); the absolute deviation (D_abs=T_max-T_min) and the relative deviation (D_rel=D_abs / T_min×100%) are calculated; the warning level is determined according to the range of D_rel: for example, 15%-30% is a level 1 warning (potential degradation), 30%-50% is a level 2 warning (significant degradation), and ≥50% is a level 3 warning (proximate fault). At the same time, the abnormal phase corresponding to T_max is located.

[0045] The technical solution in this embodiment achieves judgments independent of historical data through relative deviation analysis. Relative deviation eliminates the influence of individual differences; for example, different contactors may have different normal shut-off times, but relative deviation can reflect anomalies. Graded early warning systems detect potential degradation in advance, preventing fault escalation. Abnormal phase location reduces troubleshooting time and improves maintenance efficiency.

[0046] Example 7 Figure 2 This is a schematic diagram of the structure of a contactor status monitoring device provided in an embodiment of this application, as shown below. Figure 2 As shown, in this embodiment, a contactor status monitoring device is provided, including: a testing module, used to establish a three-phase current after the vacuum isolating contactor is closed, issue a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and record the disconnection time; a data acquisition module, used to acquire the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; and a leakage judgment module, used to determine whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold.

[0047] The technical problem this embodiment aims to solve is how to determine whether the vacuum tube of a vacuum isolating contactor is leaking. In the permanent magnet traction system of high-speed trains, vacuum tube leakage can lead to a decrease in arc extinguishing capability and cause safety hazards. Related offline detection requires specialized instruments and has poor real-time performance; some online solutions require additional sensors, increasing cost and complexity. Therefore, there is a technical problem in the art of how to utilize existing equipment and signals to achieve vacuum tube leakage detection without additional hardware.

[0048] In this embodiment, the traction control unit (TCU) executes a specific sequence of operations: First, it controls the vacuum isolating contactor to close. After confirming the vacuum isolating contactor is closed, a delay of T1 (e.g., 100ms) is made, and a pulse command with a duration of T2 (e.g., 1s) and a preset frequency (e.g., 50Hz) is sent to the inverter to establish a stable three-phase current. After a delay of T3 (e.g., 200ms) to ensure the current is stable, a disconnection command is issued and the time T_break is recorded. Subsequently, the time it takes for the three-phase current to drop from T_break to a preset threshold (e.g., 10A) is obtained, and leakage is determined based on this time. This process utilizes existing TCUs, current sensors, and other equipment, without requiring additional hardware.

[0049] The technical solution in this embodiment achieves online leakage detection by utilizing existing system equipment and signals. It eliminates the need for dedicated instruments or additional sensors, reducing costs and complexity; real-time current signals improve the real-time performance of the detection, avoiding the lag of offline detection; standardized operation sequences ensure consistent results, effectively identifying problems of decreased arc-extinguishing capability and improving train operation safety.

[0050] Other technical features and effects of this embodiment correspond to those of the above embodiments, and will not be repeated here.

[0051] Example 8 In the technical solution of this embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it implements the method of any one of the above embodiments, including: step S02, establishing a three-phase current after the vacuum isolating contactor is closed, issuing a disconnection command for disconnecting the vacuum isolating contactor after a preset delay, and recording the disconnection time; step S03, obtaining the time it takes for the three-phase current value to drop from the disconnection time to a preset current threshold; step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the disconnection time to the preset current threshold.

[0052] In some embodiments, the method further includes: step S01, generating a diagnostic start flag based on meeting safety conditions, the diagnostic start flag being used to start contactor status monitoring; wherein the safety conditions include: the train being powered on for the first time, the high-speed circuit breaker being in a closed state, the vehicle being in a stationary state, and the intermediate support capacitor voltage being greater than a preset value.

[0053] In some embodiments, the method further includes: step S05, if a vacuum tube leak is confirmed, a fault code is generated and reported to the cab display and the ground maintenance center, and the diagnostic data is stored at the same time.

[0054] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: step S041, taking the maximum value among the U-phase drop time, V-phase drop time, and W-phase drop time as the shut-off time; step S042, if the shut-off time is greater than a preset fault threshold, then a leak is initially determined.

[0055] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, further includes step S043, if the duration of two or more of the U-phase drop time, V-phase drop time, and W-phase drop time is greater than a preset fault threshold, then a leak is confirmed.

[0056] In some embodiments, step S04, determining whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, includes: sorting the U-phase fall time, V-phase fall time, and W-phase fall time by numerical value to obtain the maximum and minimum fall time values; calculating the absolute deviation and relative deviation based on the maximum and minimum fall time values, wherein the absolute deviation is the maximum fall time minus the minimum fall time value, and the relative deviation is the ratio of the absolute deviation to the minimum fall time value; and determining whether the vacuum tube is leaking based on the numerical range of the relative deviation.

[0057] Other technical features and effects of this embodiment correspond to those of the above embodiments, and will not be repeated here.

[0058] In the technical solution of this embodiment, an electronic device is provided, including a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the method of any of the above embodiments.

[0059] In the technical solution of this embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the method of any of the above embodiments.

[0060] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for performing the methods in the above embodiments. The computer-readable storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, and may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).

[0061] Computer-readable storage media may also store at least one computer-executable program / instruction, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0062] In addition, the computer device may also include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., a keyboard, mouse, speakers, etc.). The processor can communicate with external devices via the I / O bus through a wired or wireless network. In one embodiment, the at least one computer-executable instruction may also be compiled into or comprise a software product / computer program product, wherein one or more computer-executable instructions, when executed by the processor, perform the steps of the various functions and / or methods in the embodiments described herein.

[0063] Example 9 Based on the above embodiments, this embodiment provides an application example.

[0064] This application example relates to the field of rail transit technology, and specifically to an online status monitoring method and system for vacuum isolating contactors in permanent magnet traction systems of rail transit trains. Specifically, this invention provides an online leakage detection solution for vacuum contactor vacuum tubes based on software logic and data analysis, without requiring additional hardware.

[0065] With the advancement of the dual-carbon strategy, high-efficiency and energy-saving permanent magnet traction systems are widely used in rail transit. To ensure system safety, a vacuum isolation contactor is installed between the traction inverter and the permanent magnet traction motor to achieve electrical isolation in case of fault. The vacuum contactor relies on the vacuum environment of its vacuum tube for arc extinguishing. Once the vacuum tube leaks and the vacuum level drops, its arc extinguishing performance will deteriorate sharply, which may lead to contact erosion, system failure, or even safety accidents.

[0066] The relevant detection methods are offline, which involves periodic measurements using a dedicated vacuum level detector. This has three major drawbacks: offline operation, reliance on dedicated equipment, and poor real-time performance. In addition, while some technologies offer online monitoring solutions, they require the installation of additional physical sensors (such as miniature tensile and compressive sensors), leading to additional hardware costs, installation complexity, and potential points of failure.

[0067] Therefore, there is an urgent need in this field for a vacuum contactor vacuum status detection method that can utilize the existing train control system to achieve online, real-time, seamless detection without adding any additional hardware.

[0068] Traditional detection methods require specialized instruments, operate offline, are costly, and lack real-time performance; some online solutions require additional sensors. This application innovatively utilizes the characteristic of reduced arc-extinguishing capability due to vacuum tube leakage, leading to a delay in breaking current. It controls a contactor to execute a specific load-bearing breaking sequence via a traction control unit (TCU), and performs logical judgments based on current signals collected by existing current sensors to achieve leakage diagnosis. This application achieves fully software-based online status detection, eliminating the need for any specialized testing instruments or additional sensors, significantly reducing implementation costs and system complexity.

[0069] The status of vacuum tubes cannot be continuously and periodically monitored and sensed. This application integrates diagnostic logic into the TCU software, allowing for flexible setting of the diagnostic cycle (e.g., once a month), and automatic triggering of non-sensory detection under specific vehicle operating conditions (e.g., when the vehicle is stationary upon initial power-on). This application achieves periodic, online, automatic monitoring of the vacuum tube's vacuum status, significantly improving the real-time performance of status sensing and the safety of train operation. Faults can be detected and alerted promptly.

[0070] Related testing methods are complex or may affect normal train operation. This application designs precise timing control (such as delaying pulse generation after closure and delaying current judgment after disconnection), and the entire diagnostic process is completed within seconds (e.g., 1-2 seconds), without interfering with normal train operation. The testing process of this application is fast, convenient, and seamless, providing a good user experience and not affecting train operation efficiency.

[0071] Single-signal-source detection lacks reliability and is susceptible to misjudgments due to occasional sensor malfunctions or interference. This application introduces a UVW three-phase current comparison and verification mechanism, which cross-verifies the diagnostic results by analyzing the consistency behavior of the three-phase current after the contactor disconnects. This application upgrades the diagnosis from single-channel signal judgment to system-level multi-source information fusion judgment, greatly improving the reliability and anti-interference capability of the diagnostic results and effectively preventing false alarms.

[0072] Traditional solutions lack quantitative indicators, making it impossible to detect the gradual degradation of vacuum levels and enabling predictive maintenance. This application upgrades the simple on / off current judgment to the precise measurement and quantitative evaluation of turn-off time, using this as a core diagnostic parameter. This application achieves quantitative diagnosis of the vacuum tube's health status, not only determining whether a fault has occurred but also sensing when a fault will occur through trends in turn-off time, providing a data foundation for predictive maintenance.

[0073] Fixed diagnostic thresholds are difficult to adapt to all operating conditions and individual device differences, and the system lacks self-optimization capabilities. This application constructs a big data-based cumulative analysis module that optimizes diagnostic thresholds through self-learning from historical data and performs long-term trend monitoring and early warning for the turn-off time of the same contactor. This application enables the system to have adaptive and intelligent capabilities, with diagnostic accuracy continuously improving as data accumulates. It also represents a technological leap from post-event alarms to pre-event warnings, significantly improving operational safety and economy.

[0074] Existing online monitoring solutions (such as induction coils and photoelectric sensors) require the addition of dedicated hardware, resulting in high costs, complex modifications, and unsuitability for rail transit vehicles where alteration of wiring harnesses is strictly prohibited. This application pioneers an online monitoring concept without adding any hardware, fully utilizing the existing TCU and three-phase current sensors in the traction system, and implementing functionality through innovative software logic. This application reduces hardware costs to zero, requires no hardware modifications to the vehicle, and is highly economical and versatile, particularly suitable for fields such as rail transit where the stability of existing systems is extremely critical.

[0075] Most existing solutions rely on passive monitoring, depending on the characteristics of the equipment during normal operation. They cannot perform on-demand diagnostics when the vehicle is stationary, resulting in insufficient real-time performance and coverage. This application designs an active diagnostic mechanism led by the TCU, which can automatically trigger an independent and safe diagnostic load disconnection sequence when the vehicle is powered on while stationary. This application achieves on-demand, periodic, and non-intrusive detection, independent of operating conditions, with extremely high diagnostic coverage and real-time performance, and the process is controllable and safe.

[0076] Existing electrical signal monitoring schemes (such as waveform correlation analysis) have poor anti-interference capabilities, are prone to misjudgment, and lack quantitative indicators, making it impossible to detect gradual degradation. This application proposes using turn-off time as the core quantitative diagnostic parameter and introduces three-phase current consistency for cross-validation, constructing a diagnostic model of quantitative measurement + multi-source verification. This application's diagnosis moves from qualitative to quantitative, significantly improving accuracy and reliability. It also provides traceable quantitative indicators for state prediction.

[0077] Existing solutions can only provide fault alarms, but cannot predict health status, resulting in an outdated maintenance model. This application integrates big data analytics to achieve self-learning optimization of diagnostic thresholds and trend prediction of vacuum tube health status. This application endows the system with intelligent features, upgrading the maintenance model from preventative to predictive, enabling early detection of potential problems, minimizing operational interruptions, and improving safety.

[0078] The core of this invention lies in creatively distinguishing and utilizing the significant difference in arc extinguishing time (turn-off time) when a vacuum contactor interrupts load current under normal and vacuum leakage conditions. By controlling the contactor to execute a standardized diagnostic load-bearing interruption sequence through a traction control unit (TCU), and based on existing three-phase current sensor signals, multi-dimensional and highly reliable online diagnostics are achieved. Furthermore, this invention achieves self-optimization of diagnostic thresholds and trend prediction of vacuum tube health status through historical data accumulation and analysis. This invention actively controls and observes this phenomenon through the traction control unit (TCU).

[0079] System Composition: The system described in this invention mainly relies on existing train equipment, including: 1. Traction Control Unit (TCU): As the core controller, it is used to execute all control logic, diagnostic algorithms, and data analysis.

[0080] 2. Vacuum isolation contactor: The object being diagnosed.

[0081] 3. Current sensor (such as a three-phase current sensor for motor): used to collect the current of the three-phase circuits U, V, and W, and is an existing sensor.

[0082] 4. Display / Alarm Unit: Used to output diagnostic results and early warning information to maintenance personnel.

[0083] 5. Data storage unit: Used to store historical diagnostic data (for big data analysis).

[0084] Implementation conditions and diagnostic logic: The online status detection method includes the following steps: 1. Triggering conditions: a. The system automatically generates a diagnostic start flag according to a preset cycle (e.g., every month).

[0085] b. The triggering of the diagnostic start flag requires the simultaneous fulfillment of the following safety conditions: the train is powered on for the first time, the high-speed circuit breaker is in the closed state, the vehicle is stationary, and the intermediate support capacitor voltage is greater than, for example, 1000V; 2. Current build-up and contactor disconnection: a. After receiving the diagnostic flag, the traction control unit (TCU) closes the vacuum isolation contactor of the target shaft.

[0086] b. After confirming that the vacuum isolating contactor is reliably closed, after a delay of T1 (e.g., 100ms), the TCU sends a pulse voltage command with a duration of T2 (e.g., 1s) and a preset frequency (e.g., 50Hz) to the traction inverter, thereby establishing a three-phase current with stable amplitude in the motor circuit.

[0087] c. After a delay of T3 (e.g., 200ms, to ensure current has been established) after the pulse is first issued, the TCU issues a disconnect command to instruct the isolation contactor to disconnect. The exact moment when the disconnect command is issued is recorded as the preset disconnect time T_break.

[0088] 3. Status assessment and fault diagnosis: a. After detecting that the isolating contactor has indeed switched to the disconnected state, start the high-precision timer and simultaneously monitor the current values ​​of the three phases U, V, and W.

[0089] b. Turn-off Time Calculation: Calculate the time required for the three-phase current to decrease from the moment the break command is issued (T_break) to the preset current threshold (I_th, e.g., 10A), denoted as the U-phase fall time (T_u), V-phase fall time (T_v), and W-phase fall time (T_w). Take the maximum value among the three as the turn-off time (T_off) for this diagnosis. That is: T_off = max(T_u, T_v, T_w).

[0090] c. Multi-dimensional diagnostic logic: - Main criterion: If the turn-off time T_off is greater than the preset time fault threshold T_fault (e.g., 20ms), it is preliminarily determined that the vacuum tube of the vacuum isolation contactor has leaked.

[0091] - Auxiliary Verification (Three-Phase Consistency Verification): Under the above premise, if the current in two or more of the three phases (U, V, and W) persists after the disconnection (i.e., the duration of each phase is significantly greater than the normal value), then the vacuum tube leakage fault of the vacuum isolation contactor is finally confirmed. This verification can effectively eliminate false alarms caused by momentary faults of single-phase sensors.

[0092] 4. Troubleshooting: Once the diagnostic logic confirms a vacuum tube leak, the TCU immediately generates a high-level fault code and reports it in real time to the cab display and the ground maintenance center via the vehicle network, clearly indicating that the vacuum tube of the XX axis isolating contactor is leaking and requesting immediate inspection and replacement.

[0093] Meanwhile, all relevant data from this diagnosis (including turn-off time T_off, U-phase fall time T_u, V-phase fall time T_v, W-phase fall time T_w, three-phase current waveform segments, etc.) were packaged and stored.

[0094] 5. Big Data Analysis and Adaptive Optimization: Data accumulation: The system stores the shutdown time T_off data, corresponding contactor number, and running mileage of each diagnosis into the historical database.

[0095] Threshold self-learning: The system periodically analyzes the distribution of the turn-off time T_off data of a large number of normal contactors, automatically calculates and updates the time fault threshold T_fault, so that it is more in line with the actual vehicle operating conditions and device aging characteristics, and achieves continuous optimization of diagnostic accuracy.

[0096] Trend prediction and predictive maintenance: The system performs linear regression or trend analysis on the turn-off time T_off values ​​of the same contactor over time. If a continuous and statistically significant upward trend is found in the turn-off time T_off, even if its absolute value has not yet exceeded the time fault threshold T_fault, the system can issue an early warning that the vacuum level is deteriorating, thereby achieving predictive maintenance and preventing problems before they occur.

[0097] 6. Fault diagnosis method based solely on the fall time of phase U (T_u), phase V (T_v), and phase W (T_w) This embodiment provides a fault prediction method that uses the fall times (T_u, T_v, T_w) of phases U, V, and W acquired in a single data acquisition as the sole basis, and regards the minimum and second minimum values ​​as normal benchmarks, without relying on historical data. The method includes: First, sort T_u, T_v, and T_w by numerical value to obtain three values ​​arranged from smallest to largest. The smallest value (T_min) and the middle value (T_sub) are normal values, and the largest value is the monitored object (T_max).

[0098] Next, the absolute deviation (D_abs) and relative deviation (D_rel) are calculated. The absolute deviation (D_abs) is T_max minus T_min, reflecting the absolute duration for which the maximum value exceeds the normal benchmark. The relative deviation (D_rel) is the ratio (converted to a percentage) of the absolute deviation D_abs to the normal benchmark T_min, eliminating the influence of the benchmark size itself on the deviation judgment.

[0099] Finally, the warning level is determined based on the characteristics of the indicators: A Level 1 warning (potential degradation) corresponds to a relative deviation D_rel between, for example, 15% and 30%, indicating that the maximum value has begun to deviate, and the next diagnosis should focus on the phase corresponding to T_max; The Level 2 warning (significant deterioration) corresponds to a relative deviation D_rel between 30% and 50%, indicating that the arc extinguishing performance of the phase corresponding to T_max has significantly decreased and there is a moderate risk of leakage. A Level 3 early warning (proximate fault / deteriorated) indicates a relative deviation D_rel of at least 50%, signifying a significant leak in the vacuum tube and a severe decrease in its arc-extinguishing capability, requiring immediate inspection and replacement. The original phase corresponding to T_max can be directly located through the sorting results, clearly identifying the location of the abnormal phase.

[0100] In some implementations, a normal baseline mean (T_ref), which is the average of T_min and T_sub, can be calculated to smooth fluctuations in a single baseline and represent the current normal arc extinguishing level. Then, the normal baseline mean (T_ref) is used instead of T_min in the above implementations for fault diagnosis.

[0101] In some implementations, a Level 1 warning can be: D_rel∈[15%,30%) and D_abs≤3ms; a Level 2 warning can be: D_rel∈[30%,50%) and D_abs≥5ms; a Level 3 warning can be: D_rel≥50% or D_abs≥10ms.

[0102] Compared with related technologies, this invention has fundamental differences and significant progress: The technical approach is different: Compared to solutions that require the addition of dedicated sensors, this invention is a pure methodological and software innovation that achieves advanced functions by exploring and utilizing the signal and control potential of existing systems.

[0103] The diagnostic dimensions and precision differ: most related solutions rely on a single threshold judgment. This invention introduces precise measurement of turn-off time and cross-validation of three-phase current, elevating the diagnosis from qualitative to quantitative, and from a single point to a system, thus greatly improving reliability.

[0104] The level of intelligence differs: This invention uniquely incorporates big data accumulation and self-learning mechanisms, enabling the system to have the ability to self-optimize and predict health, which is completely lacking in related technologies and represents the development direction of condition monitoring technology.

[0105] This application achieves the following beneficial effects: Extremely high cost-effectiveness: Hardware costs are close to zero, achievable solely through software upgrades, resulting in extremely low modification and deployment costs. Superior diagnostic reliability: Based on three-phase current comparison and quantitative analysis of turn-off time, a multi-verification mechanism is constructed to minimize false alarms and missed alarms. Proactive predictive capability: Through trend analysis, a leap from post-fault alarm to pre-fault early warning is achieved, significantly improving operational safety and maintenance planning. Online, real-time, and seamless operation: The entire process is completed automatically without affecting normal train operation, achieving periodic and automated health management of vacuum tube status. Adaptability and intelligence: The system can continuously self-optimize through data-driven processes, maintaining long-term diagnostic accuracy and possessing a high degree of intelligence.

[0106] In this embodiment, TCU is the traction control unit. The turn-off time (T_off) is the time elapsed from the moment the contactor disconnection command is issued until the current in the last phase of the circuit drops below a set threshold. Predictive maintenance is a maintenance activity proactively planned and executed before a fault occurs, based on real-time monitoring and trend analysis of equipment status.

[0107] In the embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0108] It should be noted that, in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element limited by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0109] While the embodiments disclosed in this invention are as described above, the above content is merely for the purpose of facilitating understanding of this invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed in this invention; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A contactor condition monitoring method, characterized in that, include: Step S02: After the vacuum isolating contactor is closed, a three-phase current is established, and after a preset delay, a disconnection command for disconnecting the vacuum isolating contactor is issued, and the disconnection time is recorded. Step S03: Obtain the time it takes for the three-phase current value to drop from the interruption time to a preset current threshold. Step S04: Based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, determine whether the vacuum tube of the vacuum isolation contactor is leaking.

2. The method according to claim 1, characterized in that, The method further includes: Step S01: Based on meeting safety conditions, generate a diagnostic start flag, which is used to start the contactor status monitoring; The safety conditions include: the train being powered on for the first time, the high-speed circuit breaker being in a closed state, the vehicle being stationary, and the intermediate support capacitor voltage being greater than a preset value.

3. The method according to claim 1, characterized in that, The method further includes: Step S05: If a vacuum tube leak is confirmed, a fault code is generated and reported to the cab display and the ground maintenance center, and the diagnostic data is stored.

4. The method according to claim 1, characterized in that, Step S04, based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, determines whether the vacuum tube of the vacuum isolation contactor is leaking, including: Step S041: Take the maximum value among the U-phase fall time, V-phase fall time, and W-phase fall time as the turn-off duration; Step S042: If the shutdown duration exceeds a preset fault threshold, a leak is preliminarily determined.

5. The method according to claim 4, characterized in that, Step S04, which determines whether the vacuum tube of the vacuum isolating contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, further includes: Step S043: If the duration of two or more of the phases U-phase fall time, V-phase fall time, and W-phase fall time exceeds the preset fault threshold, then a leak is confirmed.

6. The method according to claim 1, characterized in that, Step S04, based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold, determines whether the vacuum tube of the vacuum isolation contactor is leaking, including: Sort the fall time of phase U, phase V, and phase W by numerical value to obtain the maximum and minimum fall times. The absolute deviation and relative deviation are calculated based on the maximum and minimum descent times. The absolute deviation is the maximum descent time minus the minimum descent time, and the relative deviation is the ratio of the absolute deviation to the minimum descent time. Determine whether the vacuum tube is leaking based on the numerical range of the relative deviation.

7. A contactor condition monitoring device, characterized in that, include: The test module is used to establish a three-phase current after the vacuum isolating contactor is closed, issue a disconnection command for the vacuum isolating contactor to disconnect after a preset delay, and record the disconnection time. The data acquisition module is used to obtain the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold. The leakage detection module is used to determine whether the vacuum tube of the vacuum isolation contactor is leaking based on the time it takes for the three-phase current value to drop from the breaking time to a preset current threshold.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

9. An electronic device comprising a processor and a memory, characterized in that, The memory stores a computer program, and the processor executes the computer program to implement the method of any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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