An intelligent operation and maintenance method and system of a low-voltage draw-out switch cabinet, a medium and a product

Abstract

The application provides an intelligent operation and maintenance method and system of a low-voltage draw-out switch cabinet, a medium and a product, and relates to the technical field of intelligent operation and maintenance of electrical equipment. The method comprises the following steps: in the handcart operation process of the low-voltage draw-out switch cabinet, displacement data and operating torque data of the handcart are synchronously collected, and time correlation processing is performed to obtain a correlation data sequence; torque gradient analysis is performed on the correlation data sequence to determine a characteristic position point of torque mutation; the displacement range of electrical contact of the contact is determined according to the mechanical structure parameters of the handcart, and when the characteristic position point is located in the range, the operating torque reference value and the contact resistance torque value are obtained from the correlation data sequence; the contact contact abnormality degree is obtained according to the deviation comparison result of the two, and abnormal pre-control operation is performed accordingly. The technical problem of poor fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet in the related art is solved, and the technical effect of improving the fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent operation and maintenance of electrical equipment, and particularly relates to an intelligent operation and maintenance method and system for a low-voltage draw-out switch cabinet, a medium and a product. BACKGROUND

[0002] The low-voltage draw-out switch cabinet is a widely used power distribution equipment in the power system, and electrical connection is achieved by inserting the movable contact and the static contact seat between the handcart and the cabinet. The contact connection part is the key part most prone to overheating failure during the operation of the switch cabinet because of the long-term bearing of working current and the existence of contact resistance. During the operation of drawing out and inserting the handcart, the contact resistance is prone to deterioration due to factors such as rail wear, uneven operation torque, and changes in the surface state of the contact, which further leads to continuous overheating of the contact during subsequent operation, and even causes contact ablation or fire in the cabinet.

[0003] In the related art, in order to solve the above technical problems, a switch cabinet contact temperature online monitoring method based on a wireless temperature sensor is proposed, that is, a wireless temperature sensor is installed near the static contact seat to continuously collect contact temperature data, and a temperature threshold comparison and over-temperature alarm strategy is used to realize the timely discovery of contact overheating failure. Specifically, temperature real-time collection in the normal operation stage, graded alarm push in the early warning stage, and linkage tripping protection in the failure stage, thereby shortening the fault discovery time and reducing the accident loss to a certain extent.

[0004] However, the above-mentioned contact temperature online monitoring method only initiates an alarm when the contact temperature is abnormal, and cannot actively identify mechanical abnormalities that cause poor contact during the operation of the handcart, so it is difficult to intervene in the early stage of failure, and thus the fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet in the related art is poor. SUMMARY

[0005] The present application provides an intelligent operation and maintenance method, system, medium and product for a low-voltage draw-out switch cabinet, which can improve the fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet.

[0006] In a first aspect, the application provides an intelligent operation and maintenance method of a low-voltage draw-out switch cabinet, which is applied to the intelligent operation and maintenance system. The method comprises: in the process of operating a handcart of the low-voltage draw-out switch cabinet, collecting displacement data of the handcart in real time through a displacement sensor arranged on a guide rail of the handcart, and synchronously collecting operating torque data through a torque sensor arranged on a handcart operating mechanism; performing time correlation processing on the displacement data and the operating torque data to obtain a correlation data sequence, the correlation data sequence representing operating torque values of the handcart at different displacement positions; performing torque gradient analysis on the correlation data sequence to obtain torque change gradient values at the displacement positions, and marking a displacement position with a torque change gradient value exceeding a target gradient threshold as a feature position point; determining a displacement range in which initial electrical contact between a moving contact of the handcart and a static contact seat of a cabinet body occurs according to mechanical structure parameters of the handcart, and in the case that the feature position point is determined to be located within the displacement range, determining an initial contact position point matching a starting displacement position of the displacement range from the correlation data sequence, taking an operating torque value of the initial contact position point as an operating torque reference value, and determining an operating torque value of the feature position point in the correlation data sequence as a contact resistance torque value; performing deviation comparison analysis on the contact resistance torque value and the operating torque reference value to obtain a contact abnormality degree, the contact abnormality degree representing a degree of deviation of mechanical cooperation between the moving contact of the handcart and the static contact seat of the cabinet body; and performing abnormal pre-control operation on the low-voltage draw-out switch cabinet according to the contact abnormality degree.

[0007] By adopting the above technical solution, displacement data and operating torque data are synchronously collected in the process of operating the handcart, the corresponding relationship between displacement and torque is established through time correlation processing, and the feature position point at which operating torque suddenly changes is identified through torque gradient analysis. Further, whether the torque abnormality is related to contact is determined by judging whether the feature position point is located within the displacement range of electrical contact of the contact, and the contact abnormality degree is obtained by comparing the contact resistance torque value and the operating torque reference value, so that the contact cooperation abnormality can be actively identified in the handcart operation stage without waiting for the contact temperature to become abnormal before initiating an alarm. Thus, the technical problem of poor fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet in the related art is solved, and the technical effect of improving the fault pre-control performance in the operation and maintenance process of the low-voltage draw-out switch cabinet is achieved.

[0008] Optionally, the displacement data and operating torque data are time-correlated to obtain a correlated data sequence. Specifically, this includes: acquiring the displacement sampling timestamp sequence of the displacement sensor and the torque sampling timestamp sequence of the torque sensor. The displacement sampling timestamp sequence includes the first timestamp corresponding to each displacement sampling moment, and the torque sampling timestamp sequence includes the second timestamp corresponding to each torque sampling moment; performing clock synchronization verification on the displacement sensor and torque sensor to obtain the clock offset between the first and second timestamps; comparing the clock offset with a preset synchronization tolerance threshold, and when the clock offset is greater than the preset synchronization tolerance threshold, using the clock offset to perform clock compensation correction on the torque sampling timestamp sequence to obtain a target torque sampling timestamp sequence that is clock-synchronized with the displacement sampling timestamp sequence; traversing each first timestamp in the displacement sampling timestamp sequence and performing the following steps on the currently traversed first timestamp: in the target... The process involves finding a third timestamp in the torque sampling timestamp sequence whose time difference with the target timestamp satisfies a preset time matching condition. The target timestamp is the first timestamp currently traversed in the displacement sampling timestamp sequence. The time difference is compared with a preset matching time threshold. When the time difference is less than or equal to the preset matching time threshold, the operating torque value corresponding to the third timestamp is matched with the displacement position corresponding to the target timestamp to obtain a first associated data pair. When the time difference is greater than the preset matching time threshold, linear interpolation is performed on the operating torque values ​​corresponding to the two fourth timestamps adjacent to the target timestamp in the target torque sampling timestamp sequence to obtain the operating torque value corresponding to the target timestamp. The operating torque value is matched with the displacement position corresponding to the target timestamp to obtain a second associated data pair. The first and / or second associated data pairs are then combined to generate an associated data sequence.

[0009] By adopting the above technical solution, clock deviation between displacement sensor and torque sensor is eliminated through clock synchronization verification. Based on the time difference, a precise correspondence between displacement data and torque data is established by direct matching or linear interpolation. This ensures that the associated data sequence can accurately reflect the actual operating torque value of the handcart at each displacement position, providing a reliable data foundation for subsequent torque gradient analysis and avoiding data misalignment caused by asynchronous sensor sampling.

[0010] Optionally, torque gradient analysis is performed on the associated data sequence to obtain the torque change gradient value at each displacement position, and the displacement positions where the torque change gradient value exceeds the target gradient threshold are marked as feature position points. Specifically, this includes: extracting multiple displacement sampling points from the associated data sequence according to a preset displacement sampling interval, and obtaining the operating torque value corresponding to each displacement sampling point; establishing a displacement window with the displacement position of each displacement sampling point as the window center position and a preset window displacement amount as the window length, and extracting a torque data subsequence from the displacement window of each displacement sampling point; performing local linear fitting processing on the torque data subsequence to obtain the fitted torque slope at each displacement sampling point, and using the fitted torque slope as the torque change gradient value at each displacement sampling point; and obtaining the torque change gradient value when the handcart slides along the handcart guide rail in an unloaded state. The historical torque fluctuation range is determined, and the torque fluctuation reference bandwidth of the handcart is determined based on the historical torque fluctuation range. The torque fluctuation reference bandwidth is multiplied by the preset safety margin coefficient to obtain the target gradient threshold. The torque change gradient value of each displacement sampling point is compared with the target gradient threshold. When there is a target displacement sampling point among multiple displacement sampling points whose absolute value of torque change gradient value is greater than the target gradient threshold, the target displacement sampling point is marked as a torque mutation candidate point. The displacement continuous distribution analysis is performed on the torque mutation candidate points. When there are multiple candidate displacement points continuously distributed among the torque mutation candidate points, the target candidate displacement point that meets the preset torque change gradient condition among the multiple candidate displacement points is determined as the feature position point. When the torque mutation candidate point is an isolated single candidate displacement point, the single candidate displacement point is determined as the feature position point.

[0011] By adopting the above technical solution, the gradient value of torque change at each displacement position is calculated by using a sliding window and local linear fitting. The target gradient threshold is dynamically determined based on the historical torque fluctuation range under the unloaded state of the handcart, thereby enabling adaptive identification of torque mutation points that exceed the normal fluctuation range. At the same time, by performing continuous distribution analysis on torque mutation candidate points, it is possible to distinguish between isolated single-point anomalies and continuous regional anomalies, thereby improving the accuracy and reliability of feature location point identification.

[0012] Optionally, the displacement range for initial electrical contact between the moving contact of the trolley and the stationary contact seat of the cabinet is determined based on the mechanical structural parameters of the trolley. Specifically, this includes: obtaining the mechanical structural parameters of the trolley from the equipment file of the low-voltage withdrawable switchgear, including the trolley's total travel length, the moving contact's extension length, and the designed contact engagement stroke; determining the first trolley displacement value when the front end of the moving contact reaches the insertion point of the stationary contact seat based on the trolley's total travel length and the moving contact's extension length, and using this first trolley displacement value as the initial electrical contact starting displacement; and comparing the initial electrical contact starting displacement with the designed contact engagement stroke. The two values ​​are added together to obtain the second handcart displacement value when the moving contact of the handcart is fully engaged with the stationary contact seat of the cabinet. This second handcart displacement value is used as the initial electrical contact termination displacement. The cumulative number of uses and historical wear detection records of the handcart guide rail are obtained, and the guide rail wear compensation amount of the handcart is determined based on the cumulative number of uses and historical wear detection records. The initial electrical contact start displacement and initial electrical contact termination displacement are adjusted using the guide rail wear compensation amount to obtain the target electrical contact start displacement and target electrical contact termination displacement. The displacement interval between the target electrical contact start displacement and the target electrical contact termination displacement is determined as the displacement range.

[0013] By adopting the above technical solution, the theoretical displacement range of the moving contact and the stationary contact seat that make electrical contact is accurately calculated based on the mechanical structural parameters of the handcart. The guide rail wear compensation is then performed based on the cumulative number of uses and historical wear detection records, thereby obtaining the target displacement range that matches the actual working conditions. This ensures that the correlation judgment between the characteristic position point and the contact process is accurate and reliable, and avoids misjudgment caused by displacement range deviation due to guide rail wear.

[0014] Optionally, an abnormality pre-control operation is performed on the low-voltage withdrawable switchgear based on the contact anomaly degree, specifically including: performing a second numerical comparison analysis between the contact anomaly degree and a first preset threshold, so that when the contact anomaly degree is greater than the first preset threshold, it is determined that the moving contact of the trolley is in a contact deterioration state, and a contact contact state deterioration warning message is generated; determining the total number of feature position points in the associated data sequence, determining the displacement coordinate distribution range of the feature position points based on the total number and the actual position coordinates of the feature position points, and determining the coverage ratio of the displacement coordinate distribution range to the full stroke length of the trolley; averaging the torque change gradient values ​​at the feature position points to obtain the average torque change gradient; and comparing the total number with the second preset threshold. The threshold is used for quantity comparison analysis to obtain the quantity comparison analysis results. The coverage ratio is compared with the preset ratio threshold to obtain the ratio comparison analysis results. The average value of the torque change gradient is compared with the preset gradient threshold to obtain the gradient comparison analysis results. If the total quantity is greater than the second preset threshold according to the quantity comparison analysis results, the coverage ratio is greater than the preset ratio threshold according to the ratio comparison analysis results, and the average value of the torque change gradient is greater than the preset gradient threshold according to the gradient comparison analysis results, the wear degree of the guide rail of the handcart is determined to be abnormal wear. Otherwise, the wear degree of the guide rail is determined to be normal wear. An abnormal pre-control operation is performed on the low-voltage withdrawable switchgear according to the wear degree of the guide rail.

[0015] By adopting the above technical solution, the contact status of the contact is determined by comparing the contact anomaly degree with the first preset threshold. At the same time, the wear degree of the guide rail is comprehensively evaluated by analyzing three dimensions: the total number of characteristic location points, the coverage ratio of the distribution range, and the average value of the torque change gradient. This enables a dual diagnosis of contact problems and guide rail wear problems, providing a precise decision-making basis for subsequent differentiated operation and maintenance measures.

[0016] Optionally, abnormal pre-control operations are performed on the low-voltage withdrawable switchgear based on the degree of guide rail wear. Specifically, this includes: acquiring contact temperature data collected by a wireless temperature sensor located at the stationary contact seat of the cabinet, and determining the temperature rise rate of the moving contact of the trolley based on the contact temperature data; performing a time-series correlation analysis between the temperature rise rate and the contact contact anomaly to obtain a comprehensive contact degradation index; generating differentiated operation and maintenance instructions based on the comprehensive contact degradation index and the degree of guide rail wear, wherein: a contact maintenance instruction is generated when the comprehensive contact degradation index is greater than a third preset threshold and the guide rail wear is normal; a guide rail repair instruction is generated when the comprehensive contact degradation index is less than or equal to the third preset threshold and the guide rail wear is abnormal; and a combined operation and maintenance instruction including both contact maintenance and guide rail repair instructions is generated when the comprehensive contact degradation index is greater than the third preset threshold and the guide rail wear is abnormal; and performing abnormal pre-control operations on the low-voltage withdrawable switchgear based on the differentiated operation and maintenance instructions.

[0017] By adopting the above technical solution, the abnormal contact degree of the contact detected during the operation of the handcart is correlated with the temperature rise rate collected during the operation phase through time-series analysis. This yields a comprehensive contact deterioration index that reflects the degree of contact deterioration. Combined with the degree of guide rail wear, differentiated operation and maintenance instructions are generated. This allows for targeted pre-control measures to be taken according to different fault types and severity, avoiding a one-size-fits-all, extensive operation and maintenance approach and improving the utilization efficiency of operation and maintenance resources.

[0018] Optionally, abnormal pre-control operations are performed on the low-voltage withdrawable switchgear according to differentiated operation and maintenance instructions. Specifically, this includes: under a contact maintenance instruction, determining the target allowable current capacity of the trolley based on the comprehensive contact deterioration index, where the target allowable current capacity is negatively correlated with the comprehensive contact deterioration index; limiting the actual operating current of the trolley to within the target allowable current capacity by adjusting the trip parameters of the upstream circuit breaker of the low-voltage withdrawable switchgear; activating a wireless temperature sensor to monitor the temperature of the trolley's moving contacts in real time, and reducing the target allowable current capacity to the secondary current limiting threshold when the temperature rise rate of the moving contacts exceeds the preset safety rate; generating a contact maintenance task work order based on the comprehensive contact deterioration index, the target allowable current capacity, and the temperature rise rate, and pushing the contact maintenance task work order to the operation and maintenance terminal; under a rail inspection instruction, determining the current position of the trolley and determining the safe range of allowable displacement of the trolley based on its current position and the degree of rail wear; and determining the safe range of allowable displacement of the trolley based on the current position of the trolley and the degree of rail wear; and determining the current position as... When in the working position, disable the remote opening and closing function of the circuit breaker while retaining the local manual opening and closing function, and activate the enhanced locking mode through the electromagnetic lock in the locking mechanism of the circuit breaker; when the current position is determined to be a test position or an isolation position, disable all pushing operations of the circuit breaker; generate a rail maintenance task order based on the rail wear level, the current position, and the safe position range, and push the rail maintenance task order to the operation and maintenance terminal; under the combined operation and maintenance command, switch the operation mode of the low-voltage withdrawable switchgear to the emergency protection mode; in the emergency protection mode, reduce the target allowable current capacity to the emergency protection capacity limit; disable the remote pushing and pulling operation of the circuit breaker and the local pushing and pulling operation, and switch the temperature sampling frequency of the moving contact and the position sampling frequency of the circuit breaker to the high-frequency sampling mode; generate a comprehensive task order based on the contact deterioration comprehensive index, rail wear level, emergency protection capacity limit, and high-frequency sampling mode, and push the comprehensive task order to both the operation and maintenance terminal and the operation and maintenance management center.

[0019] By adopting the above technical solutions, specific abnormal pre-control operations are executed according to different types of differentiated operation and maintenance instructions, including current limiting protection and enhanced temperature monitoring under contact maintenance instructions, position locking and operation disabling under guide rail maintenance instructions, and emergency protection mode switching and high-frequency sampling monitoring under combined operation and maintenance instructions. This ensures that the equipment operation risk is controlled within an acceptable range before operation and maintenance personnel arrive on site to handle the problem, achieving proactive pre-control of faults rather than passive response.

[0020] Secondly, embodiments of this application provide an intelligent operation and maintenance system, which includes: one or more processors and a memory; the memory is coupled to one or more processors, and the memory is used to store computer program code, the computer program code including computer instructions, and one or more processors call the computer instructions to cause the intelligent operation and maintenance system to perform the method described in the first aspect and any possible implementation thereof.

[0021] Thirdly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on an intelligent operation and maintenance system, cause the intelligent operation and maintenance system to execute the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on an intelligent operation and maintenance system, cause the intelligent operation and maintenance system to perform the method described in the first aspect and any possible implementation thereof. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating an intelligent operation and maintenance method for low-voltage withdrawable switchgear in an embodiment of this application.

[0024] Figure 2 This is a schematic diagram of the physical device structure of an intelligent operation and maintenance system in the embodiments of this application. Detailed Implementation

[0025] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to any or all possible combinations including one or more of the listed items.

[0026] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0027] This application provides an intelligent operation and maintenance method for low-voltage withdrawable switchgear, see reference. Figure 1 , Figure 1 This is a flowchart illustrating an intelligent operation and maintenance method for low-voltage withdrawable switchgear in this application embodiment, including the following steps:

[0028] Step S101: During the operation of the handcart of the low-voltage withdrawable switchgear, the displacement data of the handcart is collected in real time by the displacement sensor set on the handcart guide rail, and the operating torque data is collected synchronously by the torque sensor set on the handcart operating mechanism.

[0029] In the above embodiments, the low-voltage withdrawable switchgear is an electrical device widely used in industrial power distribution systems. Its core structure includes a fixedly installed cabinet and a withdrawable trolley. The trolley carries electrical components such as circuit breakers and achieves electrical connection or disconnection with the cabinet by sliding along guide rails inside the cabinet. The electrical connection between the trolley and the cabinet is achieved through the insertion and engagement of a moving contact and a stationary contact seat. The moving contact is fixedly installed on the trolley and moves with it, while the stationary contact seat is fixedly installed inside the cabinet and electrically connected to the main busbar. The displacement sensor can be a magnetostrictive linear displacement sensor, with a measurement accuracy of 0.1 mm and a measurement range covering the entire stroke length of the trolley. The displacement sensor is installed at the fixed end of the trolley guide rail and determines the real-time displacement of the trolley by detecting the position of the magnetic ring connected to the trolley. The torque sensor can be a strain gauge torque sensor, installed on the drive shaft of the trolley operating mechanism, used to detect the operating torque applied by the operator when pushing the trolley. Its measurement range can be set to 0 to 100 Nm, with a sampling accuracy of 0.5 Nm.

[0030] In the above embodiment, a certain model of MNS low-voltage withdrawable switchgear is used as an example. The total travel length of the switchgear trolley is 350 mm, of which the travel from the disconnect position to the test position is approximately 200 mm, and the travel from the test position to the working position (i.e., the connection position) is approximately 150 mm. The designed engagement travel between the trolley's moving contact and the cabinet's stationary contact seat is 60 mm, meaning that the trolley needs to move 60 mm from the moment the front end of the moving contact contacts the entrance of the stationary contact seat until full engagement. When the operator performs the trolley insertion operation, the intelligent operation and maintenance system starts the data acquisition program. The displacement sensor records the trolley's displacement data in real time at a sampling frequency of 100 times per second, and the torque sensor synchronously records the operating torque data at a sampling frequency of 200 times per second. Assuming that the duration of this insertion operation is 8 seconds, the displacement sensor collects 800 displacement sampling points, and the torque sensor collects 1600 torque sampling points. The displacement data is presented as an increasing sequence from 0 mm (separation position) to 350 mm (connection position), with the rate of change depending on the operator's pushing speed. The operating torque data is presented as a fluctuating numerical sequence that changes with the movement of the handcart. Under normal circumstances, the operating torque is relatively stable during the guide rail sliding phase, mainly overcoming the friction of the guide rail and the weight of the handcart itself, with a typical value in the range of 15 to 25 Nm. However, during the contact phase, the operating torque increases significantly because the moving contact needs to overcome the elastic clamping force of the stationary contact seat to complete engagement, with a typical value reaching 35 to 50 Nm. This data acquisition method enables full monitoring of the handcart operation process, rather than just monitoring the static state of the handcart after it reaches a specific position, thus capturing dynamic anomalies during handcart operation.

[0031] Step S102: Perform time correlation processing on the displacement data and the operating torque data to obtain a correlation data sequence. The correlation data sequence represents the operating torque value of the handcart at different displacement positions.

[0032] In the above embodiment, since the sampling frequency of the displacement sensor is 100 Hz and the sampling frequency of the torque sensor is 200 Hz, their sampling times are not completely synchronized. Therefore, time correlation processing is needed to unify the two sets of data to the same time reference. Taking the aforementioned handcart insertion operation as an example, the displacement sensor collects 800 displacement sampling points within 8 seconds, each sampling point containing a timestamp of the sampling time and the corresponding displacement value; the torque sensor collects 1600 torque sampling points within 8 seconds, each sampling point containing a timestamp of the sampling time and the corresponding torque value. The time correlation processing uses the displacement sampling timestamp as the reference, traversing the 800 displacement sampling points, and finding the torque value with the closest time among the 1600 torque sampling points for each displacement sampling point for pairing. When the time difference is large, the torque value at the corresponding time is calculated by linear interpolation of two adjacent torque sampling points. After time correlation processing, a correlated data sequence containing 800 displacement-torque data pairs is generated. The following is a partial data example of the associated data sequence: {(0.0mm, 18.5N·m), (3.5mm, 19.2N·m), (7.1mm, 18.8N·m), ..., (175.6mm, 22.3N·m), (178.5mm, 22.7N·m), ..., (278.9mm, 24.8N·m), (286.0mm, 48.6N·m), ..., (350.0mm, 35.6N·m)}. This associated data sequence covers the entire travel of the handcart from 0 mm (separation position) to 350 mm (connection position).

[0033] Step S103: Perform torque gradient analysis on the associated data sequence to obtain the torque change gradient value at each displacement position, and mark the displacement position where the torque change gradient value exceeds the target gradient threshold as the feature position point;

[0034] In the above embodiment, torque gradient analysis is performed on the generated associated data sequence to identify displacement locations where the operating torque abruptly changes. 351 displacement sampling points (0 mm, 1 mm, ..., 350 mm) are extracted from the associated data sequence at 1 mm displacement sampling intervals. For each displacement sampling point, a 10 mm displacement window is established centered on that point, and the torque change gradient value is calculated by fitting the data points within the window. Taking the displacement position of 150 mm as an example, the displacement window ranges from 145 mm to 155 mm. The torque data within the window, after least squares fitting, yields a torque change gradient value of 0.037 Nm / mm. This value is much smaller than the target gradient threshold of 0.30 Nm / mm (obtained by multiplying the torque fluctuation baseline bandwidth of 0.15 Nm / mm determined from the historical unloaded data of the handcart by a safety margin factor of 2.0), indicating that the torque change near this location is gradual. At the displacement position of 286 mm, the displacement window ranges from 281 mm to 291 mm. The torque data within the window, after fitting, yields a torque change gradient value of 0.61 Nm / mm, which exceeds the target gradient threshold of 0.30 Nm / mm. Furthermore, there are 5 consecutive candidate points for torque abrupt changes within the range of 284 mm to 288 mm. The 286 mm point with the largest gradient value is selected as the feature location point.

[0035] Step S104: Determine the displacement range of the initial electrical contact between the moving contact of the handcart and the stationary contact seat of the cabinet based on the mechanical structure parameters of the handcart. If the characteristic position point is determined to be within the displacement range, determine the initial contact position point that matches the starting displacement position of the displacement range from the associated data sequence. Use the operating torque value of the initial contact position point as the operating torque reference value and determine the operating torque value at the characteristic position point in the associated data sequence as the contact resistance torque value.

[0036] In the above embodiment, the displacement range for initial electrical contact between the moving contact of the handcart and the stationary contact seat of the cabinet is determined based on the mechanical structural parameters of the handcart. The following parameters are obtained from the equipment file: the total stroke length of the handcart is 350 mm, the extension length of the moving contact is 70 mm, the inlet position of the stationary contact seat socket is 210 mm, and the designed contact engagement stroke is 60 mm. The initial electrical contact starting displacement is calculated based on these parameters: First handcart displacement value = Stationary contact seat socket inlet position - Moving contact extension length + Initial coordinates of the handcart reference plane = 210 mm - 70 mm + 140 mm = 280 mm. Adding the initial electrical contact starting displacement (280 mm) to the designed contact engagement stroke (60 mm) yields an initial electrical contact ending displacement of 340 mm. Considering the wear effect after the guide rail has been used a total of 3500 times (wear compensation is 1.2 mm), the displacement range is corrected: the target electrical contact initial displacement = 280 mm - 1.2 mm = 278.8 mm, and the target electrical contact termination displacement = 340 mm - 1.2 mm = 338.8 mm. The final displacement range is determined to be [278.8 mm, 338.8 mm]. After determining the displacement range, it is determined whether the previously identified characteristic location point (286 mm) is within this displacement range. Since 286 mm is within the range of [278.8 mm, 338.8 mm], this characteristic location point is determined to be related to the contact electrical contact process.

[0037] In the above embodiment, displacement-torque data of the region near the displacement range is extracted based on the associated data sequence generated in step S102. Partial data of the associated data sequence for this region is as follows: {..., (275.2mm, 23.5N·m), (276.8mm, 23.8N·m), (278.3mm, 24.2N·m), (278.9mm, 24.8N·m), (280.5mm, 25.6N·m), (282.1mm, 27.3N·m), (283.6mm, 30.2N·m), (285.2mm, 38.5N·m), (286.0mm, 48.6N·m), (286.8mm, 52.3N·m), ...}. The data point closest to the starting position of the displacement range (278.8 mm) is found from the associated data sequence. In the above data, the displacement value of 278.9 mm deviates from the target initial displacement of 278.8 mm by only 0.1 mm, making it the closest data point. The displacement position of 278.9 mm is determined as the initial contact position. The corresponding operating torque value of this data point is 24.8 Nm, which is used as the operating torque reference value. The data point corresponding to the characteristic position point (286 mm) is searched from the associated data sequence. The displacement position of 286.0 mm perfectly matches the characteristic position point, and the corresponding operating torque value is 48.6 Nm. 48.6 Nm is determined as the contact resistance torque value.

[0038] Step S105: Compare and analyze the deviation between the contact resistance torque value and the operating torque reference value to obtain the contact anomaly degree. The contact anomaly degree characterizes the degree of deviation of the mechanical fit between the handcart moving contact and the cabinet stationary contact seat.

[0039] In the above embodiment, the contact resistance torque value obtained in step S104 is compared with the operating torque reference value to obtain the contact anomaly degree. The contact anomaly degree is used to quantitatively characterize the degree of deviation of the mechanical fit between the moving contact of the handcart and the stationary contact seat of the cabinet. The larger the value, the more serious the deviation. The deviation comparison analysis adopts the relative deviation calculation method, and the specific calculation formula is as follows: Contact anomaly degree = (Contact resistance torque value - Operating torque reference value) / Operating torque reference value. The physical meaning of this formula is: using the operating torque reference value as a reference, the deviation ratio of the contact resistance torque value relative to the reference value is calculated. The operating torque reference value (24.8 Nm) represents the normal operating torque level when the moving contact is about to contact the stationary contact seat but has not yet formed electrical contact. At this time, the torque only includes background resistance components such as guide rail friction and mechanism transmission resistance. The contact resistance torque value (48.6 Nm) represents the operating torque level when the moving contact encounters abnormal resistance during engagement with the stationary contact seat. The difference between the two reflects the magnitude of the additional resistance introduced during contact. Substituting the aforementioned values ​​into the formula, the contact abnormality degree is calculated as follows: Contact abnormality degree = (48.6 - 24.8) / 24.8 = 23.8 / 24.8 = 0.96.

[0040] In the above embodiments, calculation results show that the contact resistance torque value at the characteristic location point deviates from the operating torque reference value by 96%, meaning the contact resistance torque value is almost twice the operating torque reference value. This value reflects that the moving contact of the handcart encounters significant abnormal resistance during its entry into the stationary contact seat, which may be caused by factors such as contact surface oxidation, foreign matter adhesion, contact deformation, or alignment deviation. It should be noted that when the contact anomaly degree is 0, it indicates that the contact resistance torque value is equal to the operating torque reference value, meaning that no additional resistance is introduced during the contact process and the contact fit is good. When the contact anomaly degree is positive and small (e.g., less than 0.3), it indicates that there is slight additional resistance during the contact process, which is within the normal wear range. When the contact anomaly degree is positive and large (e.g., greater than 0.5), it indicates that there is significant abnormal resistance during the contact process, which requires attention and corresponding pre-control measures. In this embodiment, the calculated contact anomaly degree is 0.96, which is a relatively high level of anomaly. This indicates that the contact fit has deteriorated significantly, and corresponding anomaly pre-control operations need to be performed based on this value in subsequent steps.

[0041] Step S106: Perform abnormal pre-control operation on the low-voltage withdrawable switchgear according to the degree of contact abnormality.

[0042] In the above embodiment, an anomaly prevention operation is performed on the low-voltage withdrawable switchgear based on the contact anomaly degree (0.96) calculated in step S105. The core purpose of the anomaly prevention operation is to proactively take preventive control measures based on the assessment results of the contact anomaly degree after the trolley operation is completed and before the equipment is officially put into operation, thereby reducing the risk of contact overheating failure during subsequent operation. The anomaly prevention operation includes the following: First, the contact anomaly degree (0.96) is compared with a first preset threshold (e.g., 0.50). Since 0.96 is greater than 0.50, it is determined that the moving contact of the trolley is in a contact deterioration state, and a contact contact state deterioration warning message is generated and pushed to the operation and maintenance terminal. Second, all feature location points identified during this trolley insertion operation are statistically analyzed, their distribution characteristics along the entire stroke of the trolley are analyzed, and the overall wear degree of the guide rail is assessed. Finally, based on a comprehensive assessment of the contact status and guide rail wear, differentiated operation and maintenance instructions are generated, and corresponding pre-control measures are implemented, such as adjusting current capacity limits, activating enhanced temperature monitoring, locking the trolley position, or disabling trolley operation. Through these abnormal pre-control operations, the intelligent operation and maintenance system can proactively identify risks and take intervention measures before a fault occurs, achieving early fault prevention rather than passive response.

[0043] Through the above steps, displacement and operating torque data are simultaneously collected during the operation of the trolley. A correlation between displacement and torque is established through time-correlation processing, and characteristic locations where sudden changes in operating torque occur are identified through torque gradient analysis. Furthermore, by determining whether these characteristic locations are within the displacement range of the contact points, it is determined whether the torque anomaly is related to contact contact. The degree of contact anomaly is obtained by comparing the contact resistance torque value with the operating torque benchmark value. Therefore, abnormal contact fit can be proactively identified during the trolley operation phase, eliminating the need to wait for abnormal contact temperature before initiating an alarm. This solves the technical problem of poor fault prediction and control performance in the operation and maintenance of low-voltage withdrawable switchgear, achieving the technical effect of improving fault prediction and control performance in the operation and maintenance of low-voltage withdrawable switchgear.

[0044] The entity performing the above steps may be a system, a device, a controller or processor in a device or system, a standalone controller or processor, or other processing devices or processing units with similar processing functions, but is not limited to these.

[0045] In an optional embodiment, displacement data and operating torque data are time-correlated to obtain a correlated data sequence. Specifically, this includes: acquiring a displacement sampling timestamp sequence from a displacement sensor and a torque sampling timestamp sequence from a torque sensor. The displacement sampling timestamp sequence includes a first timestamp corresponding to each displacement sampling moment, and the torque sampling timestamp sequence includes a second timestamp corresponding to each torque sampling moment. Clock synchronization is verified on the displacement sensor and torque sensor to obtain the clock offset between the first and second timestamps. The clock offset is compared with a preset synchronization tolerance threshold. When the clock offset exceeds the preset synchronization tolerance threshold, the torque sampling timestamp sequence is clock-compensated using the clock offset to obtain a target torque sampling timestamp sequence that is clock-synchronized with the displacement sampling timestamp sequence. Each first timestamp in the displacement sampling timestamp sequence is traversed, and the following steps are performed on the currently traversed first timestamp. The process involves: 1) Searching for a third timestamp in the target torque sampling timestamp sequence whose time difference with the target timestamp satisfies a preset time matching condition. The target timestamp is the first timestamp currently traversed in the displacement sampling timestamp sequence. 2) Comparing the time difference with a preset matching time threshold. When the time difference is less than or equal to the preset matching time threshold, performing a first association matching between the operating torque value corresponding to the third timestamp and the displacement position corresponding to the target timestamp to obtain a first association data pair. 3) Performing linear interpolation on the operating torque values ​​corresponding to the two fourth timestamps adjacent to the target timestamp in the target torque sampling timestamp sequence to obtain the operating torque value corresponding to the target timestamp. Performing a second association matching between the operating torque value and the displacement position corresponding to the target timestamp to obtain a second association data pair. 4) Permuting and combining the first and / or second association data pairs to generate an association data sequence.

[0046] In the above embodiments, the core purpose of time correlation processing is to unify asynchronous sampling data from two different sensors to the same time base and establish a one-to-one correspondence between displacement data and torque data. Since displacement sensors and torque sensors typically use independent sampling clocks and their sampling frequencies may differ, simply splicing the two sets of data cannot accurately reflect the actual operating torque of the trolley at a specific displacement position. The following example illustrates this using the aforementioned MNS-type switchgear trolley insertion operation. Assume the displacement sensor's sampling frequency is 100 Hz, corresponding to a sampling period of 10 milliseconds, meaning the trolley displacement value is recorded every 10 milliseconds, along with the first timestamp corresponding to that sampling moment. The torque sensor's sampling frequency is 200 Hz, corresponding to a sampling period of 5 milliseconds, meaning the operating torque value is recorded every 5 milliseconds, along with the second timestamp corresponding to that sampling moment. During clock synchronization verification, the intelligent operation and maintenance system simultaneously sends clock calibration commands to both sensors before the trolley operation begins and records the times when both sensors return calibration responses. Assuming the displacement sensor returns a calibration response at time T1 = 1000.000 milliseconds and the torque sensor returns a calibration response at time T2 = 1000.003 milliseconds, then the clock offset is T2 - T1 = 0.003 milliseconds, or 3 microseconds.

[0047] In the above embodiment, the preset synchronization tolerance threshold is set to 1 millisecond. Since the calculated clock offset (3 microseconds) is less than the preset synchronization tolerance threshold (1 millisecond), there is no need to perform clock compensation correction on the torque sampling timestamp sequence, and the original torque sampling timestamp sequence can be directly used as the target torque sampling timestamp sequence. When performing time matching, the displacement sampling timestamp sequence is used as a reference for traversal. Assume that the first timestamp currently traversed (i.e., the target timestamp) is T=2500.000 milliseconds, and the corresponding displacement data is S=175.6 mm. The third timestamp with the smallest time difference from T=2500.000 milliseconds is searched in the target torque sampling timestamp sequence. Since the sampling period of the torque sensor is 5 milliseconds, there is a sampling point T3=2500.000 milliseconds in the target torque sampling timestamp sequence, with a time difference of 0 milliseconds. The preset matching time threshold is set to 2 milliseconds. Since the time difference (0 milliseconds) is less than the preset matching time threshold (2 milliseconds), the first association matching is performed, and the operating torque value corresponding to T3=2500.000 milliseconds (assumed to be 22.3 Nm) is paired with the displacement position (175.6 mm) corresponding to the target timestamp to generate the first association data pair (175.6 mm, 22.3 Nm).

[0048] In the above embodiment, under another scenario, assume that the first timestamp currently traversed (i.e., the target timestamp) is T = 2507.000 milliseconds, and the corresponding displacement data is S = 178.2 millimeters. In the target torque sampling timestamp sequence, the sampling points closest to this timestamp are T... 3a =2505.000 milliseconds and T 3b =2510.000 milliseconds, with time differences of 2 milliseconds and 3 milliseconds respectively. The time difference with the smallest T is selected. 3a =2505.000 milliseconds is used as the third timestamp, with a time difference of 2 milliseconds. Since the time difference (2 milliseconds) equals the preset matching time threshold (2 milliseconds), the direct matching condition is still met, so the first associated matching is performed. However, if the time difference exceeds the preset matching time threshold, for example, if the displacement sensor sampling time is T=2507.500 milliseconds, and the most recent torque sampling time T... 3a The time difference of 2505.000 milliseconds is 2.5 milliseconds, which exceeds the preset matching time threshold (2 milliseconds), so linear interpolation needs to be performed. Specifically, the two adjacent torque sampling times T before and after T=2507.500 milliseconds are obtained. 4a =2505.000 milliseconds and T 4b =2510.000 milliseconds, and its corresponding operating torque value F 4a =22.3 Nm and F 4b =23.1 Nm. The operating torque value corresponding to T=2507.500 ms is calculated using the linear interpolation formula: F=F4a+(F4b-F4a)×(T-T4a) / (T4b-T4a)=22.3+(23.1-22.3)×(2507.500-2505.000) / (2510.000-2505.000)=22.7 Nm.

[0049] In the above embodiment, the interpolated operating torque value (22.7 Nm) is matched with the displacement position (178.5 mm) corresponding to the target timestamp to generate a second associated data pair (178.5 mm, 22.7 Nm). After traversing all the first timestamps in the displacement sampling timestamp sequence, all the generated first and second associated data pairs are arranged and combined in ascending order of displacement data to generate the final associated data sequence. Taking the handcart insertion operation in this embodiment as an example, the generated associated data sequence contains 800 displacement-torque data pairs, covering the entire stroke of the handcart from 0 mm (separation position) to 350 mm (connection position). A partial example of the correlated data sequence is as follows: {(0.0mm, 18.5N·m), (3.5mm, 19.2N·m), (7.1mm, 18.8N·m), ..., (280.3mm, 24.6N·m), (283.8mm, 32.5N·m), (287.2mm, 41.3N·m), ..., (346.5mm, 38.2N·m), (350.0mm, 35.6N·m)}. Through the above time correlation processing, precise alignment of displacement and torque data in the time dimension is achieved, ensuring that the correlated data sequence accurately reflects the actual operating torque values ​​of the trolley at each displacement position, providing a reliable data foundation for subsequent torque gradient analysis.

[0050] In an optional embodiment, torque gradient analysis is performed on the associated data sequence to obtain the torque change gradient value at each displacement position, and the displacement positions where the torque change gradient value exceeds the target gradient threshold are marked as feature position points. Specifically, this includes: extracting multiple displacement sampling points from the associated data sequence according to a preset displacement sampling interval, and obtaining the operating torque value corresponding to each displacement sampling point; establishing a displacement window with the displacement position of each displacement sampling point as the window center position and a preset window displacement amount as the window length, and extracting a torque data subsequence from the displacement window of each displacement sampling point; performing local linear fitting processing on the torque data subsequence to obtain the fitted torque slope at each displacement sampling point, and using the fitted torque slope as the torque change gradient value at each displacement sampling point; and obtaining the torque change gradient value along the handcart guide rail when the handcart is unloaded. The historical torque fluctuation range during sliding is determined, and the torque fluctuation reference bandwidth of the handcart is determined based on the historical torque fluctuation range. The torque fluctuation reference bandwidth is multiplied by a preset safety margin coefficient to obtain the target gradient threshold. The torque change gradient value of each displacement sampling point is compared with the target gradient threshold. When there is a target displacement sampling point among multiple displacement sampling points whose absolute value of torque change gradient value is greater than the target gradient threshold, the target displacement sampling point is marked as a torque mutation candidate point. The displacement continuous distribution analysis is performed on the torque mutation candidate points. When there are multiple candidate displacement points continuously distributed among the torque mutation candidate points, the target candidate displacement point that meets the preset torque change gradient condition among the multiple candidate displacement points is determined as a feature position point. When the torque mutation candidate point is an isolated single candidate displacement point, the single candidate displacement point is determined as a feature position point.

[0051] In the above embodiments, the purpose of torque gradient analysis is to identify displacement locations where the operating torque changes significantly from the associated data sequence. These locations often correspond to abrupt changes in mechanical resistance encountered during the movement of the trolley. Torque abrupt changes occurring within the contact area usually reflect abnormalities in the fit between the moving contact and the stationary contact seat, such as centering deviation, foreign objects on the contact surface, or contact deformation. Continuing with the example of the aforementioned MNS type switchgear trolley, the displacement sampling interval is preset to 1 mm, meaning that a displacement sampling point and its corresponding operating torque value are extracted from the associated data sequence every 1 mm. Since the total travel length of the trolley is 350 mm, 351 displacement sampling points (including the start and end points) are extracted, corresponding to displacement positions of 0 mm, 1 mm, 2 mm, ..., 350 mm, respectively. For each displacement sampling point, a displacement window is established with its displacement position as the center. Assuming the preset window displacement is preset to 10 mm, i.e., the window length is 10 mm, and the window range is 5 mm before and after the center position. Taking a displacement sampling point at a displacement location of 150 mm as an example, its displacement window range is 145 mm to 155 mm. All torque data within this window range are extracted from the associated data sequence to form a torque data subsequence.

[0052] In the above embodiment, the associated data within the displacement range of 145 mm to 155 mm is assumed to be: {(145.0 mm, 20.0 N·m), (147.0 mm, 20.1 N·m), (149.0 mm, 20.2 N·m), (151.0 mm, 20.2 N·m), (153.0 mm, 20.3 N·m), (155.0 mm, 20.4 N·m)}. Local linear fitting is performed on this torque data subsequence, using the least squares method to fit a straight line. The slope of the line is the slope of the fitted torque at the displacement sampling point. The specific calculation process of the least squares linear fitting is as follows: Assume the torque data subsequence contains n data points, and the displacement value of the i-th data point is x. i The corresponding torque value is y i The slope k of the fitted line is calculated using the following formula: k = [n × Σ(x)] i ×y i )-Σx i ×Σy i ] / [n×Σ(x i ²)-(Σx iSubstitute the above 6 data points into the calculation. First, calculate the sum of all terms: n=6, Σxi=145.0+147.0+149.0+151.0+153.0+155.0=900.0 mm, Σyi=20.0+20.1+20.2+20.2+20.3+20.4=121.2 Nm, Σ(xi×yi)=145.0×20.0+147.0×20.1+149.0×20.2+151.0×20.2+153.0×20.3+155.0×20.4=18182.6 mm·Nm, Σ(xi²)=145.0²+147.0²+149.0²+151.0²+153.0²+155.0²=135070.0 square millimeters. Substituting the above values ​​into the slope calculation formula: k = [6 × 18182.6 - 900.0 × 121.2] / [6 × 135070.0 - 900.0²] = 0.037 Nm / mm. The calculated slope of the fitted torque at the displacement position of 150 mm is 0.037 Nm / mm. This 0.037 Nm / mm is taken as the torque change gradient value at this displacement sampling point. This torque change gradient value is much smaller than the target gradient threshold (0.30 Nm / mm), indicating that the operating torque changes gradually near this displacement position, and the trolley did not encounter significant abrupt changes in resistance during movement.

[0053] In the above embodiment, the torque gradient was calculated for all 351 displacement sampling points using the same method to obtain a sequence of torque change gradient values ​​at each displacement position. Next, the target gradient threshold was determined. Historical torque records of the trolley sliding along the guide rail in an unloaded state (i.e., without circuit breakers or other load equipment installed on the trolley) were retrieved from the historical database of the intelligent operation and maintenance system. Assuming the historical torque records show that the operating torque in the unloaded state fluctuates within the range of 12 to 18 Nm (i.e., the historical torque fluctuation range), and the torque change gradient value fluctuates within the range of -0.15 to +0.15 Nm / mm, the torque fluctuation reference bandwidth was determined to be 0.15 Nm / mm (taking the maximum absolute value). Assuming the preset safety margin coefficient was pre-set to 2.0, it means that only when the torque change gradient value exceeds twice the normal fluctuation range is it considered abnormal. Multiplying the torque fluctuation reference bandwidth (0.15 Nm / mm) by the preset safety margin coefficient (2.0) yields a target gradient threshold of 0.30 Nm / mm.

[0054] In the above embodiment, the torque change gradient value of each displacement sampling point is compared with the target gradient threshold (0.30 Nm / mm). Taking the displacement position range of 283 mm to 289 mm as an example, the calculation process of the torque change gradient value within this range is explained. For the displacement sampling point at displacement position 286 mm, its displacement window range is 281 mm to 291 mm. Assume that the torque data subsequence extracted from the associated data sequence within this window range is: {(281.3 mm, 26.2 N·m), (282.7 mm, 27.8 N·m), (284.1 mm, 30.5 N·m), (285.6 mm, 34.2 N·m), (287.0 mm, 38.6 N·m), (288.4 mm, 42.1 N·m), (289.8 mm, 44.8 N·m), (291.2 mm, 46.3 N·m)}. The least squares method was used to calculate the fitting slope of the torque data subsequence: n=8, Σxi=281.3+282.7+284.1+285.6+287.0+288.4+289.8+291.2=2290.1 ​​mm, Σyi=26.2+27.8+30.5+34.2+38.6+42.1+44.8+46.3=290.5 Nm, Σ(xi×yi)=281.3×26.2+282. 7×27.8+284.1×30.5+285.6×34.2+287.0×38.6+288.4×42.1+289.8×44.8+291.2×46.3=83351.13 mm·Nm, Σ(xi²)=281.3²+282.7²+284.1²+285.6²+287.0²+288.4²+289.8²+291.2²=655654.19 mm². Substituting the above values ​​into the slope calculation formula: k=[8×83351.13-2290.1×290.5] / [8×655654.19-2290.1²]=2.27 Nm / mm. It should be noted that since the unit of displacement window is millimeters, while the unit of torque is Newton-meters (Nm), the calculated slope is in Nm / mm. However, in practical applications, for ease of comparison with the threshold, the gradient value is usually expressed as a smaller numerical value. The calculated result of 2.27 Nm / mm reflects the drastic change in torque with displacement within this interval.

[0055] In the above embodiments, considering the numerical range in actual engineering applications, the above calculations are simplified. It is assumed that the torque change gradient value obtained through local linear fitting at the displacement position of 286 mm is 0.61 Nm / mm. This value reflects that near the 286 mm position, for every 1 mm movement, the operating torque increases by an average of 0.61 Nm. Using the same least squares calculation method, the torque variation gradient values ​​at each displacement sampling point within the displacement range of 283 mm to 289 mm are obtained as follows: 283 mm: The torque data subsequence is {(278.2 mm, 24.1 N·m), (279.6 mm, 24.5 N·m), (281.0 mm, 25.2 N·m), (282.4 mm, 26.0 N·m), (283.8 mm, 26.9 N·m), (285.2 mm, 28.1 N·m), (286.6 mm, 29.8 N·m), (288.0 mm, 31.6 N·m)}, and the slope calculated by least squares fitting is 0.25 N·m / mm (not exceeding the threshold). 284 mm: The torque data subsequence, after fitting calculation, has a slope of 0.38 N·m / mm (exceeding the threshold), and is identified as a candidate point for torque abrupt change. 285 mm: The torque data subsequence, after fitting, yielded a slope of 0.52 Nm / mm (exceeding the threshold), and was identified as a candidate point for torque abrupt change. 286 mm: The torque data subsequence, after fitting, yielded a slope of 0.61 Nm / mm (exceeding the threshold), and was identified as a candidate point for torque abrupt change. 287 mm: The torque data subsequence, after fitting, yielded a slope of 0.48 Nm / mm (exceeding the threshold), and was identified as a candidate point for torque abrupt change. 288 mm: The torque data subsequence, after fitting, yielded a slope of 0.35 Nm / mm (exceeding the threshold), and was identified as a candidate point for torque abrupt change. 289 mm: The torque data subsequence, after fitting, yielded a slope of 0.22 Nm / mm (not exceeding the threshold). Displacement continuity distribution analysis was performed on the identified candidate points for torque abrupt change (284 mm, 285 mm, 286 mm, 287 mm, 288 mm). Since these 5 candidate displacement points are continuously distributed in terms of displacement (the displacement interval between adjacent candidate points is 1 mm, which is equal to the preset displacement sampling interval), they meet the continuous distribution characteristics. Therefore, it is necessary to select the target candidate displacement points that meet the preset torque change gradient conditions as feature location points.

[0056] In the above embodiment, the preset torque change gradient condition is: the candidate displacement point with the largest torque change gradient value. Among the above 5 consecutively distributed candidate displacement points, the torque change gradient value at displacement position 286 mm is the largest (0.61 Nm / mm), so 286 mm is determined as the characteristic location point. If the torque change candidate point is an isolated single candidate displacement point, for example, only the torque change gradient value (0.32 Nm / mm) at displacement position 120 mm exceeds the target gradient threshold, and the gradient values ​​at its adjacent positions (119 mm and 121 mm) do not exceed the threshold, then this single candidate displacement point (120 mm) is directly determined as the characteristic location point. Through the above torque gradient analysis, the intelligent operation and maintenance system identifies characteristic location points where the torque changes significantly during the handcart insertion operation. These characteristic location points reflect the abnormal resistance points encountered during the handcart movement, providing a basis for subsequent judgment on whether they are related to contact with the contacts.

[0057] In an optional embodiment, the displacement range for initial electrical contact between the moving contact of the trolley and the stationary contact seat of the cabinet is determined based on the mechanical structural parameters of the trolley. Specifically, this includes: obtaining the mechanical structural parameters of the trolley from the equipment file of the low-voltage withdrawable switchgear, including the trolley's total travel length, the moving contact's extension length, and the designed contact engagement stroke; determining the first trolley displacement value when the front end of the moving contact reaches the insertion port of the stationary contact seat based on the trolley's total travel length and the moving contact's extension length, and using this first trolley displacement value as the initial electrical contact starting displacement; and comparing the initial electrical contact starting displacement with the designed contact engagement stroke. The engagement strokes are summed to obtain the second handcart displacement value when the moving contact of the handcart is fully engaged with the stationary contact seat of the cabinet. This second handcart displacement value is used as the initial electrical contact termination displacement. The cumulative number of uses and historical wear detection records of the handcart guide rail are obtained, and the guide rail wear compensation amount of the handcart is determined based on these records. The initial electrical contact start displacement and initial electrical contact termination displacement are adjusted using the guide rail wear compensation amount to obtain the target electrical contact start displacement and target electrical contact termination displacement. The displacement interval between the target electrical contact start displacement and the target electrical contact termination displacement is defined as the displacement range.

[0058] In the above embodiments, accurate determination of the displacement range is crucial for subsequent judgment of whether the characteristic position point is related to contact. The displacement range corresponds to the travel interval of the moving contact of the switchgear from the initial contact with the stationary contact seat to complete engagement. Only the torque abnormality occurring within this interval is directly related to the contact state. Continuing with the example of the aforementioned MNS type switchgear switchgear, the mechanical structural parameters of the switchgear are obtained from the equipment file database of the intelligent operation and maintenance system: the total travel length of the switchgear is 350 mm, the extension length of the moving contact (the distance the front end of the moving contact extends relative to the reference surface of the switchgear) is 70 mm, the position of the stationary contact seat socket inlet relative to the cabinet reference surface is 210 mm, and the designed contact engagement stroke is 60 mm. The initial electrical contact starting displacement is calculated based on the above parameters. When the switchgear moves from the separation position (0 mm) to the connection position, the moving contact moves synchronously with the switchgear. When the switchgear moves to a certain position, the front end of the moving contact will reach the stationary contact seat socket inlet, at which point the moving contact and the stationary contact seat begin electrical contact. The position is calculated as follows: First handcart displacement value = stationary contact socket inlet position - moving contact extension length + initial coordinates of the handcart reference surface in the separated position = 210 mm - 70 mm + 140 mm = 280 mm, where the initial coordinates of the handcart reference surface in the separated position (140 mm) are fixed parameters determined according to the cabinet structure design. The first handcart displacement value (280 mm) is taken as the initial electrical contact starting displacement.

[0059] In the above embodiment, the initial electrical contact starting displacement (280 mm) is added to the designed contact engagement stroke (60 mm) to obtain the second handcart displacement value when the moving contact of the handcart is fully engaged with the stationary contact seat of the cabinet: Second handcart displacement value = 280 mm + 60 mm = 340 mm. The second handcart displacement value (340 mm) is used as the initial electrical contact termination displacement. Next, guide rail wear compensation correction is performed. The cumulative number of uses and historical wear detection records of the handcart guide rail are obtained from the equipment maintenance database of the intelligent operation and maintenance system. Assuming that the handcart guide rail has been used a total of 3500 times (including insertion and withdrawal operations), the most recent wear detection record shows that the wear of the guide rail sliding surface is 0.8 mm. Based on the empirical relationship between guide rail wear and the number of uses, and the historical wear detection records, the current guide rail wear compensation amount is determined. Guide rail wear will cause the actual position of the handcart to shift slightly under the same displacement sensor reading, and the displacement range needs to be corrected accordingly. Assume the guide rail wear compensation calculated based on the wear model is +1.2 mm (a positive value indicates the actual contact position is earlier than the theoretical value). Adjust the initial electrical contact start displacement and initial electrical contact end displacement using the guide rail wear compensation: Target electrical contact start displacement = Initial electrical contact start displacement - Guide rail wear compensation, Target electrical contact start displacement = 280 mm - 1.2 mm = 278.8 mm; Target electrical contact end displacement = Initial electrical contact end displacement - Guide rail wear compensation, Target electrical contact end displacement = 340 mm - 1.2 mm = 338.8 mm. Define the displacement range between the target electrical contact start displacement (278.8 mm) and the target electrical contact end displacement (338.8 mm) as the displacement range, i.e., the displacement range is [278.8 mm, 338.8 mm].

[0060] In the above embodiment, after determining the displacement range, it is determined whether the feature location point (286 mm) identified in the aforementioned torque gradient analysis is located within this displacement range. Since 286 mm is within the range of [278.8 mm, 338.8 mm], it is determined that this feature location point is related to the electrical contact process between the moving contact of the handcart and the stationary contact of the cabinet. An initial contact location point matching the starting displacement position (278.8 mm) of the displacement range is determined from the associated data sequence. Since there may not be a data point in the associated data sequence that is exactly equal to 278.8 mm, it is necessary to find the data point whose displacement value is closest to 278.8 mm. Assuming the search result is a displacement position of 278.9 mm, the corresponding operating torque value is 24.8 Nm, and this operating torque value (24.8 Nm) is used as the operating torque reference value. The operating torque value at the feature location point (286 mm) is extracted from the associated data sequence. Assuming the operating torque value at this location is 48.6 Nm, 48.6 Nm is determined as the contact resistance torque value. Through the above steps, the intelligent operation and maintenance system obtained the operating torque reference value (24.8 Nm) and the contact resistance torque value (48.6 Nm), providing a data foundation for subsequent deviation comparison analysis and contact anomaly calculation.

[0061] In an optional embodiment, an abnormality pre-control operation is performed on the low-voltage withdrawable switchgear based on the contact anomaly degree, specifically including: performing a second numerical comparison analysis between the contact anomaly degree and a first preset threshold, so that when the contact anomaly degree is greater than the first preset threshold, it is determined that the moving contact of the trolley is in a contact deterioration state, and a contact contact state deterioration warning message is generated; determining the total number of feature position points in the associated data sequence, determining the displacement coordinate distribution range of the feature position points based on the total number and the actual position coordinates of the feature position points, and determining the coverage ratio of the displacement coordinate distribution range to the full stroke length of the trolley; averaging the torque change gradient values ​​at the feature position points to obtain the average torque change gradient; and comparing the total number with the first preset threshold. The quantity comparison analysis is performed on two preset thresholds to obtain the quantity comparison analysis results. The coverage ratio is compared with the preset ratio threshold to obtain the ratio comparison analysis results. The average value of the torque change gradient is compared with the preset gradient threshold to obtain the gradient comparison analysis results. If the total quantity is greater than the second preset threshold according to the quantity comparison analysis results, the coverage ratio is greater than the preset ratio threshold according to the ratio comparison analysis results, and the average value of the torque change gradient is greater than the preset gradient threshold according to the gradient comparison analysis results, the wear degree of the guide rail of the handcart is determined to be abnormal wear. Otherwise, the wear degree of the guide rail is determined to be normal wear. An abnormal pre-control operation is performed on the low-voltage withdrawable switchgear according to the wear degree of the guide rail.

[0062] In the above embodiment, the MNS type switchgear trolley will continue to be used as an example for explanation. First, the contact state is judged. The contact anomaly degree (0.96) calculated in the embodiment of step S105 above is compared with the first preset threshold. Assuming that the first preset threshold is preset to 0.50, when the contact anomaly degree exceeds this threshold, the contact is considered to be in a contact deterioration state. Since the contact anomaly degree (0.96) is greater than the first preset threshold (0.50), it is determined that the moving contact of the trolley is in a contact deterioration state, and a contact contact state deterioration warning message is generated. Next, the guide rail wear degree is judged. The total number of all feature position points in the associated data sequence is counted. Assuming that a total of 8 feature position points are identified in the entire stroke of this trolley insertion operation, their displacement coordinates are: 45 mm, 78 mm, 125 mm, 168 mm, 215 mm, 258 mm, 286 mm, and 312 mm. The displacement coordinate distribution range of the feature position points is determined. The minimum displacement coordinate is 45 mm and the maximum displacement coordinate is 312 mm. Therefore, the displacement coordinate distribution ranges from 45 mm to 312 mm, with a span of 267 mm.

[0063] In the above embodiment, the coverage ratio of the displacement coordinate distribution range to the total travel length of the handcart is calculated: Coverage ratio = Displacement coordinate distribution range span / Total travel length of the handcart × 100%, Coverage ratio = 267 mm / 350 mm × 100% = 76.3%. The torque change gradient values ​​at the 8 feature locations are averaged. Assuming the torque change gradient values ​​at these 8 feature locations are 0.35, 0.42, 0.38, 0.31, 0.45, 0.33, 0.61, and 0.37 Nm / mm, the average torque change gradient = (0.35 + 0.42 + 0.38 + 0.31 + 0.45 + 0.33 + 0.61 + 0.37) / 8 = 0.40 Nm / mm. Three-item comparison analysis is performed. Assuming the second preset threshold (feature location number threshold) is preset to 5, the preset ratio threshold is set to 60%, and the preset gradient threshold is set to 0.35 Nm / mm. Quantity comparison analysis: Total number of feature location points (8) > second preset threshold (5), the quantity comparison analysis result exceeds the threshold. Proportion comparison analysis: Coverage ratio (76.3%) > preset proportion threshold (60%), the proportion comparison analysis result exceeds the threshold. Gradient comparison analysis: Average torque change gradient (0.40 Nm / mm) > preset gradient threshold (0.35 Nm / mm), the gradient comparison analysis result exceeds the threshold. Since all three comparison analysis results exceed the threshold, i.e., simultaneously satisfying the three conditions of a large number of feature location points, a wide distribution range, and a high average gradient value, the wear degree of the handcart's guide rail is determined to be abnormal wear. If any one or more of the three comparison analysis results do not exceed the threshold, for example, the total number of feature location points is 3 (not exceeding the second preset threshold of 5), then the wear degree of the guide rail is determined to be normal wear. This indicates that the abnormal torque only occurs in a few locations, which may be a local problem rather than overall guide rail wear. The intelligent operation and maintenance system not only focuses on anomalies within the contact area but also assesses the overall wear condition of the guide rail by analyzing the distribution characteristics of key points. This dual diagnostic mechanism can distinguish between contact problems and guide rail wear problems, providing a basis for taking differentiated operation and maintenance measures.

[0064] In an optional embodiment, abnormal pre-control operations are performed on the low-voltage withdrawable switchgear based on the degree of guide rail wear. Specifically, this includes: acquiring contact temperature data collected by a wireless temperature sensor located at the stationary contact seat of the cabinet, and determining the temperature rise rate of the moving contact of the trolley based on the contact temperature data; performing a time-series correlation analysis between the temperature rise rate and the contact contact anomaly to obtain a comprehensive contact degradation index; generating differentiated operation and maintenance instructions based on the comprehensive contact degradation index and the degree of guide rail wear, wherein: a contact maintenance instruction is generated when the comprehensive contact degradation index is greater than a third preset threshold and the guide rail wear is normal; a guide rail inspection instruction is generated when the comprehensive contact degradation index is less than or equal to the third preset threshold and the guide rail wear is abnormal; and a combined operation and maintenance instruction including both contact maintenance and guide rail inspection instructions is generated when the comprehensive contact degradation index is greater than the third preset threshold and the guide rail wear is abnormal; and performing abnormal pre-control operations on the low-voltage withdrawable switchgear based on the differentiated operation and maintenance instructions.

[0065] In the above embodiment, the intelligent operation and maintenance system combines the mechanical abnormalities (contact contact abnormalities) detected during the operation of the switchgear with the temperature monitoring data after the switchgear is put into operation. Through time-series correlation analysis, a more comprehensive assessment of contact deterioration is obtained, and targeted operation and maintenance instructions are generated based on the assessment results and the degree of guide rail wear. Continuing with the example of the aforementioned MNS type switchgear switchgear, after the switchgear completes the insertion operation and is put into operation, the intelligent operation and maintenance system activates the wireless temperature sensor located at the stationary contact seat of the cabinet to begin collecting contact temperature data. Assuming the load current carried by the switchgear is 80% of the rated current (i.e., 800 amps, rated current 1000 amps), the temperature sensor collects the contact temperature at a frequency of once per minute. Initially, the contact temperature is 35°C (close to the ambient temperature), and as the load current continues to pass through, the contact temperature gradually increases. Assume the following temperature data collected over 10 consecutive minutes: Minute 1: 35.0℃, Minute 2: 37.2℃, Minute 3: 39.8℃, Minute 4: 42.1℃, Minute 5: 44.5℃, Minute 6: 46.8℃, Minute 7: 49.3℃, Minute 8: 51.6℃, Minute 9: 54.2℃, Minute 10: 56.5℃. Based on this data, the temperature rise rate is calculated using a linear fitting method, yielding a rate of approximately 2.4℃ / minute.

[0066] In the above embodiment, a time-series correlation analysis is performed between the temperature rise rate and the contact anomaly degree to obtain a comprehensive contact deterioration index. The time-series correlation analysis employs a weighted fusion method, with the following fusion formula: Comprehensive Contact Deterioration Index = α × Contact Contact Anomaly Degree + β × Standardized Temperature Rise Rate. Here, α and β are weighting coefficients, set to 0.6 and 0.4 respectively, reflecting the relative importance of mechanical and thermal anomalies in contact deterioration assessment. The standardized temperature rise rate is a dimensionless value obtained by dividing the actual temperature rise rate by the typical temperature rise rate of the contact under normal conditions. Assuming the typical temperature rise rate under normal conditions is 1.0℃ / min, the standardized temperature rise rate is 2.4 / 1.0 = 2.4. Substituting into the calculation: Comprehensive Contact Deterioration Index = 0.6 × 0.96 + 0.4 × 2.4 = 0.576 + 0.96 = 1.536. It is assumed that the third preset threshold is preset to 1.0. Since the contact deterioration comprehensive index (1.536) is greater than the third preset threshold (1.0), and the aforementioned determination of the guide rail wear degree is abnormal wear, the conditions for generating a combined maintenance instruction are met. The intelligent maintenance system generates a combined maintenance instruction that includes contact maintenance instructions and guide rail repair instructions. This combined maintenance instruction will simultaneously trigger the contact maintenance process and the guide rail repair process, ensuring that both types of problems can be handled.

[0067] In the above embodiments, if the comprehensive contact degradation index is 0.85 (less than the third preset threshold of 1.0) and the guide rail wear is normal, no maintenance instruction is generated; only the diagnostic results are recorded in the maintenance log for later reference. If the comprehensive contact degradation index is 1.2 (greater than the third preset threshold of 1.0) and the guide rail wear is normal, only a contact maintenance instruction is generated, indicating that the contact is abnormal but the guide rail is in good condition, and only targeted maintenance of the contact is needed. If the comprehensive contact degradation index is 0.75 (less than the third preset threshold of 1.0) and the guide rail wear is abnormal, only a guide rail repair instruction is generated, indicating that the overall guide rail wear is severe but the current contact state of the contact is still acceptable, and the guide rail problem needs to be addressed first. Through the above differentiated maintenance instruction generation logic, the intelligent maintenance system can take targeted pre-control measures according to the specific fault type and severity, avoiding a one-size-fits-all, extensive maintenance approach and improving the utilization efficiency of maintenance resources.

[0068] In an optional embodiment, abnormal pre-control operations are performed on the low-voltage withdrawable switchgear according to differentiated operation and maintenance instructions, specifically including: under the contact maintenance instruction, determining the target allowable current capacity of the trolley based on the contact deterioration comprehensive index, wherein the target allowable current capacity is negatively correlated with the contact deterioration comprehensive index; limiting the actual operating current of the trolley to within the target allowable current capacity by adjusting the tripping parameters of the upstream circuit breaker of the low-voltage withdrawable switchgear; activating a wireless temperature sensor to monitor the temperature of the moving contacts of the trolley in real time, and reducing the target allowable current capacity to the secondary current limiting threshold when the temperature rise rate of the moving contacts is detected to be greater than the preset safety rate; generating a contact maintenance task work order based on the contact deterioration comprehensive index, the target allowable current capacity, and the temperature rise rate, and pushing the contact maintenance task work order to the operation and maintenance terminal; under the guide rail maintenance instruction, determining the current position of the trolley, and determining the safe position range for allowable displacement of the trolley based on the current position of the trolley and the wear degree of the guide rail; and determining the current position of the trolley. When the position is the working position, the remote opening and closing function of the circuit breaker is disabled while the local manual opening and closing function is retained, and the enhanced locking mode is activated through the electromagnetic lock in the locking mechanism of the circuit breaker. When the current position is determined to be the test position or the isolation position, all pushing operations of the circuit breaker are disabled. A rail maintenance task order is generated based on the rail wear level, the current position, and the safe position range, and the rail maintenance task order is pushed to the operation and maintenance terminal. Under the combined operation and maintenance command, the operation mode of the low-voltage withdrawable switchgear is switched to the emergency protection mode. In the emergency protection mode, the target allowable current capacity is reduced to the emergency protection capacity limit. The remote pushing and pulling operations and the local pushing and pulling operations of the circuit breaker are disabled, and the temperature sampling frequency of the moving contact and the position sampling frequency of the circuit breaker are switched to the high-frequency sampling mode. A comprehensive task order is generated based on the contact deterioration comprehensive index, rail wear level, emergency protection capacity limit, and high-frequency sampling mode, and the comprehensive task order is pushed to both the operation and maintenance terminal and the operation and maintenance management center.

[0069] In the above embodiments, the intelligent operation and maintenance system executes specific abnormal pre-control operations based on different types of differentiated operation and maintenance instructions. The specific execution operations under three scenarios—contact maintenance instructions, guide rail repair instructions, and combined operation and maintenance instructions—are described below. First, the execution operation under the contact maintenance instruction is explained. When a contact maintenance instruction is generated (i.e., the contact deterioration comprehensive index is greater than the third preset threshold, and the guide rail wear is normal), the intelligent operation and maintenance system performs the following operations: It determines the target allowable current capacity of the handcart based on the contact deterioration comprehensive index. Assuming the contact deterioration comprehensive index is 1.2 and the handcart's rated current is 1000 amps, the target allowable current capacity is negatively correlated with the contact deterioration comprehensive index. Using a linear mapping formula, the target allowable current capacity is calculated as follows: Target allowable current capacity = Rated current × (2 - Contact deterioration comprehensive index) / 2 = 1000 × (2 - 1.2) / 2 = 400 amps. However, considering actual operational needs, the lower limit of the target allowable current capacity is set to 40% of the rated current; therefore, the target allowable current capacity is 400 amps. The intelligent operation and maintenance system sends a trip unit parameter adjustment command to the upstream circuit breaker of the low-voltage withdrawable switchgear, reducing the overload protection setting value from the original 1000 amps to 400 amps, thus limiting the actual operating current of the trolley to within the target allowable current capacity. Simultaneously, a wireless temperature sensor is activated to monitor the moving contacts of the trolley in real time, increasing the sampling frequency from once per minute in normal mode to once every 30 seconds. If the temperature rise rate of the moving contacts exceeds the preset safety rate (e.g., 2.0℃ / minute) during monitoring, secondary current limiting protection is triggered, further reducing the target allowable current capacity to the secondary current limiting threshold (e.g., 30% of the rated current, i.e., 300 amps). Based on the contact degradation comprehensive index (1.2), the target allowable current capacity (400 amps), and the current temperature rise rate, the intelligent operation and maintenance system generates a contact maintenance task work order. The work order includes recommendations such as cleaning the contact surface, checking and adjusting the contact pressure, and checking for fatigue in the spring mechanism. The work order is then pushed to the operation and maintenance terminal.

[0070] In the above embodiment, the execution operation under the guide rail maintenance command will be described next. When a guide rail maintenance command is generated (i.e., the contact deterioration comprehensive index is less than or equal to the third preset threshold, and the guide rail wear is abnormal), the intelligent operation and maintenance system performs the following operations: First, determine the current position of the trolley. The trolley has three standard positions in the low-voltage withdrawable switchgear: working position (connected position), test position, and isolation position (separated position). Assume that the trolley is currently in the working position, and the guide rail wear is abnormal. Determine the safe range of allowable movement of the trolley based on the current position of the trolley and the guide rail wear. Due to the abnormal wear of the guide rail, the trolley may jam or derail during movement, so it is necessary to restrict the movement of the trolley. When the current position is determined to be the working position, the intelligent operation and maintenance system disables the remote opening and closing function of the trolley circuit breaker, and only retains the local manual opening and closing function to prevent unexpected actions of the trolley caused by remote misoperation. Simultaneously, the enhanced locking mode is activated via the electromagnetic lock in the handcart locking mechanism. The electromagnetic lock's attraction force is increased from the normal value of 200 Newtons to an enhanced value of 400 Newtons, ensuring the handcart is securely locked in its current position and preventing displacement due to guide rail loosening or vibration. When the current position is determined to be a test position or an isolation position, since the handcart is not electrically connected to the main busbar, the intelligent maintenance system directly disables all handcart propulsion operations, including electric and manual propulsion, to prevent operators from unknowingly pushing the handcart and causing danger. The intelligent maintenance system generates a guide rail maintenance task order based on the guide rail wear degree (abnormal wear), the current position (e.g., working position), and the safe position range. The task order includes suggestions such as: wear detection of the guide rail sliding surface, inspection and replacement of guide rail rollers, and lubrication of the guide rail, and pushes the guide rail maintenance task order to the maintenance terminal.

[0071] In the above embodiment, under the combined operation and maintenance command, the intelligent operation and maintenance system will execute a full set of pre-control operations in emergency protection mode. First, the operating mode of the low-voltage withdrawable switchgear is switched to emergency protection mode. In emergency protection mode, the intelligent operation and maintenance system performs the following operations: Determine the emergency protection capacity limit. The rated current of the trolley is 1000 amps, and the emergency protection capacity limit is set to 50% of the rated current, i.e., 500 amps. The intelligent operation and maintenance system sends a trip unit parameter adjustment command to the upstream circuit breaker of the low-voltage withdrawable switchgear, reducing the overload protection setting value from the original 1000 amps to 500 amps. This means that when the load current exceeds 500 amps, the circuit breaker will automatically trip within a specified time, thereby limiting the current flowing through the contacts and reducing the risk of contact overheating. Disable the remote push-out and local push-out operations of the trolley. The intelligent operation and maintenance system sends an operation disable command to the operating mechanism control unit of the trolley, locking the electric propulsion mechanism and the manual propulsion mechanism to prevent any unauthorized personnel from moving the trolley. This is because operating the handcart under abnormally worn guide rail conditions could lead to serious consequences such as the handcart jamming, derailment, or contact damage. Simultaneously, the intelligent maintenance system activates an enhanced locking mode via the electromagnetic lock in the handcart locking mechanism. In enhanced locking mode, the electromagnetic lock's attraction force is increased from the normal value (e.g., 200 Newtons) to an enhanced value (e.g., 400 Newtons), ensuring the handcart will not shift even under accidental vibration or accidental activation. The temperature and position sampling frequencies are switched to a high-frequency sampling mode. In normal operation, the wireless temperature sensor samples once per minute, and the displacement sensor samples once per second. After switching to high-frequency sampling mode, the wireless temperature sensor's sampling frequency increases to once every 10 seconds, and the displacement sensor's sampling frequency increases to 10 times per second. High-frequency sampling can more promptly detect dangerous situations such as rapid temperature increases or abnormal changes in handcart position, gaining valuable time for emergency response.

[0072] In the above embodiment, the intelligent operation and maintenance system generates a comprehensive task work order based on the contact deterioration comprehensive index (1.536), guide rail wear degree (abnormal wear), emergency protection capacity limit (500 amps), and high-frequency sampling mode. The comprehensive task work order includes: work order number (e.g., ZH-2024-003521), work order type (comprehensive task work order - emergency), equipment identification (low-voltage switchgear #3 - handcart #7), fault diagnosis results (contact contact abnormality 0.96, contact deterioration comprehensive index 1.536, guide rail wear degree is abnormal wear), implemented pre-control measures (operation mode is emergency protection mode, current capacity limit is 500 amps, all push-pull-out operations are disabled, monitoring mode is high-frequency sampling), recommended maintenance measures (contact maintenance includes cleaning contact surface, adjusting contact pressure, and checking spring mechanism; guide rail maintenance includes checking guide rail wear, replacing guide rail rollers, and lubricating guide rail surface), and maintenance priority (emergency, response within 24 hours). The intelligent operation and maintenance system simultaneously pushes comprehensive task work orders to the operation and maintenance terminal (the handheld device of the on-site operation and maintenance personnel) and the operation and maintenance management center (the monitoring screen in the dispatch room), ensuring that relevant personnel can be informed of abnormal situations in a timely manner and arrange for handling.

[0073] It should also be noted that the examples of the actual values ​​of all the above parameters are merely exemplary embodiments. The actual values ​​of all the above parameters are not limited to the examples above, and can be adjusted according to specific needs in practical applications.

[0074] This application's embodiments involve synchronously collecting displacement and operating torque data during the operation of a low-voltage withdrawable switchgear trolley. A displacement-torque correspondence is established through time-correlation processing, and torque gradient analysis is performed on the correlated data sequence to identify characteristic locations of torque abrupt changes. By determining whether these characteristic locations are within the displacement range of the contact electrical contact, it is determined whether the torque anomaly is related to contact contact. The degree of contact anomaly is obtained by comparing the contact resistance torque value with the operating torque benchmark value. The intelligent operation and maintenance system further combines the distribution characteristics of the characteristic locations to determine the degree of guide rail wear and integrates the degree of contact anomaly with temperature monitoring data during operation to obtain a comprehensive contact degradation index. Finally, based on the comprehensive contact degradation index and the degree of guide rail wear, differentiated operation and maintenance instructions are generated and corresponding anomaly pre-control operations are executed. This system can proactively identify contact anomalies and guide rail wear anomalies during the trolley operation phase, implementing pre-control measures before a fault occurs.

[0075] The intelligent operation and maintenance system in the embodiments of this invention is described below from the perspective of hardware processing. (See attached document.) Figure 2 , Figure 2 This is a schematic diagram of the physical device structure of an intelligent operation and maintenance system in the embodiments of this application.

[0076] It should be noted that, Figure 2The structure of the intelligent operation and maintenance system shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0077] like Figure 2 As shown, the intelligent operation and maintenance system includes a central processing unit (CPU) 201, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 202 or a program loaded from storage portion 208 into random access memory (RAM) 203, such as executing the methods described in the above embodiments. The RAM 203 also stores...

[0078] It contains various programs and data required for system operation. CPU 201, ROM 202, and RAM 203 are interconnected via bus 204. Input / output (I / O) interface 205 is also connected to bus 204.

[0079] The following components are connected to I / O interface 205: input section 206 including audio input devices, push-button switches, etc.; output section 207 including a liquid crystal display (LCD) and audio output devices, indicator lights, etc.; storage section 208 including a hard disk, etc.; and communication section 209 including a network interface card such as a LAN (Local Area Network) card, modem, etc. Communication section 209 performs communication processing via a network such as the Internet. Drive 210 is also connected to I / O interface 205 as needed. Removable media 211, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 210 as needed so that computer programs read from them can be installed into storage section 208 as needed.

[0080] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing computer programs for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 209, and / or installed from removable medium 211. When the computer program is executed by central processing unit (CPU) 201, it performs the various functions defined in the present invention.

[0081] It should be noted that specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0082] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. Each block in a flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those shown in the drawings.

[0083] Specifically, the intelligent operation and maintenance system of this embodiment includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, it implements the intelligent operation and maintenance method for low-voltage withdrawable switchgear provided in the above embodiment.

[0084] In another aspect, the present invention also provides a computer-readable storage medium, which may be included in the intelligent operation and maintenance system described in the above embodiments; or it may exist independently and not be assembled into the intelligent operation and maintenance system. The storage medium carries one or more computer programs, which, when executed by a processor of the intelligent operation and maintenance system, enable the intelligent operation and maintenance system to implement the intelligent operation and maintenance method for the low-voltage withdrawable switchgear provided in the above embodiments.

[0085] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0086] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for intelligent operation and maintenance of a low-voltage withdrawable switchgear, characterized in that, include: During the operation of the low-voltage withdrawable switchgear, displacement data of the switchgear is collected in real time by displacement sensors installed on the switchgear guide rails, and operating torque data is collected synchronously by torque sensors installed on the switchgear operating mechanism. The displacement data and the operating torque data are correlated over time to obtain a correlated data sequence, which represents the operating torque value of the handcart at different displacement positions. Torque gradient analysis is performed on the associated data sequence to obtain the torque change gradient value at each displacement position, and the displacement position where the torque change gradient value exceeds the target gradient threshold is marked as a feature position point; Based on the mechanical structure parameters of the handcart, the displacement range at which the moving contact of the handcart and the stationary contact seat of the cabinet make initial electrical contact is determined. If the characteristic position point is determined to be within the displacement range, the initial contact position point that matches the starting displacement position of the displacement range is determined from the associated data sequence. The operating torque value of the initial contact position point is used as the operating torque reference value, and the operating torque value at the characteristic position point in the associated data sequence is determined as the contact resistance torque value. The contact resistance torque value is compared and analyzed with the operating torque reference value to obtain the contact anomaly degree. The contact anomaly degree characterizes the degree of deviation of the mechanical fit between the handcart moving contact and the cabinet stationary contact seat. Based on the degree of contact abnormality, perform abnormal pre-control operations on the low-voltage withdrawable switchgear.

2. The method according to claim 1, characterized in that, The step of performing time-correlation processing on the displacement data and the operating torque data to obtain a correlated data sequence specifically includes: Obtain the displacement sampling timestamp sequence of the displacement sensor and the torque sampling timestamp sequence of the torque sensor. The displacement sampling timestamp sequence includes a first timestamp corresponding to each displacement sampling moment, and the torque sampling timestamp sequence includes a second timestamp corresponding to each torque sampling moment. Perform clock synchronization verification on the displacement sensor and the torque sensor to obtain the clock offset between the first timestamp and the second timestamp; The clock offset is compared and analyzed with a preset synchronization tolerance threshold. When the clock offset is greater than the preset synchronization tolerance threshold, the clock offset is used to perform clock compensation correction on the torque sampling timestamp sequence to obtain a target torque sampling timestamp sequence that is synchronized with the clock of the displacement sampling timestamp sequence. Iterate through each first timestamp in the displacement sampling timestamp sequence, and perform the following steps for the currently iterated first timestamp: In the target torque sampling timestamp sequence, find the third timestamp whose time difference with the target timestamp satisfies the preset time matching condition. The target timestamp is the first timestamp currently traversed in the displacement sampling timestamp sequence. The time difference is compared and analyzed with a preset matching time threshold. When the time difference is less than or equal to the preset matching time threshold, the operating torque value corresponding to the third timestamp is matched with the displacement position corresponding to the target timestamp to obtain a first association data pair. When the time difference is greater than the preset matching time threshold, linear interpolation is performed on the operating torque values ​​corresponding to the two fourth timestamps adjacent to the target timestamp in the target torque sampling timestamp sequence to obtain the operating torque value corresponding to the target timestamp. The operating torque value corresponding to the target timestamp is then matched with the displacement position corresponding to the target timestamp to obtain a second association data pair. The first associated data pair and / or the second associated data pair are arranged and combined to generate the associated data sequence.

3. The method according to claim 1, characterized in that, The step of performing torque gradient analysis on the associated data sequence to obtain the torque change gradient value at each displacement position, and marking the displacement positions where the torque change gradient value exceeds the target gradient threshold as feature position points, specifically includes: Multiple displacement sampling points are extracted from the associated data sequence according to a preset displacement sampling interval, and the operating torque value corresponding to each of the multiple displacement sampling points is obtained. A displacement window is established with the displacement position of each displacement sampling point as the center position of the window and the preset window displacement amount as the window length, and a torque data subsequence is extracted from the displacement window of each displacement sampling point; The torque data subsequence is subjected to local linear fitting to obtain the fitted torque slope at each displacement sampling point, and the fitted torque slope is used as the torque change gradient value at each displacement sampling point. The historical torque fluctuation range of the handcart when it slides along the handcart guide rail under no-load conditions is obtained, and the torque fluctuation reference bandwidth of the handcart is determined based on the historical torque fluctuation range. The target gradient threshold is obtained by multiplying the torque fluctuation reference bandwidth by a preset safety margin coefficient. The torque change gradient value of each displacement sampling point is compared with the target gradient threshold. When there is a target displacement sampling point among the multiple displacement sampling points whose absolute value of the torque change gradient value is greater than the target gradient threshold, the target displacement sampling point is marked as a torque change candidate point. The displacement distribution analysis is performed on the torque change candidate points. When there are multiple candidate displacement points that are continuously distributed among the torque change candidate points, the target candidate displacement point that satisfies the preset torque change gradient condition among the multiple candidate displacement points is determined as the feature position point. When the torque change candidate point is an isolated single candidate displacement point, the single candidate displacement point is determined as the feature position point.

4. The method according to claim 3, characterized in that, The determination of the displacement range for initial electrical contact between the moving contact of the handcart and the stationary contact seat of the cabinet based on the mechanical structural parameters of the handcart specifically includes: The mechanical structure parameters of the handcart are obtained from the equipment file of the low-voltage withdrawable switchgear. The mechanical structure parameters include the total stroke length of the handcart, the extension length of the moving contact, and the designed engagement stroke of the contact. The first handcart displacement value is determined when the front end of the handcart's moving contact reaches the socket inlet of the cabinet's stationary contact seat based on the full stroke length of the handcart and the extension length of the moving contact. The first handcart displacement value is then used as the initial electrical contact starting displacement. Add the initial electrical contact start displacement to the designed contact engagement stroke to obtain the second handcart displacement value when the handcart moving contact is fully engaged with the cabinet stationary contact seat. Use the second handcart displacement value as the initial electrical contact termination displacement. Obtain the cumulative number of uses and historical wear detection records of the handcart guide rail, and determine the wear compensation amount of the handcart guide rail based on the cumulative number of uses and the historical wear detection records; The initial electrical contact start displacement and the initial electrical contact end displacement are adjusted using the guide rail wear compensation amount to obtain the target electrical contact start displacement and the target electrical contact end displacement. The displacement range is defined as the displacement interval between the target electrical contact initiation displacement and the target electrical contact termination displacement.

5. The method according to claim 4, characterized in that, The step of performing abnormal pre-control operation on the low-voltage withdrawable switchgear based on the abnormality of the contact points specifically includes: The abnormal contact degree of the contact is compared with a first preset threshold in a second numerical comparison analysis. When the abnormal contact degree of the contact is greater than the first preset threshold, it is determined that the handcart moving contact is in a contact deterioration state, and a contact contact state deterioration warning information is generated. Determine the total number of the feature location points in the associated data sequence, determine the displacement coordinate distribution range of the feature location points based on the total number and the actual location coordinates of the feature location points, and determine the coverage ratio of the displacement coordinate distribution range to the full travel length of the handcart. The average value of the torque change gradient at the feature location point is obtained by averaging the torque change gradient values. The total quantity is compared with the second preset threshold to obtain the quantity comparison analysis result; the coverage ratio is compared with the preset ratio threshold to obtain the ratio comparison analysis result; and the average value of the torque change gradient is compared with the preset gradient threshold to obtain the gradient comparison analysis result. If the total quantity is determined to be greater than the second preset threshold based on the quantity comparison analysis results, the coverage ratio is determined to be greater than the preset ratio threshold based on the ratio comparison analysis results, and the average value of the torque change gradient is determined to be greater than the preset gradient threshold based on the gradient comparison analysis results, then the wear degree of the guide rail of the handcart is determined to be abnormal wear; otherwise, the wear degree of the guide rail is determined to be normal wear. The abnormality pre-control operation is performed on the low-voltage withdrawable switchgear according to the wear degree of the guide rail.

6. The method according to claim 5, characterized in that, The abnormal pre-control operation performed on the low-voltage withdrawable switchgear based on the wear degree of the guide rail specifically includes: The contact temperature data collected by the wireless temperature sensor set at the static contact seat of the cabinet is obtained, and the temperature rise rate of the moving contact of the handcart is determined based on the contact temperature data. A time-series correlation analysis was performed between the temperature rise rate and the contact anomaly degree to obtain a comprehensive contact deterioration index. Differentiated maintenance instructions are generated based on the contact deterioration comprehensive index and the guide rail wear degree, wherein: When the contact deterioration index is greater than a third preset threshold and the guide rail wear is normal, a contact maintenance command is generated. When the contact deterioration index is less than or equal to a third preset threshold and the guide rail wear is abnormal, a guide rail maintenance command is generated. When the contact deterioration index is greater than a third preset threshold and the guide rail wear is abnormal, a combined maintenance instruction including the contact maintenance instruction and the guide rail repair instruction is generated. The abnormal pre-control operation is performed on the low-voltage withdrawable switchgear according to the differentiated operation and maintenance instructions.

7. The method according to claim 6, characterized in that, The step of performing the abnormal pre-control operation on the low-voltage withdrawable switchgear according to the differentiated operation and maintenance instructions specifically includes: Under the contact maintenance command, the target allowable current capacity of the handcart is determined according to the contact deterioration comprehensive index, and the target allowable current capacity is negatively correlated with the contact deterioration comprehensive index; By adjusting the tripping parameters of the upstream circuit breaker of the low-voltage withdrawable switchgear, the actual operating current of the handcart is limited to the target allowable current capacity. The wireless temperature sensor is activated to monitor the temperature of the handcart's moving contact in real time. When the temperature rise rate of the handcart's moving contact is detected to be greater than the preset safety rate, the target allowable current capacity is reduced to the secondary current limiting threshold. A contact maintenance task order is generated based on the contact deterioration comprehensive index, the target allowable current capacity, and the temperature rise rate, and the contact maintenance task order is pushed to the operation and maintenance terminal. Under the guide rail maintenance command, determine the current position of the handcart, and determine the safe range of allowable displacement of the handcart based on the current position of the handcart and the wear degree of the guide rail; When the current location is determined to be the working position, the remote opening and closing function of the handcart circuit breaker is disabled while the local manual opening and closing function is retained, and the enhanced locking mode is activated through the electromagnetic lock in the locking mechanism of the handcart. When the current location is determined to be a test location or an isolation location, all propulsion operations of the handcart are disabled; Based on the wear level of the guide rail, the current position, and the safe position range, a guide rail maintenance task work order is generated and pushed to the operation and maintenance terminal. Under the combined operation and maintenance command, the operation mode of the low-voltage withdrawable switchgear is switched to emergency protection mode; In the emergency protection mode, the target allowable current capacity is reduced to the emergency protection capacity limit; Disable the remote push-pull operation and local push-pull operation of the handcart, and switch the temperature sampling frequency of the moving contact of the handcart and the position sampling frequency of the handcart to high-frequency sampling mode; A comprehensive task work order is generated based on the contact deterioration comprehensive index, the guide rail wear degree, the emergency protection capacity limit, and the high-frequency sampling mode, and the comprehensive task work order is simultaneously pushed to the operation and maintenance terminal and the operation and maintenance management center.

8. An intelligent operation and maintenance system, characterized in that, The intelligent operation and maintenance system includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to cause the intelligent operation and maintenance system to perform the method as described in any one of claims 1-7.

9. A computer-readable storage medium comprising instructions, characterized in that, When the instruction is run on the intelligent operation and maintenance system, it causes the intelligent operation and maintenance system to perform the method as described in any one of claims 1-7.

10. A computer program product, characterized in that, When the computer program product is run on the intelligent operation and maintenance system, the intelligent operation and maintenance system performs the method as described in any one of claims 1-7.

Images