Method and device for identifying poor contact of a circuit breaker trolley in a working position

Abstract

The application provides a method for identifying poor contact of a circuit breaker trolley in a working position, the circuit breaker trolley being located in a medium-voltage switch cabinet, and the method comprises the following steps: acquiring vacuum circuit breaker state data and microswitch state data; determining that the circuit breaker trolley is in a working position according to the vacuum circuit breaker state data and the microswitch state data; acquiring time series data of an ambient temperature of the circuit breaker trolley and real-time temperatures of upper connectors and lower connectors of the circuit breaker trolley; calculating steady-state temperatures of the upper connectors and the lower connectors under a rated current according to the ambient temperature and the time series data of the real-time temperatures; and identifying whether the circuit breaker is in poor contact according to the steady-state temperatures of the upper connectors and the lower connectors under the rated current.

Description

Technical Field

[0001] This application mainly relates to the field of medium-voltage switchgear, and in particular to a method and device for identifying poor contact of a circuit breaker trolley in its working position. Background Technology

[0002] Medium-voltage switchgear is a critical primary device in the operation of power distribution systems and a core component ensuring the safe and reliable operation of these systems. Medium-voltage switchgear requires regular maintenance, and each maintenance procedure necessitates removing the circuit breaker trolley from the switchgear cabinet. After maintenance, the circuit breaker trolley must be moved back to its correct operating position within the cabinet to restore normal operation.

[0003] Existing circuit breaker trolley status verification solutions include: monitoring the circuit breaker trolley position using image data collected by cameras, or monitoring the circuit breaker trolley status using status information assisted by vacuum circuit breakers. These existing solutions can provide information on whether the circuit breaker trolley has been moved, but they only have limited ability to confirm whether the circuit breaker trolley has reached the correct final position, and they cannot determine whether a good electrical connection is maintained between the moving contacts of the circuit breaker trolley and the stationary contacts of the cabinet.

[0004] Even if conventional position monitoring methods determine that the circuit breaker trolley is in the correct operating position, poor contact may still exist between the moving and stationary contacts within the same phase. This poor contact leads to increased contact resistance, which in turn causes abnormal temperature rise at the connector location during current-carrying operation. Over time, this abnormal temperature rise introduces a risk of failure during switchgear operation, potentially leading to switchgear damage, unplanned outages, or safety hazards in the power distribution system. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a method and apparatus for identifying poor contact in the working position of a circuit breaker trolley.

[0006] To achieve the above objectives, this application proposes a method for identifying poor contact in the working position of a circuit breaker trolley, wherein the circuit breaker trolley is located in a medium-voltage switchgear, and the method includes:

[0007] Acquire status data of vacuum circuit breakers and micro switches;

[0008] The circuit breaker trolley is determined to be in the working position based on the vacuum circuit breaker status data and the micro switch status data.

[0009] Acquire time-series data of the ambient temperature of the circuit breaker trolley and the real-time temperatures of the upper and lower connectors of the circuit breaker trolley.

[0010] Calculate the steady-state temperature of the upper and lower connectors under rated current based on the time series data of the ambient temperature and the real-time temperature.

[0011] Based on the steady-state temperature of the upper and lower connectors under rated current, identify whether the circuit breaker has poor contact.

[0012] This application provides a method for identifying poor contact in the working position of a circuit breaker trolley in a medium-voltage switchgear. By calculating the steady-state temperature based on real-time temperature time-series data, the method can predict the final thermal equilibrium temperature reached by the connection point from transient temperature data, without waiting for actual thermal equilibrium, thus achieving early identification of poor contact risk. By combining ambient temperature to normalize the steady-state temperature to the rated current condition, the steady-state temperature under the rated current is determined only by the contact resistance, independent of the actual load level, enabling accurate identification of poor contact under any operating load.

[0013] Optionally, the method further includes:

[0014] Obtain the time series data of the real-time current of the drive motor in the circuit breaker trolley;

[0015] The circuit breaker trolley is determined to be in the working position based on the time series data of the real-time current, the status data of the vacuum circuit breaker, and the status data of the micro switch.

[0016] In some embodiments, the method further includes:

[0017] Acquire real-time images of the circuit breaker trolley;

[0018] The circuit breaker trolley is determined to be in the working position based on the real-time image, the vacuum circuit breaker status data, and the micro switch status data.

[0019] Optionally, the method further includes:

[0020] Acquire real-time images of the circuit breaker trolley and time-series data of the real-time current of the drive motor in the circuit breaker trolley;

[0021] The circuit breaker trolley is determined to be in the working position based on the time series data of the real-time current, the real-time image, the vacuum circuit breaker status data, and the micro switch status data.

[0022] Optionally, calculating the steady-state temperature of the upper and lower connectors under rated current based on the time series data of the ambient temperature and the real-time temperature includes:

[0023] Calculate the steady-state temperature of the upper and lower connectors under real-time current based on the time series data of the real-time temperature.

[0024] The steady-state temperatures of the upper and lower connectors under rated current are calculated based on the ambient temperature and the steady-state temperatures of the upper and lower connectors under real-time current.

[0025] Optionally, identifying whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors at rated current includes:

[0026] Obtain the temperature threshold;

[0027] Compare the steady-state temperature at the rated current with the first threshold.

[0028] When the steady-state temperature at the rated current exceeds the first threshold, the circuit breaker is identified as having poor contact.

[0029] Optionally, identifying whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors at rated current includes:

[0030] In response to determining the three-phase current balance of the medium-voltage switchgear, the highest and lowest steady-state temperature values ​​of the three phases at the same measurement location are compared.

[0031] When the difference between the highest steady-state temperature value and the lowest steady-state temperature value exceeds a second threshold, the circuit breaker is identified as having poor contact.

[0032] This application also proposes a device for identifying poor contact in the working position of a circuit breaker trolley in a medium-voltage switchgear, wherein the circuit breaker trolley is located in the medium-voltage switchgear, and the device includes:

[0033] The first acquisition module acquires the status data of the vacuum circuit breaker and the status data of the micro switch.

[0034] The determination module determines the working position of the circuit breaker trolley based on the vacuum circuit breaker status data and the micro switch status data.

[0035] The second acquisition module acquires time-series data of the ambient temperature of the circuit breaker trolley and the real-time temperatures of the upper and lower connectors of the circuit breaker trolley.

[0036] The calculation module calculates the steady-state temperature of the upper and lower connectors under rated current based on the time series data of the ambient temperature and the real-time temperature.

[0037] The identification module identifies whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors under rated current.

[0038] This application also proposes an electronic device including a processor, a memory, and instructions stored in the memory, wherein the instructions, when executed by the processor, implement the method described above.

[0039] This application also proposes a computer-readable storage medium having computer instructions stored thereon, which, when executed, perform the methods described above.

[0040] This application also proposes a computer program product, including a computer program that, when executed by a processor, implements the method described above. Attached Figure Description

[0041] The accompanying drawings are intended only to illustrate and explain this application and do not limit the scope of this application.

[0042] Figure 1 This is a flowchart of a method for identifying poor contact of a circuit breaker trolley in its working position according to an embodiment of this application;

[0043] Figure 2 This is a schematic diagram of the identification process of a circuit breaker trolley in a working position according to an embodiment of this application;

[0044] Figure 3 This is a schematic diagram of a circuit breaker trolley poor contact identification device in the working position according to an embodiment of this application;

[0045] Figure 4 This is a schematic diagram of an electronic device according to an embodiment of the present application.

[0046] Explanation of reference numerals in the attached figures

[0047] Methods for identifying poor contact in the working position of a 100-speed circuit breaker trolley

[0048] Steps 110, 120, 130, 140

[0049] Steps 201, 202, 203, 204, 205, 206, 207, 208, 209, 2010, 211, 212, 213

[0050] 300 Circuit breaker trolley poor contact identification device in working position

[0051] 310 First Acquisition Module

[0052] 320 Determine Module

[0053] 330 Second Acquisition Module

[0054] 340 Calculation Module

[0055] 350 Recognition Module

[0056] 400 Electronic Devices

[0057] 410 processor

[0058] 420 memory Detailed Implementation

[0059] To provide a clearer understanding of the technical features, objectives, and effects of this application, specific embodiments of this application will now be described with reference to the accompanying drawings.

[0060] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein, and therefore this application is not limited to the specific embodiments described below.

[0061] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0062] This application proposes a method for identifying poor contact in the operating position of a circuit breaker trolley located within a medium-voltage switchgear. The medium-voltage switchgear can be a medium-voltage air-insulated switchgear. The switchgear may include a vacuum circuit breaker, a circuit breaker trolley, and multiple electrical connectors arranged across three phases (phase A, phase B, and phase C). The circuit breaker trolley is a removable unit carrying the moving contact. When the circuit breaker trolley is inserted into the medium-voltage switchgear and placed in the operating position, the moving contact of the trolley engages with the stationary contact installed within the switchgear. Each phase of the switchgear has an upper connector and a lower connector, located at the interface between the moving and stationary contacts. The upper and lower connectors represent critical connection points where poor contact may occur between the moving and stationary contacts.

[0063] The medium-voltage switchgear is also equipped with microswitches. The microswitches are configured to generate different status outputs when the circuit breaker trolley is in different positions, to indicate whether the circuit breaker trolley is currently in the working position or the test position.

[0064] The circuit breaker trolley is equipped with a drive motor, configured to drive the circuit breaker trolley along the guide rail during insertion into the medium-voltage switchgear. A camera is also installed inside the medium-voltage switchgear, configured to capture real-time images of the circuit breaker trolley.

[0065] Multiple temperature sensors can be arranged at the upper and lower connectors of the circuit breaker trolley. The temperature sensors can be arranged at the upper and lower connectors of each of the three phases (phase A, phase B, and phase C), providing a total of six measurement locations. The temperature sensors are configured to collect time-series data of the real-time temperature of the upper and lower connectors. In addition, an ambient temperature sensor is installed in the medium-voltage switchgear and configured to collect the ambient temperature of the circuit breaker trolley.

[0066] Figure 1 This is a flowchart of a method 100 for identifying poor contact of a circuit breaker trolley in its working position according to an embodiment of this application. Figure 1 As shown, method 100 includes:

[0067] Step 110: Obtain the status data of the vacuum circuit breaker and the micro switch;

[0068] Vacuum circuit breaker (VCB) status data indicates whether the VCB is in the open or closed state. This status information can be obtained through sensors or a monitoring system that tracks the operating status of the VCB assembly. For example, a VCB status data of 0 indicates that the VCB is in the closed state, while a data of 1 indicates that the VCB is in the open state.

[0069] The microswitch status data provides information about whether the circuit breaker trolley is in the operating or test position. The test position can include a static test position and a moving test position. The microswitch can be configured to detect the physical presence or absence of the trolley at a specific predetermined position within the switchgear. For example, a microswitch status data of 0 indicates that the circuit breaker trolley is in the test position, and a data of 1 indicates that the circuit breaker trolley is in the operating position.

[0070] Step 120: Determine the working position of the circuit breaker trolley based on the vacuum circuit breaker status data and the micro switch status data;

[0071] The criterion for determining whether the circuit breaker trolley is in the working position based on the vacuum circuit breaker status data and the microswitch status data is as follows: both the vacuum circuit breaker status data and the microswitch status data indicate the working position (i.e., a value of 1). When both conditions are met simultaneously, the circuit breaker trolley is determined to be in the working position. If either condition is not met, it is uncertain whether the circuit breaker trolley is in the working position.

[0072] Step 130: Obtain time series data of the ambient temperature of the circuit breaker trolley and the real-time temperatures of the upper and lower connectors of the circuit breaker trolley.

[0073] The ambient temperature is measured by an ambient temperature sensor and represents the air temperature around the circuit breaker trolley inside the medium-voltage switchgear. The ambient temperature sensor can be placed inside the medium-voltage switchgear away from current-carrying components to ensure that the measured ambient temperature is not affected by connector heating.

[0074] The real-time temperature time-series data is acquired by temperature sensors located at the upper and lower connectors. The time-series data includes a sequence of temperature values ​​acquired continuously from each measurement location or at predetermined time intervals. Each temperature value corresponds to a measurement time, such that the time-series data contains at least two or more temperature measurements acquired from the same measurement location at different times.

[0075] Temperature sensors can be positioned at the upper and lower connectors of each of the three phases, for a total of six measurement locations. Each temperature sensor independently acquires time-series data of its real-time temperature.

[0076] Step 140: Calculate the steady-state temperature of the upper and lower connectors under rated current based on the time series data of ambient temperature and real-time temperature;

[0077] Steady-state temperature refers to the temperature at which the connection reaches thermal equilibrium under the condition that a specific current continuously flows through the upper or lower connector. In actual operation, after the circuit breaker trolley is reinserted into the medium-voltage switchgear and begins current-carrying operation, the temperature at the upper and lower connectors is in a transient process of continuous change and has not yet reached thermal equilibrium. Directly using the instantaneous temperature value collected at a certain moment cannot accurately reflect the final temperature level that the connection will reach. Based on the temperature trend information over time contained in the time series data of real-time temperature, the final thermal equilibrium temperature that the connection will reach is predicted and calculated, thus obtaining a steady-state temperature index representing the final equilibrium state during the transient phase.

[0078] The contact state between the moving and stationary contacts directly determines the magnitude of the contact resistance. Higher contact resistance results in more Joule heat being generated under the same current, thus leading to a higher steady-state temperature at that connection point. Therefore, steady-state temperature constitutes an effective thermal indicator reflecting the quality of the connection.

[0079] The temperature rise at a connection point is proportional to the square of the current flowing through it. Therefore, the same contact condition corresponds to different steady-state temperature values ​​under different real-time currents, making it impossible to use a uniform threshold for judgment. After normalizing the steady-state temperature to the rated current condition, the steady-state temperature under the rated current is determined solely by the contact resistance of the connection point, independent of the actual operating load level, thus constituting a temperature index that purely reflects the connection quality. Based on this normalized temperature index, a uniform temperature threshold can be used to accurately identify poor contact under any operating load.

[0080] Step 150: Identify whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors under rated current.

[0081] Under normal contact conditions, the contact resistance between the moving and stationary contacts is at a low level, and the steady-state temperatures at the upper and lower connectors are within the normal range during current-carrying operation. Under poor contact conditions, the contact resistance increases, leading to increased Joule heating during current-carrying operation and causing an abnormal rise in the steady-state temperature at the corresponding measurement location. By detecting whether there is an abnormal rise in steady-state temperature, it is possible to identify whether there is poor contact at the operating position of the circuit breaker trolley. For example, the steady-state temperature at each measurement location under rated current can be compared with a pre-set judgment benchmark, and the comparison result can be used to determine whether there is poor contact between the moving and stationary contacts at the corresponding location.

[0082] This application provides a method for identifying poor contact in the working position of a circuit breaker trolley in a medium-voltage switchgear. By calculating the steady-state temperature based on real-time temperature time-series data, the method can predict the final thermal equilibrium temperature reached by the connection point from transient temperature data, without waiting for actual thermal equilibrium, thus achieving early identification of poor contact risk. By combining ambient temperature to normalize the steady-state temperature to the rated current condition, the steady-state temperature under the rated current is determined only by the contact resistance, independent of the actual load level, enabling accurate identification of poor contact under any operating load.

[0083] In some embodiments of this application, method 100 further includes:

[0084] Obtain the time series data of the real-time current of the drive motor in the circuit breaker trolley;

[0085] The circuit breaker trolley is in the working position based on the real-time current time series data, vacuum circuit breaker status data, and micro switch status data.

[0086] In these embodiments, a current sensor can be installed in the power supply circuit of the drive motor and configured to measure the real-time current of the drive motor during the insertion of the circuit breaker trolley into the medium-voltage switchgear. The current sensor continuously acquires the current values ​​of the drive motor at a predetermined sampling frequency, forming time-series data of the real-time current.

[0087] The criteria for determining the working position of the circuit breaker trolley based on the time series data of real-time current, the status data of the vacuum circuit breaker, and the status data of the micro switch are as follows: the status data of the vacuum circuit breaker indicates the working position (value 1), the status data of the micro switch indicates the working position (value 1), and the maximum absolute current value in the time series data of real-time current is lower than the predetermined current threshold.

[0088] The aforementioned predetermined current threshold represents the expected maximum current level of the drive motor during normal insertion of the circuit breaker trolley. If the drive motor moves the circuit breaker trolley, the current of the drive motor will exceed this predetermined current threshold. Therefore, comparing the maximum absolute current value of the drive motor with the predetermined current threshold provides auxiliary mechanical confirmation that the circuit breaker trolley has completed its insertion movement, thereby improving the reliability of position confirmation.

[0089] In some embodiments of this application, method 100 further includes:

[0090] Acquire real-time images of the circuit breaker trolley;

[0091] The circuit breaker trolley is determined to be in the working position based on real-time images, vacuum circuit breaker status data, and microswitch status data.

[0092] In these embodiments, the camera is mounted at a fixed location inside the medium-voltage switchgear and configured to acquire real-time images of the circuit breaker trolley after it is inserted into the cabinet. The real-time images represent the visual state of the circuit breaker trolley at the current moment.

[0093] Determining the operating position of the circuit breaker trolley based on real-time images, vacuum circuit breaker status data, and microswitch status data can include comparing the real-time images with pre-stored reference images. The reference image is a standard reference image representing the circuit breaker trolley in the correct operating position. The visual similarity between the real-time image and the reference image is quantitatively assessed by calculating the distance between them. The distance value can be calculated using metrics including, but not limited to, Euclidean distance, structural similarity index, or feature matching distance.

[0094] The criteria for determining that the circuit breaker trolley is in the working position are: the vacuum circuit breaker status data indicates the working position (value 1), the micro switch status data indicates the working position (value 1), and the distance between the real-time image and the reference image is lower than the predetermined image threshold.

[0095] Image comparison provides a visual confirmation channel independent of electrical signals, enabling the detection of positional anomalies that might not be apparent from status signals alone, thereby improving the reliability of position confirmation.

[0096] In some embodiments of this application, method 100 further includes:

[0097] Acquire real-time images of the circuit breaker trolley and time-series data of the real-time current of the drive motor in the circuit breaker trolley;

[0098] The circuit breaker trolley is determined to be in the working position based on the real-time current time series data, real-time images, vacuum circuit breaker status data, and micro switch status data.

[0099] In these embodiments, the criteria for determining that the circuit breaker trolley is in the working position based on the time series data of real-time current, real-time image, vacuum circuit breaker status data and micro switch status data are as follows: the vacuum circuit breaker status data indicates the working position (value 1), and the micro switch status data indicates the working position (value 1), and the distance between the real-time image and the reference image is lower than a predetermined image threshold, and the maximum absolute current value in the time series data of real-time current is lower than a predetermined current threshold.

[0100] This embodiment utilizes all four data sources simultaneously for comprehensive judgment, providing the highest level of confidence in location verification. By simultaneously satisfying all conditions of electrical state data, mechanical current characteristic data, and visual image data, the probability of location misjudgment is minimized.

[0101] In some embodiments of this application, calculating the steady-state temperature of the upper and lower connectors under rated current based on time-series data of ambient temperature and real-time temperature includes:

[0102] The steady-state temperatures of the upper and lower connectors under real-time current are calculated based on the time-series data of real-time temperature.

[0103] The steady-state temperatures of the upper and lower connectors under rated current are calculated based on the ambient temperature and the steady-state temperatures of the upper and lower connectors under real-time current.

[0104] In these embodiments, the steady-state temperatures of the upper and lower connectors under real-time current, calculated based on real-time temperature time-series data, can be expressed by formula (1):

[0105] (1)

[0106] in, and express Time and Temperature measurement at the same location at any given time. express and The time interval between two temperature measurements Indicates the current operating current. Indicates the current operating current The steady-state temperature at the measurement location.

[0107] The steady-state temperatures of the upper and lower connectors under rated current, calculated based on ambient temperature and steady-state temperatures of the upper and lower connectors under real-time current, can be expressed by formula (2):

[0108] (2)

[0109] in, This indicates the steady-state temperature under rated current. Indicates ambient temperature. Indicates the rated current.

[0110] In some embodiments of this application, identifying whether a circuit breaker has poor contact based on the steady-state temperatures of the upper and lower connectors at rated current includes:

[0111] Obtain the temperature threshold;

[0112] Compare the steady-state temperature at rated current with the first threshold;

[0113] When the steady-state temperature at rated current exceeds the first threshold, a circuit breaker contact malfunction is identified.

[0114] In these embodiments, a temperature threshold is first obtained, which is defined as a first threshold in this embodiment. The first threshold represents the maximum permissible steady-state temperature of the upper or lower connector under normal connection conditions under rated current conditions. The first threshold can be predetermined and stored based on the design parameters of the medium-voltage switchgear, the rated temperature rise index of the connector, or type test data.

[0115] The steady-state temperature at rated current is then compared with a first threshold. If the steady-state temperature at rated current exceeds the first threshold, a poor contact is determined to exist between the moving and stationary contacts at that measurement location, identifying a poor contact in the circuit breaker trolley. The poor contact identification result can be transmitted to the operator display, maintenance planning system, or alarm system for timely corrective action.

[0116] If the steady-state temperature under rated current does not exceed the first threshold, the connection at the measurement location is determined to be normal, and the circuit breaker trolley is identified as having good contact.

[0117] In some embodiments of this application, identifying whether a circuit breaker has poor contact based on the steady-state temperatures of the upper and lower connectors at rated current includes:

[0118] Under the condition of determining the three-phase current balance of the medium-voltage switchgear, compare the highest and lowest steady-state temperature values ​​of the three phases at the same measurement location;

[0119] When the difference between the highest and lowest steady-state temperatures exceeds a second threshold, a circuit breaker contact malfunction is identified.

[0120] Specifically, taking the above connector as an example: obtain the steady-state temperature of the connector on phase A under the rated current. Steady-state temperature of the connector at rated current on phase B and the steady-state temperature of the connector on phase C under rated current. The highest steady-state temperature value is determined from the above three values. and minimum steady-state temperature value .

[0121] Calculate the highest steady-state temperature. With the lowest steady-state temperature value The difference between them:

[0122]

[0123] At the highest steady-state temperature With the lowest steady-state temperature value The difference between When the second threshold is exceeded, a faulty contact is identified in the circuit breaker trolley. This indicates the highest steady-state temperature value has been reached. There is poor contact at the measurement location of the phase.

[0124] This cross-phase comparison method utilizes the inherent symmetry of balanced three-phase operation. Under three-phase current balance conditions, if all connections in the three phases are in good contact, the steady-state temperature values ​​at corresponding measurement locations in the three phases (e.g., at the upper connectors of the three phases) are expected to be substantially equal. If there is poor contact at the connector of one phase, the Joule heating generated by the increased contact resistance in that phase increases, resulting in a significantly higher steady-state temperature relative to the other two phases. Therefore, a difference ΔT exceeding a second threshold indicates a phase-specific connection anomaly in that phase.

[0125] Figure 2 This is a schematic diagram illustrating the identification process of a circuit breaker trolley in a working position according to an embodiment of this application. Figure 2 As shown, the identification process may include:

[0126] Step 201, Begin;

[0127] Step 202: Obtain the status data of the vacuum circuit breaker and the micro switch;

[0128] Step 203: Determine whether the status data of the vacuum circuit breaker and the status data of the micro switch both indicate the working position; if yes, proceed to step 204; otherwise, proceed to step 213.

[0129] Step 204: Determine whether the current of the drive motor can be obtained. If yes, proceed to step 205; otherwise, proceed to step 207.

[0130] Step 205: Obtain the time series of the current values ​​of the drive motor;

[0131] Step 206: Determine whether the maximum value in the time series of current values ​​is less than the threshold current; if yes, proceed to step 207; otherwise, proceed to step 213.

[0132] Step 207: Determine whether the image of the circuit breaker trolley can be obtained. If yes, proceed to step 208; otherwise, proceed to step 211.

[0133] Step 208: Obtain an image of the circuit breaker trolley;

[0134] Step 209: Calculate the distance between the image of the circuit breaker trolley and the reference image;

[0135] Step 210: Determine if the distance is less than the threshold; if yes, proceed to step 211; otherwise, proceed to step 213.

[0136] Step 211: Identify whether the circuit breaker trolley has poor contact based on the predicted steady-state temperature under the rated current;

[0137] Step 212: Determine if there is a risk of poor contact.

[0138] Step 213, End.

[0139] This application also proposes an identification device for poor contact of the circuit breaker trolley in the working position of a medium-voltage switchgear, wherein the circuit breaker trolley is located in the medium-voltage switchgear. Figure 3 This is a schematic diagram of a circuit breaker trolley contact malfunction identification device 300 in the working position according to an embodiment of this application. Figure 3 As shown, the device 300 includes:

[0140] The first acquisition module 310 acquires vacuum circuit breaker status data and micro switch status data;

[0141] Module 320 determines the working position of the circuit breaker trolley based on the vacuum circuit breaker status data and the micro switch status data.

[0142] The second acquisition module 330 acquires time series data of the ambient temperature of the circuit breaker trolley and the real-time temperatures of the upper and lower connectors of the circuit breaker trolley.

[0143] Calculation module 340 calculates the steady-state temperature of the upper and lower connectors under rated current based on time series data of ambient temperature and real-time temperature;

[0144] The identification module 350 identifies whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors under rated current.

[0145] This application also proposes an electronic device 400. Figure 4 This is a schematic diagram of an electronic device 400 according to an embodiment of this application. Figure 4As shown, the electronic device 400 includes a processor 410 and a memory 420. The memory 420 stores instructions, which, when executed by the processor 410, implement the method 100 described above.

[0146] This application also proposes a computer-readable storage medium having computer instructions stored thereon, which, when executed, perform the method 100 described above.

[0147] This application also proposes a computer program product, including a computer program that, when executed by a processor, performs the method 100 described above.

[0148] Some aspects of the methods and apparatus of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLCs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this application may manifest as a computer product residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compact discs (CDs), digital multifunction discs (DVDs), etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0149] Flowcharts are used herein to illustrate the operations performed by the method according to embodiments of this application. It should be understood that the preceding operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from them.

[0150] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0151] The above description is merely an illustrative embodiment of this application and is not intended to limit the scope of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of this application shall fall within the scope of protection of this application.

[0152] In this patent application, nouns and pronouns relating to people are not limited to specific genders.

Claims

1. A method (100) for identifying poor contact of a circuit breaker trolley in its working position, wherein the circuit breaker trolley is located in a medium-voltage switchgear, characterized in that, The method (100) includes: Acquire (110) vacuum circuit breaker status data and micro switch status data; Based on the vacuum circuit breaker status data and the micro switch status data, it is determined (120) that the circuit breaker trolley is in the working position; Obtain time series data of the ambient temperature of the circuit breaker trolley and the real-time temperatures of the upper and lower connectors of the circuit breaker trolley (130); Calculate (140) the steady-state temperature of the upper and lower connectors under rated current based on the time series data of the ambient temperature and the real-time temperature; Based on the steady-state temperature of the upper and lower connectors at rated current, identify (150) whether the circuit breaker has poor contact.

2. The method (100) according to claim 1, characterized in that, The method (100) further includes: Obtain the time series data of the real-time current of the drive motor in the circuit breaker trolley; The circuit breaker trolley is determined to be in the working position based on the time series data of the real-time current, the status data of the vacuum circuit breaker, and the status data of the micro switch.

3. The method (100) according to claim 1, characterized in that, The method (100) further includes: Acquire real-time images of the circuit breaker trolley; The circuit breaker trolley is determined to be in the working position based on the real-time image, the vacuum circuit breaker status data, and the micro switch status data.

4. The method (100) according to claim 1, characterized in that, The method (100) further includes: Acquire real-time images of the circuit breaker trolley and time-series data of the real-time current of the drive motor in the circuit breaker trolley; The circuit breaker trolley is determined to be in the working position based on the time series data of the real-time current, the real-time image, the vacuum circuit breaker status data, and the micro switch status data.

5. The method (100) according to claim 1, characterized in that, The steady-state temperatures of the upper and lower connectors under rated current are calculated based on the time-series data of the ambient temperature and the real-time temperature, including: Calculate the steady-state temperature of the upper and lower connectors under real-time current based on the time series data of the real-time temperature. The steady-state temperatures of the upper and lower connectors under rated current are calculated based on the ambient temperature and the steady-state temperatures of the upper and lower connectors under real-time current.

6. The method (100) according to claim 1, characterized in that, Identifying whether the circuit breaker has poor contact based on the steady-state temperatures of the upper and lower connectors at rated current includes: Obtain the temperature threshold; Compare the steady-state temperature at the rated current with the first threshold. When the steady-state temperature at the rated current exceeds the first threshold, the circuit breaker is identified as having poor contact.

7. The method (100) according to claim 1, characterized in that, Identifying whether the circuit breaker has poor contact based on the steady-state temperatures of the upper and lower connectors at rated current includes: In response to determining the three-phase current balance of the medium-voltage switchgear, the highest and lowest steady-state temperature values ​​of the three phases at the same measurement location are compared. When the difference between the highest steady-state temperature value and the lowest steady-state temperature value exceeds a second threshold, the circuit breaker is identified as having poor contact.

8. A device (300) for identifying poor contact of a circuit breaker trolley in a medium-voltage switchgear operating position, wherein the circuit breaker trolley is located in the medium-voltage switchgear, characterized in that, The device (300) includes: The first acquisition module (310) acquires the vacuum circuit breaker status data and the micro switch status data; The determination module (320) determines that the circuit breaker trolley is in the working position based on the vacuum circuit breaker status data and the micro switch status data. The second acquisition module (330) acquires the time series data of the ambient temperature of the circuit breaker trolley and the real-time temperature of the upper and lower connectors of the circuit breaker trolley. The calculation module (340) calculates the steady-state temperature of the upper connector and the lower connector under rated current based on the time series data of the ambient temperature and the real-time temperature; The identification module (350) identifies whether the circuit breaker has poor contact based on the steady-state temperature of the upper and lower connectors under rated current.

9. An electronic device (400) includes a processor (410), a memory (420) and instructions stored in the memory (420), wherein the instructions, when executed by the processor (410), implement the method (100) as claimed in any one of claims 1-7.

10. A computer-readable storage medium having stored thereon computer instructions that, when executed, perform the method (100) according to any one of claims 1-7.

11. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, performs the method (100) of any one of claims 1-7.

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