A monitoring method and device for resistance value of a switch cabinet, an electronic device and a storage medium

Abstract

The application provides a switch cabinet resistance value monitoring method and device, electronic equipment and storage medium, and relates to the technical field of switch cabinets. The method comprises the following steps: obtaining a vibration signal collected by an acceleration sensor installed at a connecting position of a contact arm or a bus of a to-be-tested switch cabinet, and obtaining a current loop resistance value and a loop resistance change rate of the to-be-tested switch cabinet; identifying whether the loop resistance value of the switch cabinet is truly increased based on the loop resistance change rate and a harmonic vibration amplitude feature quantity of the vibration signal; and if it is determined that the loop resistance value of the switch cabinet is truly increased, determining whether to perform a warning action based on the size relationship between the loop resistance value and a preset resistance value. Through the combination of the vibration feature and the resistance value change criterion, the true increase of the resistance and the decline of the heat dissipation performance are distinguished, false judgments are avoided, and the accuracy of the evaluation and judgment of the switch cabinet resistance value is improved.

Description

Technical Field

[0001] This application relates to the field of switchgear technology, and more specifically, to a method, device, electronic device, and storage medium for monitoring the resistance value of a switchgear. Background Technology

[0002] In recent years, with the deepening application of artificial intelligence technology in the field of power equipment condition monitoring, online monitoring methods for conductive circuit resistance based on physical models and data-driven approaches have gradually emerged. Physical models are often established based on the relationship between temperature difference, current, and resistance. However, temperature difference is influenced by many factors. If the resistance value estimated by the model is directly relied upon for condition judgment, the system often only provides a binary judgment of "abnormal," failing to distinguish whether the change in reading is caused by poor contact, material aging, or sensor malfunction. This limitation makes it difficult for maintenance personnel to take timely and targeted measures, affecting the reliability of power equipment condition assessment. Summary of the Invention

[0003] The purpose of this application is to provide a method, device, electronic device and storage medium for monitoring the resistance value of switchgear, so as to solve the technical problems of inaccurate evaluation and judgment of the resistance value of existing switchgear and poor fault identification performance.

[0004] In a first aspect, the present invention provides a method for monitoring the resistance value of a switchgear. The method includes acquiring vibration signals collected by an accelerometer installed at the contact arm or busbar connection of the switchgear under test, and acquiring the current loop resistance value and the loop resistance change rate of the switchgear under test; identifying whether the loop resistance value of the switchgear has actually increased based on the loop resistance change rate and the harmonic vibration amplitude characteristics of the vibration signal; and determining whether to execute an early warning action based on the magnitude between the loop resistance value and a preset resistance value if it is determined that the loop resistance value of the switchgear has actually increased.

[0005] In an optional implementation, before determining whether to execute a warning action based on the difference between the loop resistance value and a preset resistance value, the following method is further included: Obtain the temperature difference coefficient value of the switch cabinet under test, as well as the temperature difference coefficient values ​​of other switch cabinets; Determine whether there is a deviation between the temperature difference coefficient value of the switchgear under test and the temperature difference coefficient value of other switchgears; If it does not exist, proceed with the steps to confirm whether to execute the warning action; The other switchgear and the switchgear under test are located in the same substation, and the equipment conditions and operating conditions of the other switchgear and the switchgear under test are matched.

[0006] In an optional implementation, the step of identifying whether the circuit resistance of the switchgear has actually increased based on the rate of change of circuit resistance and the harmonic vibration amplitude characteristics of the vibration signal specifically includes: Determine whether the rate of change of circuit resistance is greater than the alarm threshold for the rate of change of resistance; If the value is greater than the resistance change rate alarm threshold, then determine whether the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold. If the value exceeds the alarm threshold for amplitude characteristic, then it is determined that the circuit resistance value of the switchgear has actually increased. If the value is less than the alarm threshold of the amplitude characteristic quantity, it is determined that the performance of the heat dissipation system of the switch cabinet has deteriorated. If the resistance change rate alarm threshold is less than the value of the resistance change rate alarm threshold, and the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold, then poor contact is determined to be inside the switch cabinet.

[0007] In an optional implementation, the harmonic vibration amplitude characteristic of the vibration signal is calculated in the following manner: Determine the vibration amplitude of the preset frequency band of the vibration signal and the load current value of the switchgear ; Calculate the characteristic quantity of harmonic vibration amplitude .

[0008] In an optional implementation, the step of determining whether there is a deviation between the temperature difference coefficient value of the switchgear under test and the temperature difference coefficient values ​​of other switchgears specifically includes: Determine the median value of the temperature difference coefficient of the switchgear under test within a preset time period, and use it as the first value; Determine the median of the current temperature difference coefficient values ​​for all other switchgear cabinets as the second value; If the first value exceeds the second value by several times the standard deviation, and no other switchgear reports any abnormalities, then a long-term deviation is confirmed.

[0009] In an optional implementation, for each switchgear in the substation, the temperature difference coefficient value of the switchgear within a preset time period is linearly fitted, and the slope value of the fitted value is determined. If all switch cabinets have the same slope value sign, then the acquisition channel drift is determined, and the temperature sensor of the switch cabinet is drift corrected. If the relative deviation of the slope value corresponding to a switch cabinet is greater than the preset deviation, an anomaly for that switch cabinet will be reported.

[0010] In an optional implementation, the temperature difference coefficient value is calculated in the following manner. : ; ; in, Sampling time, , This represents the total number of switch cabinets. For switch cabinets exist The internal temperature value at that moment. For switch cabinets exist The ambient temperature value at that moment, For switch cabinets exist The load current value at any given time.

[0011] Secondly, the present invention provides a device for monitoring the resistance value of a switchgear, the device comprising: The acquisition module is used to acquire vibration signals collected by accelerometers installed at the contact arms or busbar connections of the switchgear under test, as well as to acquire the current loop resistance value and the rate of change of loop resistance of the switchgear under test. The identification module is used to identify whether the circuit resistance value of the switchgear has actually increased based on the rate of change of circuit resistance and the characteristic quantity of harmonic vibration amplitude of the vibration signal. The execution module is used to determine whether to perform an early warning action based on the difference between the loop resistance value and the preset resistance value if it is determined that the loop resistance value of the switchgear has actually increased.

[0012] Thirdly, the present invention provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of the switch cabinet resistance value monitoring method as described in any of the foregoing embodiments.

[0013] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the method for monitoring the resistance value of a switchgear as described in any of the foregoing embodiments.

[0014] This application provides a method for monitoring the resistance value of a switchgear. The method includes acquiring vibration signals collected by accelerometers installed at the contact arms or busbar connections of the switchgear under test, and acquiring the current loop resistance value and the rate of change of loop resistance of the switchgear under test. Based on the rate of change of loop resistance and the harmonic vibration amplitude characteristics of the vibration signal, the method identifies whether the loop resistance value of the switchgear has actually increased. If it is determined that the loop resistance value of the switchgear has actually increased, the method determines whether to execute an early warning action based on the difference between the loop resistance value and a preset resistance value. By combining vibration characteristics and resistance value changes as criteria, the method distinguishes between a genuine increase in resistance and a decrease in heat dissipation performance, avoiding misjudgments and improving the accuracy of switchgear resistance value assessment. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating a method for monitoring the resistance value of a switchgear, provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a switch cabinet resistance value monitoring device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0017] Increased resistance in the conductive circuits of switchgear is a major cause of equipment overheating, aging, and malfunctions. Traditional methods rely on power outage testing, which cannot provide real-time monitoring and is prone to missing faults occurring during power outage intervals. Existing circuit resistance estimations are typically based on calculations using resistance change functions. ; Here This represents the temperature difference between the inside and outside of the switch cabinet. This is the load current value. The estimated internal resistance of the circuit is given. This refers to the rotational speed of the cooling fan in the switchgear. , These are preset coefficients. The preset coefficients here... , It can be set to fixed or dynamic settings, without any restrictions.

[0018] In existing technologies, it is common to determine whether the resistance in the circuit has increased based on whether the currently calculated R exceeds the threshold, and then issue an early warning. However, in a physical sense, it is impossible to distinguish whether the increase is due to a larger contact resistance (increased R) or a change in heat dissipation conditions (change in A / B).

[0019] Based on this, this application provides a method, apparatus, electronic device, and storage medium for monitoring the resistance value of a switch cabinet.

[0020] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0021] Example 1 Figure 1 A flowchart illustrating a method for monitoring the resistance value of a switchgear, provided in an embodiment of this application. Figure 1As shown, this application provides a method for monitoring the resistance value of switchgear, applicable to the monitoring and early warning of switchgear in substations. For each switchgear, data acquisition and loop resistance estimation can be performed according to a preset frequency. Furthermore, an accelerometer installed at each switchgear contact arm or busbar connection collects vibration signals, performs a Fast Fourier Transform on the vibration signals, and extracts the vibration amplitude characteristics of the 100Hz and higher harmonic frequency bands. Specifically, the accelerometer can be a piezoelectric accelerometer, monitoring vibration signals in the 50Hz~2kHz frequency band.

[0022] Specifically, the accelerometer here can also be positioned in the center area of ​​the flange of the stationary contact support insulator in the circuit breaker compartment of the switchgear. The sensor's sensitive axis (Z-axis) points perpendicularly to the cabinet beam (i.e., along the main vibration transmission direction). A 0.1 mm thick conductive silver paste is applied between the sensor housing and the flange to eliminate contact gaps and provide electromagnetic shielding.

[0023] In addition, the switchgear here is also equipped with load current sensors, temperature sensors, etc. Among them, the load current sensor is used to monitor the real-time load current flowing through the main circuit. It can collect single-phase or three-phase data and can be installed on the main busbar on the incoming or outgoing side of the switchgear.

[0024] Temperature sensors can be installed downstream of the heat dissipation duct inside the cabinet or behind the baffle near the circuit breaker pole area to collect the air temperature inside the switchgear. Sensors for collecting the external ambient temperature can be installed on wall-mounted points in a well-ventilated public area inside the substation, away from heat sources.

[0025] Meanwhile, the fan speed value can be acquired by a sensor or indirectly calculated by the PWM frequency / feedback signal output from the fan driver.

[0026] In one feasible implementation, the monitoring method may include: S1. Obtain the vibration signal collected by the accelerometer installed at the contact arm or busbar connection of the switch cabinet under test, and obtain the current loop resistance value and loop resistance change rate of the switch cabinet under test.

[0027] In step S1, the load current value of the switchgear, the rotational speed of the switchgear's cooling fan, the internal air temperature of the switchgear, and the external ambient temperature can be collected to calculate the temperature difference between the inside and outside of the switchgear. The current loop resistance value is then calculated based on the resistance change function. .

[0028] Here, other methods can also be used to estimate the loop resistance value, such as based on a pre-trained LSTM model, etc.

[0029] For example, the load current of the switchgear, the current speed of the fan, the temperature difference between the inside and outside of the switch, and the loop resistance value at the previous moment can be input into a pre-trained LSTM model to obtain the current loop resistance value or a preset coefficient output by the model. , .

[0030] The rate of change of loop resistance here can be calculated by dividing the difference between the current loop resistance value and the previous loop resistance value by the time interval. Alternatively, other short-term windows (such as the last 5 minutes) or long-term windows (such as the last 24 hours of normal operation) can be defined for calculating the rate of change of loop resistance; there are no restrictions here.

[0031] S2. Based on the rate of change of loop resistance and the characteristic quantity of harmonic vibration amplitude of vibration signal, identify whether the loop resistance value of switchgear has actually increased.

[0032] In step S2, the harmonic vibration amplitude characteristic quantity can be obtained by extracting the amplitude of the vibration signal in the 100Hz frequency band or the broadband energy of 100Hz~500Hz as the harmonic vibration amplitude characteristic quantity.

[0033] Here, the steps for identifying whether the circuit resistance of the switchgear has actually increased, based on the rate of change of circuit resistance and the harmonic vibration amplitude characteristics of the vibration signal, specifically include: Determine whether the rate of change of circuit resistance is greater than the alarm threshold for the rate of change of resistance; If the value is greater than the resistance change rate alarm threshold, then determine whether the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold. If the value exceeds the alarm threshold for amplitude characteristic, then it is determined that the circuit resistance value of the switchgear has actually increased. If the value is less than the alarm threshold of the amplitude characteristic quantity, it is determined that the performance of the heat dissipation system of the switch cabinet has deteriorated. If the resistance change rate alarm threshold is less than the value of the resistance change rate alarm threshold, and the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold, then poor contact is determined to be inside the switch cabinet.

[0034] The resistance change rate alarm threshold here can be set to 10%~15%, and can be fine-tuned based on historical data from the device. In a preferred embodiment, the resistance change rate alarm threshold can be set to 12%.

[0035] To avoid short-term fluctuations in resistance calculations caused by sudden changes in load current, a duration judgment can be added. For example, the "significant increase" flag can only be triggered when the resistance increases for more than N consecutive sampling periods (e.g., 3 consecutive periods, each period being 1 minute).

[0036] In one feasible implementation, the harmonic vibration amplitude characteristic can be the amplitude of the vibration signal in the 100Hz frequency band.

[0037] By establishing a baseline for vibration amplitude under healthy conditions. For example, the median can be calculated from the 100Hz vibration amplitude during the initial operation of the equipment or during a period without abnormalities after the most recent maintenance. and standard deviation .

[0038] When the following two conditions are met, it can be determined that the characteristic quantity of harmonic vibration amplitude has increased significantly: ； ; in, For switch cabinet exist Amplitude at 100Hz frequency band at any given time. This is the alarm threshold for amplitude characteristic, and its value can be set to 30%~50%.

[0039] In another feasible embodiment, the harmonic vibration amplitude characteristic of the vibration signal can also be calculated in the following way: Determine the vibration amplitude of the preset frequency band of the vibration signal and the load current value of the switchgear Calculate the characteristic quantity of harmonic vibration amplitude. .

[0040] Since an increase in load current itself leads to an increase in conductor electrodynamic force, it may cause a slight increase in 100Hz vibration. To eliminate this effect, the vibration-current ratio can be defined as a characteristic quantity of harmonic vibration amplitude. This, in turn, helps to identify the true cause of the predicted increase in loop resistance.

[0041] In this embodiment, the characteristic quantity of harmonic vibration amplitude can be calculated based on historical data. The median, as the benchmark .like If the amplitude characteristic value exceeds the alarm threshold, it can be determined that the amplitude characteristic value of harmonic vibration has increased significantly. In this case, the alarm threshold for amplitude characteristic value can be set to 40% (because the effect of the square of the current has been removed, the change threshold can be slightly higher).

[0042] S3. If it is determined that the circuit resistance value of the switchgear has actually increased, then determine whether to execute the warning action based on the difference between the circuit resistance value and the preset resistance value.

[0043] In steps S2 and S3, if a significant increase in resistance is detected and a synchronous significant increase in the characteristic value of harmonic vibration amplitude is detected, it can be determined that "the contact resistance of the conductive circuit has actually increased", and the alarm branch is entered.

[0044] If the resistance value increases significantly, but the characteristic value of harmonic vibration amplitude does not change significantly, it can be determined that "the performance of the heat dissipation system has deteriorated" (such as fan aging, dust accumulation on heat sinks, filter blockage, etc.). The system records this diagnosis but does not trigger an abnormal resistance alarm; it only needs to suggest that maintenance personnel check the heat dissipation system. This is because when heat dissipation deteriorates (such as fan aging or filter blockage), the vibration spectrum will not change significantly.

[0045] If the resistance value does not change significantly, but the vibration amplitude increases significantly, it is determined that there may be early contact problems (such as poor contact between the moving and stationary contacts of the handcart, loose bolts at the busbar connection, etc.) but they have not yet manifested as a significant increase in resistance, and the system will issue a warning. This is because when the contact becomes loose or the surface is oxidized, causing an increase in resistance, the alternating current passing through the loose interface will generate a nonlinear arc micro-discharge, which will excite abundant high-order harmonic vibrations (mainly manifested as an enhancement of the 100Hz harmonic component).

[0046] This application provides a method for monitoring the resistance value of a switchgear. By combining vibration characteristics to monitor the resistance value of the switchgear online, it can accurately identify the actual increase in resistance, eliminate false alarms caused by heat dissipation problems, and identify more detailed reasons for the increase in resistance value, thereby providing more accurate alarms and clearer maintenance guidance information.

[0047] Example 2 In one embodiment of this application, in order to further eliminate the impact of long-term sensor drift in the system, a horizontal comparison baseline of multiple switch cabinets can be established to avoid systematic offsets (such as zero drift and gain changes) that occur after long-term operation of current transformers, temperature sensors, and speed sensors, which would affect the accuracy of loop resistance value prediction.

[0048] In this embodiment, multiple switchgear units of the same model and load type within the same substation can be clustered together. The temperature difference coefficient value of each cluster is calculated periodically (e.g., during light load periods in the early morning each day). : ; ; in, Sampling time, , This represents the total number of switch cabinets. For switch cabinet exist The internal temperature value at that moment. For switch cabinet exist The ambient temperature value at that moment, For switch cabinets exist The load current value at any given time.

[0049] Furthermore, before determining whether to execute an early warning action based on the difference between the loop resistance value and the preset resistance value, the temperature difference coefficient value of the switch cabinet under test, as well as the temperature difference coefficient values ​​of other switch cabinets, are obtained.

[0050] Determine whether there is a deviation between the temperature difference coefficient value of the switch cabinet under test and the temperature difference coefficient value of other switch cabinets. If there is no deviation, proceed to the step of confirming whether to execute the warning action.

[0051] The step of determining whether there is a deviation between the temperature difference coefficient value of the switchgear under test and that of other switchgear can be specifically included in determining the median of the temperature difference coefficient values ​​of the switchgear under test over a preset period of time, as the first value. The median of the current temperature difference coefficient values ​​of all other switchgear can be determined as the second value. If the first value exceeds the second value by several times the standard deviation, and no other switchgear reports any abnormalities, then a long-term deviation is determined to exist.

[0052] Among them, the other switchgear and the switchgear under test are located in the same substation, and the equipment conditions and operating conditions of the other switchgear and the switchgear under test are matched. The switchgear under test and the other switchgear belong to the same cluster.

[0053] For each switchgear in the substation, a linear regression is performed on the temperature difference coefficient value of that switchgear within a preset time period, and the slope value of the regression is determined. If the slope values ​​corresponding to all switchgears have the same sign, it is determined that the acquisition channel is drifted, and the temperature sensor of the switchgear is corrected for drift. If the relative deviation of the slope value corresponding to a switchgear is greater than the preset deviation, an anomaly is reported for that switchgear.

[0054] For each cluster, if the temperature difference coefficient value of a certain switch cabinet deviates from the cluster median by more than 3 times the standard deviation for a long period of time, while other cabinets are normal, it can be determined that the temperature sensor of that switch cabinet has drifted and needs to be calibrated.

[0055] If the temperature difference coefficient values ​​of all switch cabinets drift slowly in the same direction at the same time, it can be determined that the common sensor (such as the ambient temperature sensor) or the current acquisition channel has drifted, and the system needs to readjust the baseline.

[0056] Specifically, for sensors that drift, correction coefficients can be derived based on the cluster's median or variance, and these correction coefficients can be used to correct the data collected by the sensors online.

[0057] In this way, by automatically detecting and compensating for sensor drift, the stability of the system's long-term monitoring can be guaranteed.

[0058] Example 3 Figure 2 This is a schematic diagram of a device for monitoring the resistance value of a switchgear, provided as an embodiment of this application. Figure 2 As shown, based on the same inventive concept, this application also provides a switch cabinet resistance value monitoring device 20, the device comprising: The acquisition module 210 is used to acquire vibration signals collected by accelerometers installed at the contact arms or busbar connections of the switchgear under test, as well as to acquire the current loop resistance value and the rate of change of loop resistance of the switchgear under test. The identification module 220 is used to identify whether the circuit resistance value of the switchgear has actually increased based on the rate of change of circuit resistance and the characteristic quantity of harmonic vibration amplitude of the vibration signal. The execution module 230 is used to determine whether to perform an early warning action based on the difference between the loop resistance value and the preset resistance value if it is determined that the loop resistance value of the switch cabinet has actually increased.

[0059] In a preferred embodiment, before determining whether to execute a warning action based on the difference between the loop resistance value and the preset resistance value, the execution module 230 is further configured to obtain the temperature difference coefficient value of the switch cabinet under test, as well as the temperature difference coefficient values ​​of other switch cabinets. Determine whether there is a deviation between the temperature difference coefficient value of the switchgear under test and the temperature difference coefficient value of other switchgears; If it does not exist, proceed with the steps to confirm whether to execute the warning action; The other switchgear and the switchgear under test are located in the same substation, and the equipment conditions and operating conditions of the other switchgear and the switchgear under test are matched.

[0060] In a preferred embodiment, the identification module 220 is specifically used to determine whether the rate of change of the loop resistance is greater than the alarm threshold for the rate of change of resistance. If the value is greater than the resistance change rate alarm threshold, then determine whether the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold. If the value exceeds the alarm threshold for amplitude characteristic, then it is determined that the circuit resistance value of the switchgear has actually increased. If the value is less than the alarm threshold of the amplitude characteristic quantity, it is determined that the performance of the heat dissipation system of the switch cabinet has deteriorated. If the resistance change rate alarm threshold is less than the value of the resistance change rate alarm threshold, and the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold, then poor contact is determined to be inside the switch cabinet.

[0061] In a preferred embodiment, the harmonic vibration amplitude characteristic of the vibration signal is calculated by the identification module 220 in the following manner: Determine the vibration amplitude of the preset frequency band of the vibration signal and the load current value of the switchgear ; Calculate the characteristic quantity of harmonic vibration amplitude .

[0062] In a preferred embodiment, the identification module 220 is further configured to determine the median of the temperature difference coefficient values ​​of the switchgear under test within a preset time period, as the first value; Determine the median of the current temperature difference coefficient values ​​for all other switchgear cabinets as the second value; If the first value exceeds the second value by several times the standard deviation, and no other switchgear reports any abnormalities, then a long-term deviation is confirmed.

[0063] In a preferred embodiment, the identification module 220 is further configured to perform linear fitting on the temperature difference coefficient value of each switchgear in the substation within a preset time period, and determine the fitted slope value. If all switch cabinets have the same slope value sign, then the acquisition channel drift is determined, and the temperature sensor of the switch cabinet is drift corrected. If the relative deviation of the slope value corresponding to a switch cabinet is greater than the preset deviation, an anomaly for that switch cabinet will be reported.

[0064] In a preferred embodiment, the identification module 220 calculates the temperature difference coefficient value in the following manner. : ; ; in, Sampling time, , This represents the total number of switch cabinets. For switch cabinets exist The internal temperature value at that moment. For switch cabinets exist The ambient temperature value at that moment, For switch cabinets exist The load current value at any given time.

[0065] Example 4 Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 3 As shown, the electronic device 300 includes a processor 310, a memory 320, and a bus 330.

[0066] The memory 320 stores machine-readable instructions that can be executed by the processor 310. When the electronic device 300 is running, the processor 310 and the memory 320 communicate via the bus 330. When the machine-readable instructions are executed by the processor 310, the steps of a switch cabinet resistance value monitoring method as described in the above method embodiment can be executed. For specific implementation details, please refer to the method embodiment, which will not be repeated here.

[0067] Example 5 This application also provides a computer-readable storage medium storing a computer program. When the computer program is run by a processor, it can execute the steps of a switch cabinet resistance value monitoring method as described in the above method embodiments. For specific implementation details, please refer to the method embodiments, which will not be repeated here.

[0068] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0069] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0070] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0071] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0072] It should be noted that if the function is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0073] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0074] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for monitoring the resistance value of a switchgear, characterized in that, The method includes: The vibration signal collected by the accelerometer installed at the contact arm or busbar connection of the switch cabinet under test is obtained, as well as the current loop resistance value and the rate of change of loop resistance of the switch cabinet under test. Based on the rate of change of the loop resistance and the harmonic vibration amplitude characteristic of the vibration signal, the step of identifying whether the loop resistance value of the switchgear has actually increased is specifically included: determining whether the rate of change of the loop resistance is greater than a resistance change rate alarm threshold; if it is greater than the resistance change rate alarm threshold, determining whether the harmonic vibration amplitude characteristic of the vibration signal is greater than an amplitude characteristic alarm threshold; if it is greater than the amplitude characteristic alarm threshold, determining that the loop resistance value of the switchgear has actually increased; if it is less than the amplitude characteristic alarm threshold, determining that the heat dissipation system performance of the switchgear has deteriorated; if it is less than the resistance change rate alarm threshold, and the harmonic vibration amplitude characteristic of the vibration signal is greater than the amplitude characteristic alarm threshold, determining that there is poor contact inside the switchgear. If it is determined that the loop resistance value of the switchgear has actually increased, then based on the magnitude between the loop resistance value and the preset resistance value, it is determined whether to execute a warning action; before the step of determining whether to execute a warning action based on the magnitude between the loop resistance value and the preset resistance value, the method further includes: Obtain the temperature difference coefficient value of the switch cabinet under test, as well as the temperature difference coefficient values ​​of other switch cabinets; Determine whether there is a deviation between the temperature difference coefficient value of the switchgear under test and the temperature difference coefficient value of other switchgears; If it does not exist, proceed to the step of determining whether to execute the warning action; The other switchgear and the switchgear under test are located in the same substation, and the equipment conditions and operating conditions of the other switchgear and the switchgear under test are matched. The temperature difference coefficient value is calculated in the following way. : ； ； in, Sampling time, , This represents the total number of switch cabinets. For switch cabinet exist The internal temperature value at that moment. For switch cabinet exist The ambient temperature value at that moment, For switch cabinet exist The load current value at any given time.

2. The method according to claim 1, characterized in that, The harmonic vibration amplitude characteristic of the vibration signal is calculated in the following way: Determine the vibration amplitude of the preset frequency band of the vibration signal. and the load current value of the switchgear ; Calculate the characteristic quantity of harmonic vibration amplitude .

3. The method according to claim 1, characterized in that, The step of determining whether there is a deviation between the temperature difference coefficient value of the switchgear under test and the temperature difference coefficient values ​​of other switchgears specifically includes: Determine the median value of the temperature difference coefficient of the switchgear under test within a preset time period, and use it as the first value; Determine the median of the current temperature difference coefficient values ​​for all other switchgear cabinets, and use it as the second value; If the first value exceeds the second value by several times the standard deviation, and no other switchgear reports any abnormalities, then a long-term deviation is determined to exist.

4. The method according to claim 3, characterized in that, For each switchgear in the substation, the temperature difference coefficient value of the switchgear within a preset time period is linearly fitted, and the slope value of the fitted value is determined. If the slope values ​​corresponding to all switch cabinets have the same sign, then the acquisition channel drift is determined, and the temperature sensor of the switch cabinet is drift corrected. If the relative deviation of the slope value corresponding to a switch cabinet is greater than the preset deviation, an anomaly of the switch cabinet shall be reported.

5. A device for monitoring the resistance value of a switchgear, characterized in that, The method for monitoring the resistance value of a switchgear according to any one of claims 1 to 4, the apparatus comprising: The acquisition module is used to acquire vibration signals collected by accelerometers installed at the contact arms or busbar connections of the switchgear under test, as well as to acquire the current loop resistance value and the rate of change of loop resistance of the switchgear under test. The identification module is used to identify whether the circuit resistance value of the switchgear has actually increased based on the circuit resistance change rate and the harmonic vibration amplitude characteristics of the vibration signal. The execution module is used to determine whether to perform an early warning action based on the difference between the loop resistance value and the preset resistance value if it is determined that the loop resistance value of the switch cabinet has actually increased.

6. An electronic device, characterized in that, include: The device includes a processor, a memory, and a bus. The memory stores machine-readable instructions that the processor can execute. When the electronic device is running, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of the method for monitoring the resistance value of the switch cabinet as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method for monitoring the resistance value of the switchgear as described in any one of claims 1 to 4.

Images