A load box life diagnosis method, system, computer device and storage medium

Abstract

The present application relates to the field of load box, disclose a kind of load box life diagnostic method, system, computer equipment and storage medium, comprising the following steps: obtaining load box operating data;According to the operating data obtained, intercept several stable working periods;The response delay index, dynamic impedance drift index and harmonic distortion rate in each power stable working period are calculated;The damage degree of each power stable working period is added to obtain the cumulative damage degree, the cumulative damage degree is compared with the first damage degree threshold and the second damage degree threshold, to determine the load box working state.The present application filters operating data, eliminates non-stable working periods that affect the reliability of the judgment, ensures that the operating data obtained can be used to accurately determine the working condition of the load box, by setting the first damage degree threshold and the second damage degree threshold, the working condition of the load box is divided, the health condition of the load box is judged from different aspects, to ensure that the use efficiency of the load box is maximized.

Description

Technical Field

[0001] This invention relates to the field of load cells, and particularly to a method, system, computer device, and storage medium for diagnosing the lifespan of a load cell. Background Technology

[0002] As a key testing equipment used in power distribution networks to simulate loads, test protection devices, and calibrate metering equipment, load cells are subjected to complex operating conditions such as intermittent high loads, periodic start-stop cycles, and fluctuations in ambient temperature and humidity. As a result, the performance of key components such as internal resistive elements, heat dissipation structures, and connection terminals degrades over time.

[0003] Current mainstream methods mostly rely on macroscopic operating data such as cumulative power-on time, maximum load duration, or surface temperature rise, or only select local signal characteristics such as current harmonic content and voltage sag frequency for independent threshold judgment. They fail to establish the intrinsic correlation between response characteristics, impedance stability, and nonlinear distortion, three typical aging characteristics. This results in insufficient ability to identify the composite degradation mechanisms such as thermal fatigue, contact deterioration, and insulation aging of resistive elements inside the load cell, and easily leads to "misjudgment of condition" or "missed detection".

[0004] Furthermore, current judgment methods do not rigorously screen the operating data of the load bank. They often directly extract a fixed-length window from the original current sequence to calculate characteristic quantities, or use whether the current amplitude falls within a certain static tolerance band as the basis for stability judgment. Such methods cannot adapt to the significant differences in response curve morphology under different load levels, heat dissipation conditions, and aging degrees. As a result, the extracted indicators such as response delay, impedance drift, and harmonic distortion are severely affected by transient disturbances, reducing the representativeness and comparability of the data. This leads to a large error in judging the life of the load bank, affecting actual use. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned problems by providing a load cell life diagnosis method, system, computer equipment and storage medium, which solves the problems of low accuracy, inaccurate judgment and easy misjudgment in existing judgment methods.

[0006] To achieve this objective, the present invention adopts the following technical solution: A method for diagnosing the lifespan of a load cell includes the following steps: Real-time acquisition and caching of load balancer operation data; Several stable working periods are extracted based on the acquired operational data; Calculate the response delay index, dynamic impedance drift index, and harmonic distortion rate during each power stable operating period. The degree of damage during each power stable operating period is obtained based on the obtained response delay index, dynamic impedance drift index, and harmonic distortion rate. The cumulative damage is obtained by summing the damage levels during each stable power operation period. The cumulative damage is then compared with the first damage threshold and the second damage threshold to determine the operating status of the load cell.

[0007] Preferably, the process of selecting the stable working period includes the following steps: Set consecutive sliding window periods and sort them, keeping the number of sampling points consistent within each sliding window period; Calculate the real-time root mean square rate of change of current at all sampling points within each sliding window period; Set an oscillation threshold. The sliding window is a steady-state window if and only if the real-time root mean square rate of change of current at all sampling points within the sliding window is less than the oscillation threshold. All steady-state windows are filtered out, and 10 consecutively numbered steady-state windows are taken as a group of power stable operating periods to obtain several stable operating periods.

[0008] Obtaining the response latency index includes the following steps: Get the timestamp of the command issued by the host computer; Set the current threshold and amplitude threshold; Real-time acquisition of current values; when the difference between the current values ​​of five consecutive sampling points and the current threshold is less than the amplitude threshold, the time of the first sampling point among the five consecutive sampling points is recorded as the response time. The difference between the timestamp of the command issued by the host computer and the response time is the response latency index.

[0009] Preferably, obtaining the dynamic impedance drift index includes the following steps: Obtain the total number of sampling points during the stable working period; Calculate the effective resistance value at each sampling point; The dynamic impedance drift index is calculated based on the effective resistance value.

[0010] Preferably, obtaining the harmonic distortion rate includes the following steps: Acquire current data from all sampling points during the stable operating period; The acquired current data is subjected to FFT transformation; Set the frequency range and find the modulus corresponding to the frequency range in the transformed spectrum array; The harmonic distortion rate is calculated based on the modulus.

[0011] Preferably, obtaining the cumulative damage degree includes the following steps: By setting sensitivity weights for response delay index, dynamic impedance drift index, and harmonic distortion rate, the damage degree for each power stable operating period is calculated. The cumulative damage degree is obtained by summing the damage degree of each power stable operating period through the Weibull distribution; When the cumulative damage reaches the first damage threshold, the load cell will issue an alarm.

[0012] Preferably, the second damage threshold is greater than the first damage threshold, and setting the second damage threshold includes the following steps: Set target power and safe climb rate thresholds; When the actual power reaches 10% of the target power during the load shedding process after the contactor contacts of the load box close, record the power of the load box at this time, which is the first power. When the actual power reaches 90% of the target power during the load shedding process after the contactor of the load box closes, the power of the load box at this time is recorded as the second power. The power ramp-up rate is calculated using the first power and the second power. If the power ramp-up rate is less than the safe ramp-up rate threshold, the cumulative damage at this time is recorded as the second damage threshold. When the cumulative damage of the load cell reaches the second damage threshold, the operation of the load cell is stopped.

[0013] A load cell life diagnostic system, used in the aforementioned load cell life diagnostic method, includes: The data module is used to acquire various data during the operation of the load cell and to calculate an index for judging the lifespan of the load cell based on the acquired data. The judgment module is used to identify stable working periods and determine the lifespan of the load cell based on the data obtained from the data module. The control module is used to control the power of the load bank and receive signals from the judgment module to control the operation and shutdown of the load bank. The storage module is used to save the historical operating data of the load cell.

[0014] A computer device, comprising: Memory and processor; The memory is used to store at least one program; When the program is executed by the processor, the processor implements the diagnostic method described above.

[0015] A storage medium includes a computer program that, when executed by a processor, implements the diagnostic method described above.

[0016] The contribution of this invention is as follows: This invention filters operational data to eliminate unstable operating periods that could affect reliability assessment, and selects stable operating periods from the filtered data to ensure that the obtained operational data can be used to accurately determine the working status of the load cell.

[0017] The operating status of the load bank is evaluated by using multi-dimensional indices (response delay index, dynamic impedance drift index, and harmonic distortion rate) to ensure that there are no misjudgments or missed detections.

[0018] By setting a first damage threshold and a second damage threshold, the working condition of the load cell is classified, and the working condition of the load cell is evaluated from different aspects to ensure that the utilization efficiency of the load cell is maximized. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the load cell life diagnosis method of the present invention; Figure 2 This is a flowchart illustrating the capture of the stable operating period of the load cell in this invention. Figure 3 This is a schematic diagram of the structure of the computer device and storage medium in this invention. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying 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. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0023] like Figure 1 As shown in the figure, this embodiment discloses a load cell life diagnosis method, including the following steps: The system acquires and caches load bank operating data, including current, voltage, power, and frequency. By analyzing the operating data and capturing the stable operating periods of the load bank, it avoids interference from unstable operating period data in the calculation of subsequent indices (response delay index, dynamic impedance drift index, harmonic distortion rate, damage degree, cumulative damage degree, etc.). This ensures that the obtained response delay index, dynamic impedance drift index, harmonic distortion rate, and other data are accurate and can be used to accurately identify and judge the health status of the load bank.

[0024] Specifically, the extraction of the stable working period includes, for example: Figure 2 The following steps are shown: Set consecutive sliding window periods (50ms-60ms) and sort them, keeping the number of sampling points (2200-2800) consistent within each sliding window period; Calculate the real-time root mean square rate of change of current at all sampling points within each sliding window period; Set an oscillation threshold (2.5%-3%). The sliding window is a steady-state window if and only if the real-time root mean square rate of change of current at all sampling points within the sliding window is less than the oscillation threshold. All steady-state windows are filtered out, and 10 consecutively numbered steady-state windows are taken as a group of power stable operating periods, resulting in several groups of stable operating periods.

[0025] To further explain this embodiment, after obtaining the stable operating period, the response delay index, dynamic impedance drift index, and harmonic distortion rate are calculated for each stable operating period. The operating status of the load bank is comprehensively judged by the response delay index, dynamic impedance drift index, and harmonic distortion rate. Specifically, obtaining the response delay index includes the following steps: Get the timestamp of the command issued by the host computer; Set the current threshold (select the rated current for the corresponding power) and the amplitude threshold (5%). Real-time acquisition of current values; when the difference between the current value and the current threshold of five consecutive sampling points is less than the amplitude threshold, the time of the first sampling point among these five sampling points is recorded as the response time. The difference between the timestamp of the command issued by the host computer and the response time is the response latency index.

[0026] The formula for calculating the response latency index is as follows:

[0027] in, In response to the latency index, This is the timestamp for the instructions issued by the host computer. For the response time.

[0028] To further explain, obtaining the dynamic impedance drift index includes the following steps: Obtain the total number of sampling points during the stable working period; Calculate the effective resistance value at each sampling point; The dynamic impedance drift index is calculated based on the effective resistance value.

[0029] The formula for calculating the dynamic impedance drift index is as follows:

[0030] in, The effective resistance value, It is the number of sampling points within each steady-state window. The instantaneous voltage value at the sampling point. The instantaneous current value at the sampling point;

[0031] in, This refers to the dynamic impedance drift index. The nominal resistance value. The temperature coefficient of resistance. For radiator temperature, This refers to the standard ambient temperature.

[0032] To further explain, obtaining the harmonic distortion rate includes the following steps: Acquire current data from all sampling points during the stable operating period; The acquired current data is preprocessed by multiplying it by a Hanning window function to prevent edge spectrum leakage. Perform FFT transformation on the preprocessed current data; Set the frequency range (e.g., 50Hz, 100Hz, 150Hz...), and find the modulus of the corresponding frequency range in the transformed spectrum array; The harmonic distortion rate is calculated based on the modulus.

[0033] The formula for calculating harmonic distortion rate is as follows:

[0034] in, Harmonic distortion rate, The length is the module length.

[0035] After obtaining the response delay index, dynamic impedance drift index, and harmonic distortion rate for each stable operating period, the damage degree for each stable operating period is calculated. Specifically, the formula for calculating the damage degree is as follows:

[0036] in, For the degree of damage, To address the sensitive weights of the response latency exponent, As a sensitive weight for the dynamic impedance drift index, This is the sensitive weight for harmonic distortion rate.

[0037] After obtaining the damage levels for each stable operating period, sum them up to obtain the cumulative damage level. The formula for calculating the cumulative damage level is as follows:

[0038] in, For cumulative damage, , The degree of damage during each stable working period.

[0039] To further explain, the first damage threshold is determined by the following formula:

[0040] in, The first damage threshold, The rated nominal life of the load cell. The average health score over the load cell's lifespan. This is shape data. It's important to note here that... The value is adjusted according to the working environment; for example, in a normal environment, The value is 85, in extreme environments. The value should be appropriately reduced by 15%-20%.

[0041] To further explain, the health status of the load bank is determined by its cumulative damage level. Since each power-on or power change (load increase or decrease) will cause lifespan damage to the load bank, when it accumulates to a certain level, the load bank will either operate poorly or experience poor contact or circuit burnout, affecting the testing of the current to be measured. This invention determines the working status of the load bank by comparing its cumulative damage level with a first damage threshold. Specifically, when the cumulative damage level of the load bank is less than the first damage threshold, it indicates that the load bank is in good condition and can continue to be used. If the cumulative damage level of the load bank reaches the first damage threshold, it indicates that the load bank is no longer in its optimal working condition and may be at risk of damage, requiring constant monitoring of the load bank's working status.

[0042] To further explain, when the load cell reaches the first damage threshold, to ensure safety, the load cell can be replaced or continued to be used. Considering cost and continuity of work, it is necessary to further evaluate the working status of the load cell to confirm whether it can continue to operate. At this time, a second damage threshold can be used for judgment. Specifically, the second damage threshold is greater than the first damage threshold, and the setting of the second damage threshold includes the following steps: Set the target power and safe climb rate threshold (95%). When the power reaches 10% of the target power during the load shedding process after the contactor contacts of the load box close, record the actual power of the load box at this time, which is the first power. When the power reaches 90% of the target power during the load shedding process after the contactor contacts of the load box are closed, the actual power of the load box at this time is recorded as the second power. The power ramp-up rate is calculated using the first power and the second power, and the calculation formula is as follows:

[0043] in, Power ramp-up rate, For the target power, The actual power at 90% of the target power. The actual power when the target power is 10%.

[0044] If the power ramp-up rate is less than the safe ramp-up rate threshold, then the cumulative damage at this point is recorded as the second damage threshold. When the cumulative damage level of the load cell reaches the second damage threshold, it indicates that the load cell has developed health problems such as response delay and stuttering, which will affect the normal operation of the load cell and require shutdown for repair.

[0045] A load cell life diagnostic system, used in the aforementioned load cell life diagnostic method, includes: The data module is used to acquire various data during the operation of the load bank and calculate indices (response delay index, dynamic impedance drift index, harmonic distortion rate, damage degree, cumulative damage degree, etc.) based on the acquired data. The judgment module is used to identify stable working periods and determine the lifespan of the load cell based on the data obtained from the data module. The control module is used to control the power of the load bank and receive signals from the judgment module to control the operation and shutdown of the load bank. The storage module is used to save the historical data of the load cell.

[0046] like Figure 3 As shown, a computer device includes: Memory and processor; The memory is used to store at least one program; When the program is executed by the processor, the processor implements the diagnostic method described above.

[0047] A storage medium includes a computer program that, when executed by a processor, implements the diagnostic method described above.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] Although the present invention has been disclosed through the above embodiments, the scope of protection of the present invention is not limited thereto. Any modifications or substitutions made to the above components without departing from the concept of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. A method for diagnosing the lifespan of a load cell, characterized in that, Includes the following steps: Real-time acquisition and caching of load balancer operation data; Several stable working periods are extracted based on the acquired operational data; Calculate the response delay index, dynamic impedance drift index, and harmonic distortion rate during each power stable operating period. The degree of damage during each power stable operating period is obtained based on the obtained response delay index, dynamic impedance drift index, and harmonic distortion rate. The cumulative damage is obtained by summing the damage levels during each stable power operation period. The cumulative damage is then compared with the first damage threshold and the second damage threshold to determine the operating status of the load cell.

2. The load cell life diagnosis method according to claim 1, characterized in that, Extracting the stable working period includes the following steps: Set consecutive sliding window periods and sort them, keeping the number of sampling points consistent within each sliding window period; Calculate the real-time root mean square rate of change of current at all sampling points within each sliding window period; Set an oscillation threshold. The sliding window is a steady-state window if and only if the real-time root mean square rate of change of current at all sampling points within the sliding window is less than the oscillation threshold. All steady-state windows are filtered out, and 10 consecutively numbered steady-state windows are taken as a group of power stable operating periods to obtain several stable operating periods.

3. The load cell life diagnosis method according to claim 2, characterized in that, Obtaining the response latency index includes the following steps: Obtain the timestamp of the command issued by the host computer; Set the current threshold and amplitude threshold; Real-time acquisition of current values; when the difference between the current values ​​of five consecutive sampling points and the current threshold is less than the amplitude threshold, the time of the first sampling point among the five consecutive sampling points is recorded as the response time. The difference between the timestamp of the command issued by the host computer and the response time is the response latency index.

4. The load cell life diagnosis method according to claim 3, characterized in that, Obtaining the dynamic impedance drift index includes the following steps: Obtain the total number of sampling points during the stable working period; Calculate the effective resistance value at each sampling point; The dynamic impedance drift index is calculated based on the effective resistance value.

5. The load cell life diagnosis method according to claim 4, characterized in that, Obtaining the harmonic distortion rate includes the following steps: Acquire current data from all sampling points during the stable operating period; The acquired current data is subjected to FFT transformation; Set the frequency range and find the modulus corresponding to the frequency range in the transformed spectrum array; The harmonic distortion rate is calculated based on the modulus.

6. The load cell life diagnosis method according to claim 5, characterized in that, Obtaining the cumulative damage includes the following steps: By setting sensitivity weights for response delay index, dynamic impedance drift index, and harmonic distortion rate, the damage degree for each power stable operating period is calculated. The cumulative damage degree is obtained by summing the damage degree of each power stable operating period through the Weibull distribution; When the cumulative damage reaches the first damage threshold, the load cell will issue an alarm.

7. The load cell life diagnosis method according to claim 6, characterized in that, The second damage threshold is greater than the first damage threshold. Setting the second damage threshold includes the following steps: Set target power and safe climb rate thresholds; When the actual power reaches 10% of the target power during the load shedding process after the contactor contacts of the load box close, record the power of the load box at this time, which is the first power. When the actual power reaches 90% of the target power during the load shedding process after the contactor of the load box closes, the power of the load box at this time is recorded as the second power. The power ramp-up rate is calculated using the first power and the second power. If the power ramp-up rate is less than the safe ramp-up rate threshold, the cumulative damage at this time is recorded as the second damage threshold. When the cumulative damage of the load cell reaches the second damage threshold, the operation of the load cell is stopped.

8. A load cell life diagnostic system, used in the load cell life diagnostic method as described in any one of claims 1-7, characterized in that, include: The data module is used to acquire various data during the operation of the load cell and to calculate an index for judging the lifespan of the load cell based on the acquired data. The judgment module is used to identify stable working periods and determine the lifespan of the load cell based on the data obtained from the data module. The control module is used to control the power of the load bank and receive signals from the judgment module to control the operation and shutdown of the load bank. The storage module is used to save the historical data of the load cell.

9. A computer device, characterized in that, include: Memory and processor; The memory is used to store at least one program; When the program is executed by a processor, the processor implements the diagnostic method as described in any one of claims 1-7.

10. A storage medium comprising a computer program, characterized in that: When the computer program is executed by the processor, it implements the diagnostic method as described in any one of claims 1-7.

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