A method for state assessment of an electricity meter

Abstract

This application relates to the technical field of equipment status evaluation, and particularly to a method for evaluating the status of an electric energy meter. The method includes: dividing the voltage signal curve of the working voltage of the electric energy meter within a target time period to obtain a plurality of voltage signal segments; determining a first difference degree value according to the difference degree of the durations of different voltage signal segments, and determining a second difference degree value according to the difference degree of the voltages at different moments within the same voltage signal segment; determining a third difference degree value according to the DTW distance between adjacent voltage signal segments, and taking the mean value of the first difference degree value, the second difference degree value, and the third difference degree value as the target evaluation value; obtaining the average failure interval duration of the electric energy meter within a historical time period, and obtaining the status evaluation result of the electric energy meter according to the target evaluation value and the average failure interval duration. Through the above technical solution, it is possible to more conveniently evaluate the status of the electric energy meter.

Description

Technical Field

[0001] This application relates to the technical field of equipment status assessment, and particularly to a method for assessing the status of an electric energy meter. Background Art

[0002] An electric energy meter can measure the electrical energy consumption in a circuit by measuring the work done by the current at the test node of the device to be measured within a certain period of time. An electric energy meter with remote communication capabilities can also transmit the power consumption data to the management system of the power company in real time; by monitoring and analyzing the power consumption situation, the electric energy meter can also enable users to more intuitively understand the power consumption situation, so as to take corresponding energy-saving measures.

[0003] For example, an electronic electric energy meter samples the voltage and current signals in the circuit through voltage and current transformers, and converts the sampled analog signals into digital signals through an analog / digital converter; the digital signal processor processes the digital signals, calculates the product of the voltage and current, and obtains the instantaneous power value; by integrating the instantaneous power over time, the consumed electrical energy is obtained; the electric energy meter can also display the calculated electrical energy value through a display screen.

[0004] When the electric energy meter measures electrical energy, it has a specific working voltage range. For example, the working voltage of a common single-phase electric energy meter may be within 220V±10%, that is, within the voltage range of 198V to 242V, the electric energy meter can achieve relatively accurate measurement of electrical energy.

[0005] When the status of the electric energy meter is abnormal, it may cause the working voltage of the electric energy meter to be in an unstable state. If the electric energy meter works at an unstable working voltage for a long time, it may accelerate the aging of the internal components of the electric energy meter and shorten the service life of the electric energy meter. Therefore, it is necessary to assess the status of the electric energy meter to ensure that the electric energy meter works within a relatively stable working voltage range. Summary of the Invention

[0006] To achieve the evaluation of the state of the electricity meter, the present application provides a method for evaluating the state of the electricity meter, including: obtaining the voltage signal curve of the working voltage of the electricity meter within the target time period, performing zero-crossing detection on the voltage signal curve to obtain multiple voltage zero positions, and taking the segments where a preset number of consecutive voltage zero positions in time sequence are located as candidate signal segments; in the case where the duration of the candidate signal segment is greater than or equal to the first preset duration, taking the candidate signal segment as the voltage signal segment; in the case where the duration of the candidate signal segment is less than the first preset duration, merging multiple adjacent candidate signal segments with a duration less than the first preset duration to obtain the voltage signal segment; determining the first difference degree value according to the difference degree of different voltage signal segments in duration, and determining the second difference degree value according to the difference degree of voltages at different moments within the same voltage signal segment; determining the third difference degree value according to the DTW distance between adjacent voltage signal segments, and taking the average value of the first difference degree value, the second difference degree value, and the third difference degree value as the target evaluation value; obtaining the average time between failures of the electricity meter within the historical time period, and obtaining the reliability value of the electricity meter according to the target evaluation value and the average time between failures, so as to output the state evaluation result of the electricity meter by using the reliability value; the reliability value is used to represent the time interval between the current moment and the predicted moment when the electricity meter fails next time.

[0007] In this way, by obtaining the voltage signal curve of the working voltage of the electricity meter within the target time period and performing periodic detection on the voltage signal curve, the voltage signal segments with periodicity in the voltage signal curve can be determined, and the reliability value of the electricity meter can be determined based on the average time between failures of the electricity meter according to the difference situation of the voltage signal segments, so as to obtain the state evaluation result of the electricity meter.

[0008] Optionally, the first difference degree value is determined in the following manner: , where H is the first difference degree value, M is the number of voltage signal segments, norm is the normalization processing function, is the duration of the i-th voltage signal segment, is to take the absolute value.

[0009] Optionally, the second difference degree value is determined in the following manner: , where E is the second difference degree value, M is the number of voltage signal segments, norm is the normalization processing function, f is the sampling frequency of the voltage signal, is the duration of the i-th voltage signal segment, is the j-th voltage in the i-th voltage signal segment, is the average value of the voltages within the i-th voltage signal segment, is to take the absolute value.

[0010] Optionally, the third degree of difference value is determined as follows: , where G is the third degree of difference value, M is the number of voltage signal segments, N is the preset neighborhood radius, norm is the normalization function, is the DTW distance between the i-th voltage signal segment and the n-th other voltage signal segment within the neighborhood of the i-th voltage signal segment.

[0011] The DTW distance between two adjacent voltage signal segments can better reflect the degree of difference between the two voltage signal segments.

[0012] Optionally, obtaining the reliability value of the electric energy meter according to the target evaluation value and the mean time between failures includes: performing an exponential operation on the square of the target evaluation value using an exponential function with the natural constant as the base to obtain an exponential operation value; multiplying the reciprocal of the exponential operation value by the mean time between failures to obtain the reliability value; the reliability value is used to characterize the time interval between the current moment and the predicted moment when the next failure of the electric energy meter occurs.

[0013] Optionally, the mean time between failures of the electric energy meter in the historical time period is obtained as follows: determining the operating duration of the electric energy meter in the historical time period, and determining the number of failures of the electric energy meter during the operating duration; taking the ratio of the operating duration to the number of failures as the mean time between failures.

[0014] Optionally, using the reliability value to output the state evaluation result of the electric energy meter includes: when the time interval characterized by the reliability value between the current moment and the predicted moment when the next failure of the electric energy meter occurs is greater than or equal to the second preset duration, prompting that the state evaluation result of the electric energy meter is good.

[0015] Optionally, using the reliability value to output the state evaluation result of the electric energy meter includes: when the time interval characterized by the reliability value between the current moment and the predicted moment when the next failure of the electric energy meter occurs is less than the second preset duration, outputting a prompt message; the prompt message is at least used to prompt the predicted moment when the next failure of the electric energy meter occurs.

[0016] When the time interval characterized by the reliability value between the current moment and the predicted moment when the next failure of the electric energy meter occurs is less than the second preset duration, it is possible to realize an early warning of the moment when the electric energy meter may fail.

[0017] Optionally, the method further includes: for a target voltage signal segment among multiple voltage signal segments with a duration different from the average duration, the duration of the target voltage signal segment can be resampled to the average duration; the average duration is equal to the average of the durations of all voltage signal segments.

[0018] The technical solution provided by the embodiment of the present application may include the following beneficial effects: By obtaining the voltage signal curve of the electric energy meter within the target time period and performing periodic detection on the voltage signal curve to determine the voltage signal segments with periodicity in the voltage signal curve; according to the difference situation of the voltage signal segments and the average failure interval duration of the electric energy meter in the historical time period, the reliability value of the electric energy meter can be obtained, which can more conveniently realize the evaluation of the state of the electric energy meter.

[0019] For the voltage signal segments with a duration equal to the average duration, according to the difference values of the voltage signals at the corresponding positions of different voltage signal segments, the target evaluation value is determined. The target evaluation value can better characterize the difference degree between different voltage signal segments, so as to obtain a more accurate reliability value of the electric energy meter and better realize the evaluation of the state of the electric energy meter.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flowchart of a method for evaluating the state of an electric energy meter shown according to an exemplary embodiment. DETAILED DESCRIPTION

[0022] First, a brief introduction to the application scenario of the embodiment of the present application is given. In the application scenario of the present application, when there is an abnormality in the components of the electric energy meter, it may cause the working voltage of the electric energy meter to be in an unstable state, thereby affecting the measurement result of the electric energy by the electric energy meter; or, when the electric energy meter works under an unstable working voltage, it will accelerate the damage of the components in the electric energy meter, thereby further affecting the measurement result of the electric energy by the electric energy meter. Therefore, it is necessary to evaluate the state of the electric energy meter to ensure the working state of the electric energy meter.

[0023] In view of the above technical problems, the embodiment of the present application provides a method for evaluating the state of an electric energy meter, Figure 1 is a flowchart of a method for evaluating the state of an electric energy meter shown according to an exemplary embodiment. The method for evaluating the state of an electric energy meter provided by the embodiment of the present application can be applied to a terminal device for monitoring the electric energy meter, such as Figure 1 as shown, the method includes the following steps.

[0024] In step S101, obtain the voltage signal curve of the working voltage of the electric energy meter within the target time period, and divide the voltage signal curve to obtain a plurality of voltage signal segments.

[0025] The voltage signal curve includes multiple voltage signals of the electricity meter within the target time period. When the electricity meter is working, the working voltage may have a certain periodicity. By dividing the voltage signal curve to obtain multiple voltage signal segments, the periodicity of the voltage signal can be analyzed based on the obtained multiple pressure signal segments.

[0026] It should be noted that the voltage signal curve obtained in the embodiments of the present application can be the voltage signal curve after filtering the original voltage signal curve of the working voltage of the electricity meter within the target time period; the filtering process can be realized, for example, by wavelet transform or adaptive filter, etc. The embodiments of the present application do not limit the specific algorithm of the filtering process.

[0027] When the electricity meter is working with a relatively stable working voltage period, the durations of multiple voltage segments in the voltage signal curve of the obtained working voltage are close to each other. For example, the durations of multiple voltage segments are the same; while when the operating state of the electricity meter fails or may fail, the period of the working voltage when the electricity meter is working may fluctuate. Therefore, by dividing the voltage signal curve to obtain multiple voltage signal segments, it helps to provide data support for the reliability of the electricity meter.

[0028] Zero-crossing detection can be performed on the voltage signal curve to obtain multiple voltage zero positions. The segments where a preset number of consecutive voltage zero positions in time sequence are located are used as candidate signal segments; when the duration of the candidate signal segment is greater than or equal to the first preset duration, the candidate signal segment is used as the voltage signal segment; when the duration of the candidate signal segment is less than the first preset duration, multiple adjacent candidate signal segments with a duration less than the first preset duration are merged to obtain the voltage signal segment.

[0029] The voltage zero position usually represents the moment when the voltage waveform switches from one half-cycle to the next half-cycle. Therefore, the voltage zero position can be used as a reliable basis for analyzing the periodicity of the working voltage of the electricity meter; by performing zero-crossing detection on the voltage signal curve, the zero-crossing points of the voltage signal in the voltage signal curve can be determined, so that the periodic change of the voltage signal of the working voltage of the electricity meter can be accurately determined.

[0030] The first preset duration can be set according to actual needs. For example, the first preset duration can be between 15 ms and 30 ms.

[0031] The preset number can be set according to actual needs. For example, the preset number can be between 3 and 6; by selecting the segments where a preset number of consecutive voltage zero positions are located as candidate signal segments, it can ensure that the obtained segments have potential periodicity, thereby improving the accuracy of the subsequent processing process.

[0032] When the duration of the candidate signal segment is greater than or equal to the first preset duration, the candidate signal segment can more effectively represent the periodicity of the working voltage of the electric energy meter. The selected candidate signal segment has a high representativeness in terms of duration, and the candidate signal segment can be used as the voltage signal segment.

[0033] When the duration of the candidate signal segment is less than the first preset duration, it indicates that the selected candidate signal may be a part of the periodic segment of the working voltage of the electric energy meter. If there are other candidate signal segments with a duration less than the first preset duration in the neighborhood of the candidate signal segment with a duration less than the first preset duration, then multiple candidate signal segments with a duration less than the first preset duration and adjacent to each other can be merged to obtain the voltage signal segment, so that the obtained voltage signal segment after merging can effectively represent the periodic characteristics of the working voltage of the electric energy meter.

[0034] In step S102, the first difference degree value is determined according to the difference degree of the durations of different voltage signal segments, and the second difference degree value is determined according to the difference degree of the voltages at different moments within the same voltage signal segment.

[0035] For example, when the electric energy meter works in a relatively stable working state, the periodicity of the working voltage of the electric energy meter is relatively stable; while in the case of a fault of the electric energy meter, the amplitude or the duration of the voltage signal of the working voltage of the electric energy meter may deviate. Therefore, the duration of the voltage signal segment can be resampled to the average duration to facilitate the determination of the reliability of the electric energy meter.

[0036] Resampling includes upsampling and downsampling. For the target voltage signal segment with a duration different from the average duration among multiple voltage signal segments, the duration of the target voltage signal segment can be resampled to the average duration, including: when the duration of the target voltage signal segment is greater than the average duration, downsample the target voltage signal segment so that the duration of the downsampled target voltage signal segment is equal to the average duration; when the duration of the target voltage signal segment is less than the average duration, upsample the target voltage signal segment so that the duration of the upsampled target voltage signal segment is equal to the average duration.

[0037] In this way, by resampling the duration of the voltage signal segment to the average duration, it is convenient to analyze the shape of the voltage signal within the same duration, so as to better determine the reliability of the electric energy meter.

[0038] In one embodiment, the first difference degree value is determined in the following manner: , where H is the first difference degree value, M is the number of voltage signal segments, norm is the normalization processing function, is the duration of the i-th voltage signal segment, It is to take the absolute value.

[0039] Since the determined multiple voltage signal segments are the periodic segments in the voltage signal curve of the operating voltage of the watt-hour meter, if the difference in the durations of different voltage signal segments is large, it indicates that the stability of the period of the operating voltage of the watt-hour meter is low, and the probability of abnormalities in the components inside the watt-hour meter is higher. Comparing the durations of different voltage signal segments with the average duration respectively can enable the first degree of difference value to better characterize the degree of difference in duration between different voltage signal segments, thereby characterizing the degree of fluctuation of the period of the watt-hour meter.

[0040] In one embodiment, the second degree of difference value is determined in the following manner: , where E is the second degree of difference value, M is the number of voltage signal segments, norm is the normalization processing function, f is the sampling frequency of the voltage signal, is the duration of the i-th voltage signal segment, is the j-th voltage in the i-th voltage signal segment, is the average value of the voltages within the i-th voltage signal segment, It is to take the absolute value.

[0041] The greater the difference between the voltages at different moments within the same voltage signal segment and the average voltage, the greater the degree of fluctuation of the operating voltage of the watt-hour meter at different moments within the same voltage signal segment. This degree of fluctuation of the operating voltage may accelerate the damage of the components inside the watt-hour meter, or this degree of fluctuation of the operating voltage may be caused by abnormalities in the components inside the watt-hour meter. Therefore, by comparing the voltages at different moments within the same voltage signal segment with the average voltage, it helps to better evaluate the state of the watt-hour meter.

[0042] In step S103, according to the DTW distance between adjacent voltage signal segments, a third degree of difference value is determined, and the average value of the first degree of difference value, the second degree of difference value, and the third degree of difference value is used as the target evaluation value.

[0043] The target evaluation value is used to characterize the degree of difference between different voltage signal segments. For example, the difference value of the voltage signals at the corresponding positions of two voltage signal segments can be determined, so as to analyze the degree of difference in the signal shape between the two voltage signal segments. By comparing the difference values of the voltage signals at the corresponding positions of multiple voltage signals, the degree of difference between multiple voltage signal segments can be reflected integrally. Therefore, according to the obtained target evaluation value, the degree of difference between different voltage signal segments can be better characterized.

[0044] In one embodiment, the third degree of difference value is determined in the following manner: , where G is the third degree of difference value, M is the number of voltage signal segments, N is the preset neighborhood radius, norm is the normalization function, is the DTW distance between the i-th voltage signal segment and the n-th other voltage signal segment within the neighborhood of the i-th voltage signal segment.

[0045] The DTW (Dynamic Time Warping) distance is a distance used to measure the difference between two time series. The DTW distance can be applied to fields such as speech recognition, gesture recognition, and bioinformatics.

[0046] The DTW distance between two time series is negatively correlated with the similarity between the two time series; the smaller the DTW distance between two time series, the higher the similarity between the two time series; conversely, the larger the DTW distance between two time series, the lower the similarity between the two time series.

[0047] By the DTW distance between adjacent voltage signal segments, the volatility of the working voltage of the electric energy meter can be reflected.

[0048] Since the first degree of difference value is used to characterize the difference in duration between different voltage signal segments, the second degree of difference value is used to characterize the difference in voltage at different moments within the same voltage signal segment among multiple voltage signal segments, and the third degree of difference value is determined according to the DTW distance between adjacent voltage signal segments among multiple voltage signal segments, taking the average value of the first degree of difference value, the second degree of difference value, and the third degree of difference value as the target evaluation value, the target evaluation value can evaluate the fluctuation of the working voltage of the electric energy meter from at least two aspects: the difference at different moments within the same voltage signal segment and the difference between different voltage signal segments.

[0049] In step S104, obtain the average time between failures of the electric energy meter in the historical time period, and obtain the reliability value of the electric energy meter according to the target evaluation value and the average time between failures, so as to output the status evaluation result of the electric energy meter using the reliability value.

[0050] Since the target evaluation value can better characterize the difference degree between different voltage signal segments, and when the reliability of the electric energy meter is at a relatively high level, for example, when the electric energy meter has 100% remaining service life, the voltage signals of the working voltage of the electric energy meter at different time periods are relatively close, and the obtained target evaluation value will be smaller. Therefore, through the target evaluation value and the average time between failures, the reliability value of the electric energy meter can be determined.

[0051] The reliability value can be used to characterize the time interval between the current moment and the predicted moment when the electricity meter will fail next time. For example, when the time interval between the current moment and the predicted moment when the electricity meter will fail next time is less than or equal to the second preset duration, it indicates that the electricity meter will fail in the near future or even be unable to continue to be used. To ensure the normal use of the equipment that provides the voltage signal by the electricity meter, the electricity meter can be replaced with a new one. Among them, the second preset duration can be set according to actual needs. For example, the second preset duration can be between 10 hours and 24 hours.

[0052] Through the method for evaluating the state of an electricity meter provided by the embodiments of the present application, a voltage signal curve of the electricity meter in a target time period is obtained, and the voltage signal curve is subjected to periodic detection to determine a voltage signal segment with periodicity in the voltage signal curve; according to the difference situation of the voltage signal segments and the average failure interval duration of the electricity meter in a historical time period, the reliability value of the electricity meter can be obtained, which can more conveniently realize the evaluation of the state of the electricity meter compared with obtaining the environmental load surface of the electricity meter and determining the reliability.

[0053] For a voltage signal segment with a duration equal to the average duration, according to the difference value of the voltage signals at the corresponding positions of different voltage signal segments, a target evaluation value is determined. The target evaluation value can better characterize the difference degree between different voltage signal segments, so as to obtain a more accurate reliability value of the electricity meter and better realize the evaluation of the state of the electricity meter.

[0054] In one embodiment, the determining the target evaluation value according to the difference value of the voltage signals at the corresponding positions of different voltage signal segments includes: determining a voltage signal segment combination from multiple voltage signal segments with a duration equal to the average duration, where the voltage signal segment combination includes two different voltage signal segments; determining the difference degree value corresponding to the voltage signal segment combination according to the difference value of the voltage signals at the corresponding positions of the two voltage signal segments in the voltage signal segment combination; determining the target average value of different difference degree values corresponding to different voltage signal segment combinations, and determining the target evaluation value according to the target average value.

[0055] For example, when the number of different voltage signal segments is 10, if a voltage signal segment combination including two voltage signal segments is selected from the 10 voltage signal segments, 5×9 = 45 voltage signal segment combinations can be determined.

[0056] According to the difference value of the voltage signals at the corresponding positions of two voltage signal segments in the voltage signal segment combination, determine the difference degree value corresponding to the voltage signal segment combination. The difference degree between the two voltage signal segments in the voltage signal segment combination can be characterized by the difference degree value. For example, the difference degree value can be equal to the mean value of multiple difference values of the voltage signals at different corresponding positions. The difference value of the voltage signals at the corresponding positions of two voltage signal segments can be the absolute value of the difference between the voltage signals at the corresponding positions of the two voltage signal segments.

[0057] For example, taking the number of data points included in the voltage signal segment as 5, the voltage signal segment combination includes a first voltage signal segment and a second voltage signal segment. The data of each data point in the first voltage signal segment, that is, the voltage signals at different moments in the first voltage signal segment are A1, A2, A3, A4, and A5 respectively, and the voltage signals at different moments in the second voltage signal segment are B1, B2, B3, B4, and B5 respectively.

[0058] The difference values of the voltage signals at the corresponding positions of the first voltage signal segment and the second voltage signal segment are respectively 、 、 、 and respectively. The mean value of these multiple difference values can be used as the difference degree value corresponding to the voltage signal segment combination.

[0059] In this way, since the difference degree value can characterize the difference degree between the voltage signal segments in the voltage signal segment combination, determine the target average value of different difference degree values corresponding to different voltage signal segment combinations. The target average value can reflect the difference degree between the periodic voltage signal segments in the target time period. The target evaluation value determined according to the target average value can reflect the abnormality degree of the electric energy meter in the target time period, providing a reference for determining the reliability of the electric energy meter.

[0060] The following takes an exemplary calculation formula as an example to illustrate the obtaining process of the target average value of different difference degree values corresponding to different voltage signal segment combinations in the embodiments of the present application:

[0061] , where G is the target average value, M is the number of voltage signal segments, i is a positive integer less than M; k is a positive integer less than or equal to M and greater than i; N is the number of voltage signals in the voltage signal segment, j is a positive integer less than or equal to N, norm is a normalization processing function, is the magnitude of the jth voltage signal in the ith voltage signal segment, is the magnitude of the j-th voltage signal in the k-th voltage signal segment, and the normalization function can be, for example, a logarithmic function.

[0062] In one embodiment, determining the target evaluation value according to the target average value includes: determining a first fluctuation value of the durations of multiple voltage signal segments before resampling; taking the average value of the first fluctuation value and the target average value as the target evaluation value.

[0063] The durations of multiple voltage signal segments before resampling may be different. The first fluctuation value of the durations of multiple voltage signal segments before resampling can characterize the fluctuation degree of the durations of multiple voltage signal segments before resampling, and the first fluctuation value can be determined according to the variance, standard deviation, range, etc. of the durations of multiple voltage signal segments before resampling.

[0064] In this way, taking the average value of the first fluctuation value and the target average value as the target evaluation value, since the first fluctuation value can characterize the fluctuation degree of the durations of multiple voltage signal segments before resampling, the target evaluation value can provide a better reference for estimating the reliability of the electric energy meter.

[0065] In one embodiment, determining the target evaluation value according to the target average value includes: determining the average value of the voltage signals of the voltage signal segments before resampling; determining a second fluctuation value between the different average values of the voltage signals corresponding to different voltage signals, where the second fluctuation value is used to characterize the difference degree between the different average values of the voltage signals; taking the average value of the second fluctuation value and the target average value as the target evaluation value.

[0066] By determining the average value of the voltage signals of the voltage signal segments before resampling and determining the second fluctuation value between the different average values of the voltage signals corresponding to different voltage signals, the second fluctuation value can characterize the fluctuation degree of the average values of the voltage signals of different voltage signals within the target time period; where the second fluctuation value can be determined according to the variance, standard deviation, range, etc. of the different average values of the voltage signals corresponding to different voltage signals.

[0067] In this way, since the second fluctuation value can characterize the fluctuation degree of the average values of the voltage signals of different voltage signals within the target time period, taking the average value of the second fluctuation value and the target average value as the target evaluation value, the target evaluation value can better provide a reference for estimating the reliability of the electric energy meter.

[0068] In one embodiment, obtaining a reliability value of the electricity meter according to the target evaluation value and the mean time between failures includes: performing an exponential operation on the square of the target evaluation value using an exponential function with the natural constant as the base to obtain an exponential operation value; multiplying the reciprocal of the exponential operation value by the mean time between failures to obtain a reliability value; the reliability value is used to represent the time interval between the current moment and the predicted moment when the electricity meter fails next time.

[0069] The target evaluation value can represent the probability that the electricity meter has an abnormality. The higher the probability that the electricity meter has an abnormality at the current moment, the shorter the time interval between the current moment and the predicted moment when the electricity meter fails next time, and thus the lower the reliability of the electricity meter.

[0070] By performing an exponential operation on the average of the target evaluation value to obtain an exponential operation value, and multiplying the reciprocal of the exponential operation value by the mean time between failures to obtain a reliability value, it can not only achieve the normalization processing of the target evaluation value, but also represent the time interval between the current moment and the predicted moment when the electricity meter fails next time through the obtained reliability value.

[0071] In one embodiment, the mean time between failures of the electricity meter in a historical time period is obtained in the following manner: determining the running duration of the electricity meter in the historical time period, and determining the number of failures of the electricity meter during the running duration; taking the ratio of the running duration to the number of failures as the mean time between failures.

[0072] The mean time between failures (abbreviated as MTBF) is one of the important indicators for measuring the reliability of a product, and it represents the average time length that the product can work normally between two consecutive failures.

[0073] In this way, by determining the mean time between failures, it can provide a reference for determining the reliability of the electricity meter at the current moment.

[0074] In one embodiment, using the reliability value to output a status evaluation result of the electricity meter includes: when the reliability value represents that the time interval between the current moment and the predicted moment when the electricity meter fails next time is greater than or equal to a second preset duration, prompting that the status evaluation result of the electricity meter is good.

[0075] The second preset duration can be set according to actual needs; when the reliability value represents that the time interval between the current moment and the predicted moment when the electricity meter fails next time is greater than or equal to the second preset duration, it indicates that the time for the electricity meter to fail next time is relatively long, and it can be determined that the working state of the electricity meter is normal.

[0076] In one embodiment, the state evaluation result of the electricity meter is output by using the reliability value, including: when the reliability value indicates that the time interval between the current moment and the predicted moment of the next failure of the electricity meter is less than the second preset duration, a prompt message is output; the prompt message is at least used to prompt the predicted moment of the next failure of the electricity meter.

[0077] When the reliability value indicates that the time interval between the current moment and the predicted moment of the next failure of the electricity meter is less than the second preset duration, it means that the time interval for the electricity meter to the next failure is short. The replacement or repair plan of the electricity meter can be formulated in advance to ensure that the electricity meter in use is always in a high reliability by replacing it in advance; or, the preparation of materials required for maintenance can be carried out in advance to shorten the total duration required for subsequent maintenance of the electricity meter.

[0078] After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily conceive of other embodiments of the present application. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include the common general knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and embodiments are only regarded as exemplary.

[0079] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A method for state evaluation of an electric energy meter, characterized in that, Including: Obtain the voltage signal curve of the working voltage of the electric energy meter within the target time period, perform zero-crossing detection on the voltage signal curve to obtain multiple voltage zero positions, and use the segments where a preset number of consecutive voltage zero positions in time sequence are located as candidate signal segments; when the duration of the candidate signal segment is greater than or equal to the first preset duration, use the candidate signal segment as the voltage signal segment; When the duration of the candidate signal segment is less than the first preset duration, merge multiple adjacent candidate signal segments with a duration less than the first preset duration to obtain the voltage signal segment; Determine the first degree of difference value according to the difference degree of different voltage signal segments in duration, and determine the second degree of difference value according to the difference degree of voltages at different times within the same voltage signal segment; Determine the third degree of difference value according to the DTW distance between adjacent voltage signal segments, and use the average value of the first degree of difference value, the second degree of difference value, and the third degree of difference value as the target evaluation value; Obtain the average time between failures of the electric energy meter in the historical time period, and obtain the reliability value of the electric energy meter according to the target evaluation value and the average time between failures, so as to output the status evaluation result of the electric energy meter by using the reliability value; The reliability value is used to represent the time interval between the current moment and the predicted moment when the next failure of the electric energy meter occurs.

2. The state evaluation method for an electric energy meter according to claim 1, wherein The first degree of difference value is determined by the following method: , where H is the first degree of difference value, M is the number of voltage signal segments, norm is the normalization function, is the duration of the i-th voltage signal segment, is to take the absolute value.

3. The state evaluation method for an electric energy meter according to claim 1, characterized in that, The second degree of difference value is determined by the following method: , where E is the second difference degree value, M is the number of voltage signal segments, norm is the normalization function, f is the sampling frequency of the voltage signal, is the duration of the i-th voltage signal segment, is the j-th voltage in the i-th voltage signal segment, is the average value of the voltages within the i-th voltage signal segment, represents taking the absolute value.

4. The state evaluation method for an electric energy meter according to claim 1, characterized in that, Obtain the reliability value of the electric energy meter according to the target evaluation value and the average time between failures, including: Perform exponential operation on the square of the target evaluation value by using the exponential function with the natural constant as the base to obtain the exponential operation value; multiply the reciprocal of the exponential operation value by the average time between failures to obtain the reliability value.

5. The state evaluation method for an electric energy meter according to claim 1, characterized in that, The average time between failures of the electric energy meter in the historical time period is obtained by the following method: Determine the running duration of the electric energy meter within the historical time period, and determine the number of failures of the electric energy meter during the running duration; Use the ratio of the running duration to the number of failures as the average time between failures.

6. The state evaluation method for an electric energy meter according to claim 1, characterized in that, Output the status evaluation result of the electric energy meter by using the reliability value, including: When the reliability value represents that the time interval between the current moment and the predicted moment when the next failure of the electric energy meter occurs is greater than or equal to the second preset duration, prompt that the status evaluation result of the electric energy meter is good.

7. The state evaluation method for an electric energy meter according to claim 1, characterized in that, Output the status evaluation result of the electric energy meter by using the reliability value, including: When the reliability value represents that the time interval between the current moment and the predicted moment when the next failure of the electric energy meter occurs is less than the second preset duration, output a prompt message; the prompt message is at least used to prompt the predicted moment when the next failure of the electric energy meter occurs.

8. The state evaluation method for an electric energy meter according to claim 1, wherein The method further includes: For the target voltage signal segment with a duration different from the average duration among multiple voltage signal segments, the duration of the target voltage signal segment can be resampled to the average duration; the average duration is equal to the average value of the durations of all voltage signal segments.

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