A low-carbon and energy-saving intelligent electric energy meter acquisition method

Abstract

The application discloses a low-carbon and energy-saving intelligent electric energy meter acquisition method and relates to the technical field of electric energy data acquisition. The method comprises the following steps: obtaining a plurality of load current sampling values of a target electric energy meter in a historical period and determining a current fluctuation profile; extracting a steady-state operation section and a transient-state operation section according to the current fluctuation profile; acquiring voltage effective values and current effective values in the steady-state operation section according to a first acquisition interval; generating a dynamic acquisition window according to a starting time and an ending time in the transient-state operation section, and acquiring voltage instantaneous values and current instantaneous values in the window according to a second acquisition interval; and generating electric energy cumulative increments according to the effective values and the instantaneous values. The method realizes section division through identification of current fluctuation characteristics, respectively acquires steady-state power data and transient-state instantaneous waveform data in differentiated acquisition granularity, and can reduce the number of generated redundant sampling points on the premise of complete capture of power consumption information.

Description

Technical Field

[0001] This invention relates to the field of electrical energy data acquisition technology, specifically a low-carbon and energy-saving smart energy meter data acquisition method. Background Technology

[0002] In the data acquisition process of smart meters, traditional methods typically employ a fixed frequency to continuously sample the voltage and current of the meter. Regardless of the operating state of the downstream load, the acquisition system performs analog-to-digital conversion and data recording at the same cycle. Existing technologies include schemes that switch sampling frequencies by setting load thresholds; however, this approach relies on fixed threshold comparisons, making it difficult to accurately capture the structural characteristics of load fluctuations and limiting its ability to distinguish between transient spikes and phased transitions in operating conditions. Furthermore, when determining the acquisition time window for transient processes, if the window is opened solely based on the trigger moment of load abrupt changes, the leading and trailing edges of the transient event are easily truncated, resulting in incomplete waveforms within the acquisition window. Therefore, how to extract features characterizing the continuous nature of the operating state from the historical sequence of load current, and thereby fully preserve steady-state power information and transient change processes while reducing the overall amount of acquired data, has become a problem to be solved in this field. Summary of the Invention

[0003] This invention provides a low-carbon and energy-saving smart energy meter data acquisition method. The purpose is to identify the current fluctuation profile by differential sign continuity analysis of the load current sampling sequence, thereby dividing the energy meter operation process into steady-state operation segment and transient operation segment. In different segments, sparse effective value acquisition and waveform dense acquisition within a dynamic window based on delay extension are used respectively, thereby reducing data redundancy during steady-state period and ensuring the integrity of energy increment calculation during transient process.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides a low-carbon and energy-saving smart energy meter data acquisition method for acquiring energy data from a target energy meter. By identifying load change characteristics, the acquisition strategy is adaptively adjusted to reduce energy consumption while ensuring metering accuracy.

[0005] This method acquires multiple load current sampling values ​​of the target energy meter within a historical time period and determines the current fluctuation profile of the target energy meter based on these values. The steady-state and transient operating sections of the target energy meter are extracted based on the current fluctuation profile. Within the steady-state operating section, the effective voltage and current values ​​of the target energy meter are collected at a first sampling interval. Within the transient operating section, a dynamic acquisition window is generated based on the start and end times of the transient operating section, and the instantaneous voltage and current values ​​of the target energy meter are collected at a second sampling interval within this window. The cumulative energy increment of the target energy meter within the historical time period is generated based on the effective voltage, effective current, instantaneous voltage, and instantaneous current values. By using the above method, the effective value is collected at a lower frequency in the steady-state section where the current fluctuation is gentle, which significantly reduces the number of samplings and the amount of data processing, thus achieving energy saving and consumption reduction. For the transient section where the current changes significantly, the instantaneous value is collected at a higher frequency through a dynamic acquisition window to fully capture the details of the power change in the transient process and avoid power metering errors caused by excessively large acquisition intervals.

[0006] As a technical solution of this invention, when determining the current fluctuation profile, multiple load current sample values ​​are arranged in chronological order of sampling time to obtain a current sampling sequence; a sliding difference operation is performed on the current sampling sequence to obtain a difference sequence; the sampling intervals corresponding to consecutive difference values ​​with the same sign in the difference sequence are marked as unidirectional change intervals; based on the start and end times of the marked multiple unidirectional change intervals and the extreme points of the load current sample values ​​within the intervals, a current fluctuation profile is generated. The current fluctuation profile extracted in this way can clearly reflect the changing trend and turning characteristics of the load current, providing a reliable basis for subsequent segmentation.

[0007] Preferably, the specific process for extracting steady-state and transient operating segments from the current fluctuation profile is as follows: The starting and ending load current values ​​of each unidirectional change interval are read from the current fluctuation profile, and the absolute difference between the starting and ending load current values ​​is calculated. When the time interval between any two adjacent unidirectional change intervals with an absolute difference less than a preset fluctuation threshold is less than a preset interval threshold, the two adjacent unidirectional change intervals and the sampling interval between them are merged into a steady-state operating segment. The sampling interval of each unidirectional change interval that is not merged into a steady-state operating segment is marked as a transient operating segment. This method can accurately distinguish between periods of stable load operation and periods of sudden load changes, making the switching of the acquisition strategy based on evidence and avoiding the loss of key information when using a steady-state acquisition method during load fluctuation transitions.

[0008] Furthermore, when collecting RMS voltage and current values ​​within the steady-state operating range, the duration of the steady-state operating range is obtained, and the first sampling quantity is determined based on the duration. Using the start time of the steady-state operating range as the sampling starting point and the first sampling interval as the sampling step size, the first sampling quantity of RMS voltage values ​​is sequentially collected within the steady-state operating range. Simultaneously, at the same sampling time for each voltage RMS value collection, the corresponding current RMS value is collected, and the voltage and current RMS values ​​collected at the same sampling time are paired and stored as steady-state sampling points. Accordingly, the sampling quantity within the steady-state range is adapted to the range length, ensuring sufficient sampling points within the steady-state range to reflect the average power level while avoiding over-collection.

[0009] In this process, the first sampling quantity is determined as follows: the duration is compared with a preset baseline duration, and a multiplication factor is determined based on the comparison result; the product of the preset baseline sampling quantity and the multiplication factor is used as the candidate sampling quantity; when the candidate sampling quantity is less than or equal to a preset upper limit value, the candidate sampling quantity is used as the first sampling quantity; when the candidate sampling quantity is greater than the upper limit value, the upper limit value is used as the first sampling quantity. Through the above constraints, the number of steady-state sampling points is dynamically adjusted within a reasonable range, balancing computational accuracy and acquisition energy consumption, and preventing excessive sampling due to excessively long segments.

[0010] As another technical solution of the present invention, when generating the dynamic acquisition window, the start time of the window is obtained by subtracting a preset pre-delay duration from the start time of the transient operating segment; the end time of the window is obtained by adding a preset post-delay duration to the end time of the transient operating segment; and the time period between the start time and the end time of the window is used as the dynamic acquisition window. By setting the pre-delay and post-delay, the boundary areas that may be affected by the transient process are included in the high-frequency acquisition range, which is beneficial to completely capture the changes in electrical quantities before and after the transient event and avoid incomplete instantaneous value acquisition caused by the positioning deviation of the transient interval boundary.

[0011] When acquiring instantaneous voltage and current values ​​within a dynamic acquisition window, the window duration is determined, and the second sampling quantity is calculated based on this duration. Using the start time of the dynamic acquisition window as the acquisition starting point and the second acquisition interval as the sampling step size, the second sampling quantity of instantaneous voltage values ​​is sequentially acquired within the dynamic acquisition window. Simultaneously, at the same sampling moment for each voltage instantaneous value acquisition, the corresponding instantaneous current value is acquired. The voltage and current instantaneous values ​​acquired at the same sampling moment are paired and stored as transient sampling points. The second sampling quantity is dynamically determined based on the window duration, ensuring that high-frequency acquisition is strictly limited to non-stationary regions. This maximizes the compression of high-frequency acquisition data while capturing transient energy information, thereby reducing overall power consumption.

[0012] Preferably, when determining the second sampling quantity, the window duration is divided by a preset unit duration to obtain the initial sampling number; the initial sampling number is rounded up to obtain an integer sampling number; when the integer sampling number is greater than a preset upper limit for the sampling number, the upper limit is used as the second sampling quantity; when the integer sampling number is less than or equal to the upper limit, the integer sampling number is used as the second sampling quantity. This ensures that the number of transient sampling points meets the accuracy requirements of energy integration calculation without causing excessive data volume due to an excessively long window, thus maintaining the energy efficiency control of the acquisition strategy.

[0013] In the stage of generating the cumulative energy increment, the steady-state energy increment within the steady-state operating range is calculated based on the effective values ​​of each voltage and the corresponding effective values ​​of the current within the steady-state operating range. The transient energy increment within the transient operating range is obtained by integrating the instantaneous values ​​of each voltage and the corresponding instantaneous values ​​of the current over time. The steady-state energy increment and the transient energy increment are then added together to obtain the cumulative energy increment. For the steady-state range, the effective value multiplication and accumulation method is used to calculate the energy, which requires less computation and meets the accuracy requirements. For the transient range, the instantaneous value integration method is used to reconstruct the actual power waveform, ensuring measurement accuracy.

[0014] Specifically, when calculating the steady-state energy increment, the effective voltage and current values ​​of each steady-state sampling point are sequentially read from multiple steady-state sampling points within the steady-state operating range, and the effective power value of each steady-state sampling point is calculated. The time difference between the sampling time of each steady-state sampling point and the adjacent previous sampling time is calculated to obtain the sampling interval duration of each steady-state sampling point. The effective power value of each steady-state sampling point is multiplied by the corresponding sampling interval duration and then summed to obtain the steady-state energy increment. This method utilizes the non-uniform distribution characteristics of steady-state sampling points over time to accurately account for the actual length of each sampling interval, avoiding calculation errors introduced by changes in the sampling interval.

[0015] The smart energy meter data acquisition method of the present invention utilizes the current fluctuation profile to automatically identify the steady-state and transient operating characteristics of the load. During periods of stable load, it acquires effective values ​​at low frequency to reduce power consumption, and only initiates high-frequency instantaneous value acquisition during transient periods of significant load changes to ensure that metering accuracy is not compromised. This enables low-carbon and energy-saving operation at the level of a single energy meter, effectively extending the service life of the equipment and reducing the energy consumption of the entire network data acquisition system.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: By performing a sliding differential operation on the current sampling sequence and marking consecutive difference values ​​with the same sign as unidirectional change intervals, the current fluctuation profile reflecting the monotonic change trend of the current can be extracted from the temporal evolution of the load current. Unidirectional change intervals essentially correspond to segments of continuous increase or decrease in load current. Separating these intervals from the original sampling data provides a clear representation of the dynamic behavior of the load state over different time periods. Based on this, using the relationship between the absolute difference between the start and end load currents of the unidirectional change intervals and a preset fluctuation threshold as a criterion, and combining this with the time interval between adjacent unidirectional change intervals, several consecutive unidirectional change intervals where the load current only fluctuates slightly over a long period, along with the transition intervals between them, can be integrated into a steady-state operating segment. The key to this approach is using the consistency of the differential sign direction to identify the continuity of current changes, rather than relying on a single threshold to rigidly divide instantaneous sampled values. This allows slow drifts and intermittent small fluctuations to be accurately classified as steady-state processes, avoiding the misclassification of stable operating segments as transient events due to improper threshold settings. Therefore, the boundary of the steady-state operating section is more consistent with the switching node of the actual load conditions, providing an objective basis for significantly reducing the sampling frequency in the steady state.

[0017] For unidirectional variation intervals not merged into the steady-state operating range, their sampling intervals are directly marked as transient operating ranges. Based on the start and end times of the transient range, pre-delay and post-delay are introduced to generate a dynamic acquisition window. This window expansion mechanism ensures that current precursor changes before the formal occurrence of a transient event and tail fluctuations during current recovery after the event are included in the acquisition range, overcoming the problem of easily missing transient edge waveforms when cutting windows only according to the event trigger time. Within the dynamic acquisition window, instantaneous voltage and current values ​​are synchronously acquired at shorter sampling intervals, enabling the acquisition of high-time-resolution instantaneous power waveforms during transient events. Outside the window, equally dense sampling operations are not performed. The effective value acquisition results of the steady-state range are combined with the instantaneous value acquisition results of the transient range to participate in the generation of the cumulative energy increment. The steady-state part is calculated by accumulating the sparsely sampled effective power values ​​with the corresponding sampling interval duration, while the transient part is calculated by integrating the densely sampled instantaneous power over time to calculate the transient energy increment. The sum of the two parts constitutes the complete energy increment for the entire historical period. Despite a significant reduction in the overall number of sampling points, the statistical representativeness of steady-state power calculation and the waveform integrity of transient increment calculation were maintained, achieving a balance between energy consumption and measurement accuracy. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of a low-carbon, energy-saving smart meter data collection method; Figure 2 This is a flowchart of the method for determining the number of samples in the steady-state operating section; Figure 3 This is a schematic diagram of the load current sampling values ​​and the steady-state and transient operating sections; Figure 4 These are sampling curves of the effective values ​​of voltage and current within the steady-state operating range; Figure 5 This is a schematic diagram of the instantaneous voltage and current values ​​within the dynamic acquisition window of the transient operation section; Figure 6 These are the curves showing the steady-state and transient electrical energy increments and cumulative increments; Figure 7 It is the steady-state sampling point power RMS value and steady-state energy increment curve. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] See Figure 1This invention provides a low-carbon, energy-saving smart energy meter data acquisition method for collecting energy data from a target energy meter. The method acquires multiple load current sampling values ​​of the target energy meter within a historical time period and determines the current fluctuation profile of the target energy meter based on these values. The steady-state and transient operating sections of the target energy meter are extracted based on the current fluctuation profile. Within the steady-state operating section, the effective voltage and current values ​​of the target energy meter are collected at a first acquisition interval. Within the transient operating section, a dynamic acquisition window is generated based on the start and end times of the transient operating section, and the instantaneous voltage and current values ​​of the target energy meter are collected at a second acquisition interval within the dynamic acquisition window. The accumulated energy increment of the target energy meter within the historical time period is generated based on the acquired effective voltage, effective current, instantaneous voltage, and instantaneous current values. By distinguishing between steady-state and transient operating sections and employing different acquisition strategies for each, this method ensures the integrity of the data required for calculating the accumulated energy increment while reducing unnecessary data acquisition, thereby reducing energy consumption in the acquisition and processing stages.

[0022] In practical implementation, multiple load current sampling values ​​of the target energy meter are acquired within a historical time period, with each load current sampling value corresponding to a sampling moment. The load current sampling value refers to the current value obtained by the target energy meter during operation, through its internal current transformer or shunt current sensing element, by real-time measurement of the electrical load circuit connected to the downstream of the energy meter; it is not the sustaining current required for the energy meter's own operation. The acquisition method is as follows: the analog-to-digital converter built into the energy meter periodically samples the analog current signal output by the sensing element and converts it into a digital quantity according to a preset sampling period. In this embodiment, the sampling period is set to 1 millisecond, that is, the instantaneous load current value is collected every 1 millisecond, thus forming a continuous load current sampling sequence. Multiple load current sampling values ​​are arranged in chronological order according to the sampling moment to form a current sampling sequence. Elements in the current sampling sequence are arranged in ascending order of time.

[0023] A sliding difference operation is performed on the current sampling sequence. The sliding difference operation works by starting from the second element of the current sampling sequence and calculating the difference between each element and the previous element sequentially. All differences are then arranged in the order of calculation to obtain the difference sequence. Let the current sampling sequence contain N load current sample values, and the difference sequence contain N-1 difference values. The p-th difference value is obtained by subtracting the p-th load current sample value from the (p+1)-th load current sample value in the current sampling sequence, where p is an integer greater than or equal to 1 and less than or equal to N-1.

[0024] The sampling intervals corresponding to consecutive difference values ​​with the same sign in the difference sequence are marked as intervals of simultaneous change in the same direction. Consecutive difference values ​​with the same sign refer to adjacent difference values ​​in the difference sequence that both have positive or both have negative signs. The sampling intervals corresponding to consecutive positive difference values ​​are marked as one interval of simultaneous change in the same direction, and the sampling intervals corresponding to consecutive negative difference values ​​are marked as another interval of simultaneous change in the same direction. The sampling intervals corresponding to consecutive positive difference values ​​cover the sampling time range corresponding to all load current sampling values ​​that generated these difference values ​​in the current sampling sequence. The coverage method for the sampling intervals corresponding to consecutive negative difference values ​​is similar.

[0025] A current fluctuation profile is generated based on the start and end times of multiple marked unidirectional change intervals and the extreme points of the load current sample values ​​within each interval. The start and end times of each unidirectional change interval are the sampling times of the first and last load current sample values ​​within that interval, respectively. The extreme points of the load current sample values ​​within the interval include: if the unidirectional change interval is marked with continuous positive differential values, the extreme points are the minimum and maximum values ​​of the load current sample values ​​within that interval, with the minimum value corresponding to the start time and the maximum value corresponding to the end time; if the unidirectional change interval is marked with continuous negative differential values, the extreme points are the maximum and minimum values ​​of the load current sample values ​​within that interval, with the maximum value corresponding to the start time and the minimum value corresponding to the end time. The start and end times of each unidirectional change interval and the times of the extreme points are combined with the current value information to form the current fluctuation profile.

[0026] In some embodiments, the starting and ending load current values ​​for each unidirectional change interval are read from the current fluctuation profile. The starting load current value is the sampled load current value at the beginning of the unidirectional change interval, and the ending load current value is the sampled load current value at the end of the unidirectional change interval. The absolute difference between the starting and ending load current values ​​is calculated using the following formula: in, Indicates the initial load current value. Indicates the termination load current value. This represents the absolute difference.

[0027] The absolute difference calculated for each unidirectional change interval is compared with a preset fluctuation threshold. The preset fluctuation threshold is a pre-defined threshold for the magnitude of current change, used to distinguish whether current fluctuations are stable. The preset fluctuation threshold is set based on statistical analysis of the power supply network and load type of the target energy meter. For example, for residential users, whose daily load current fluctuations are usually small, the threshold can be set to 0.5 amps; while for industrial users, whose loads may exhibit regular small fluctuations, the threshold can be set to 2 amps. The size of this threshold directly affects the division between steady-state and transient operating sections. If the threshold is set too small, normal small fluctuations in load current will be incorrectly identified as transient events, causing frequent interruptions to the steady-state section, thus increasing the number of unnecessary instantaneous value collections and violating the initial goal of energy saving. Conversely, if the threshold is set too large, real, small-amplitude transient changes will be ignored. When the absolute difference of the unidirectional change intervals is less than the preset fluctuation threshold, the unidirectional change interval is identified as a low-fluctuation interval.

[0028] In all low-fluctuation intervals, the time interval between any two temporally adjacent low-fluctuation intervals is examined. The time interval between two adjacent low-fluctuation intervals is the time difference between the end time of the previous low-fluctuation interval and the start time of the next low-fluctuation interval. If the time difference between the end time of the previous low-fluctuation interval and the start time of the next low-fluctuation interval is less than a preset interval threshold, the two adjacent low-fluctuation intervals and the sampling interval between them are merged to obtain a steady-state operating segment. The preset interval threshold is a pre-set time length threshold used to define whether the short time interval between two low-fluctuation intervals can be merged. The setting of the preset interval threshold mainly depends on the shortest transition time required for the load to switch between two stable operating states. For example, the power switching transition time of common household appliances such as air conditioner compressors is usually on the order of hundreds of milliseconds. In this embodiment, the threshold can be set to 500 milliseconds. If the threshold is set too low, two low-fluctuation intervals that are close in time will not be able to be merged, causing what was originally a continuous steady-state process to be divided into multiple fragmented steady-state segments. This increases the complexity of segmentation and may lead to a data acquisition process being initiated in each fragmented segment, thus increasing system overhead. If the threshold is set too high, two independent steady-state processes that are separated by a long time and have actually completed load switching will be incorrectly merged together. This results in the merged "steady-state operating segment" containing the transient process of load switching, leading to the loss of critical transient energy information when using low-frequency RMS data acquisition in that segment.

[0029] Each sampling interval containing a unidirectional change interval that is not merged into the steady-state operating range is marked as a transient operating range. Unidirectional change intervals not merged into the steady-state operating range include: unidirectional change intervals with an absolute difference greater than or equal to a preset fluctuation threshold, and unidirectional change intervals with an absolute difference less than the preset fluctuation threshold but a time interval with an adjacent low-fluctuation interval not less than a preset interval threshold. The preset fluctuation threshold used for this judgment is the same parameter as the threshold used to identify low-fluctuation intervals. Its setting is also based on statistical analysis of the load characteristics connected to the target energy meter, aiming to quantify and distinguish between stable fluctuations and significant changes in load current. The magnitude of this threshold has the same impact on the results as in point 2. When the absolute difference of a unidirectional change interval is greater than or equal to this threshold, it indicates that the load current in that interval has undergone a significant change beyond the normal range, and is therefore identified as part of a transient process. This threshold determines which magnitudes of current changes are considered transient events requiring close monitoring and precise measurement.

[0030] See Figure 3 In the graph, the horizontal axis represents time in seconds, and the vertical axis represents the sampled load current in amperes. The solid black line curve represents the sampled load current values ​​collected by the target energy meter during the historical time period, with values ​​fluctuating roughly between 5 and 12 amperes. The points marked with red triangles on the curve are the extreme points of the load current.

[0031] Based on the changing trend and extreme points of the load current sampling values, the time axis in the figure is divided into several intervals of change in the same direction, and further distinguished into steady-state operation segments and transient operation segments. The green shaded area represents the steady-state operation segment, and the red shaded area represents the transient operation segment.

[0032] As can be observed from the figure, the steady-state operating ranges are from 0 to approximately 3 seconds, 4 to 7 seconds, and 8 to 10 seconds. During these ranges, the load current remains relatively stable with small fluctuations, and the curves are smooth and show little change, consistent with the definition of a low-fluctuation range in this embodiment. The red shaded areas correspond to the transient operating ranges of approximately 3 to 4 seconds and 7 to 8 seconds. During these periods, the load current exhibits significant fluctuations and rapid changes, with concentrated extreme points, and the waveform shows oscillations, reflecting transient characteristics.

[0033] The locations of the extreme points and their corresponding load current values ​​are relatively concentrated in the transient region, showing the process of rapid current change; while in the steady-state region, there are fewer extreme points, and the load current value is close to the constant 10 amperes.

[0034] In specific implementation, please refer to Figure 2 This determines the duration of the steady-state operating segment. The duration is the time interval between the start and end times of the steady-state operating segment.

[0035] The method for determining the first sampling quantity based on duration is as follows: the duration of the steady-state operating segment is compared with a preset reference duration, and the multiplier is determined based on the comparison result. The preset reference duration is a pre-defined time length value. The comparison result refers to the multiple relationship between the duration being greater than the preset reference duration or the degree relationship between the duration being less than or equal to the preset reference duration.

[0036] In some embodiments, the duration is divided by a preset baseline duration to obtain the duration ratio. The multiplier is determined based on the numerical range of the duration ratio. The correspondence between the duration ratio and the multiplier adopts a piecewise mapping method: when the duration ratio is greater than 0 and less than or equal to 1, the multiplier is 0.8; when the duration ratio is greater than 1 and less than or equal to 3, the multiplier is 1.0; when the duration ratio is greater than 3 and less than or equal to 8, the multiplier is 1.5; and when the duration ratio is greater than 8, the multiplier is 2.0. In the above piecewise mapping relationship, a larger duration ratio indicates a longer steady-state operating segment, corresponding to the allocation of a larger multiplier to obtain more sampling points to reflect the overall steady-state characteristics; when the duration ratio is less than or equal to 1, the duration is shorter, and a multiplier of 0.8 is used to appropriately reduce the number of sampling points to reduce acquisition energy consumption. The specific value of the multiplier is set according to the statistical characteristics of the duration distribution of the steady-state operating segment, which can achieve a balance between sampling integrity and acquisition energy consumption.

[0037] The preset baseline sampling number is multiplied by the scaling factor, and the product is used as the candidate sampling number. The preset baseline sampling number is a pre-defined positive integer, representing the number of sampling points expected to be collected under typical steady-state operating conditions. The formula for calculating the candidate sampling number is: in, Indicates the number of candidate samples. This indicates the preset number of baseline samples. This represents the multiplier.

[0038] The candidate sample size is compared with a preset upper limit. The preset upper limit is a pre-defined positive integer used to limit the maximum number of sampling points in a single steady-state operation segment, preventing excessive data collection due to prolonged duration. When the candidate sample size is less than or equal to the preset upper limit, it is used as the first sample size. When the candidate sample size is greater than the preset upper limit, it is used as the first sample size.

[0039] Starting from the beginning of the steady-state operating segment, and using the first sampling interval as the sampling step size, the first number of voltage RMS values ​​are sequentially collected within the steady-state operating segment. The first sampling interval is calculated based on the duration of the steady-state operating segment and the first number of samples. The calculation method is to divide the duration by the first number of samples minus one, ensuring that the sampling points are evenly distributed along the time axis. At the same sampling moment for each voltage RMS value acquisition, the corresponding current RMS value is simultaneously acquired. The voltage and current RMS values ​​acquired at the same sampling moment are paired and stored as a single steady-state sampling point. Each steady-state sampling point contains sampling moment information, the voltage RMS value, and the current RMS value.

[0040] See Figure 4 In the graph, the horizontal axis represents time in seconds, the left side of the vertical axis represents the RMS voltage in volts, and the right side represents the RMS current in amperes. The solid blue line represents the RMS voltage, and the dashed red line represents the RMS current. The overall fluctuation range of the RMS voltage is approximately between 219.5 volts and 220.75 volts, with relatively small and stable variations. The RMS current fluctuation range is approximately between 9.85 amps and 10.10 amps, exhibiting subtle fluctuations. Both the RMS voltage and RMS current show high-frequency, small-amplitude fluctuations without significant abrupt changes or large upward or downward trends, indicating that the target electricity meter was operating in a steady-state state during this historical period.

[0041] In practice, the start and end times of the marked transient operating segments are acquired. Pre-set pre-delay and post-delay durations are read. The preset pre-delay duration is set to 20 milliseconds, based on the fact that the initial change process of a typical transient event unfolds within a few to tens of milliseconds. Extending the delay forward by 20 milliseconds ensures that the steady-state baseline information before the transient occurs is included in the dynamic acquisition window, allowing the dynamic acquisition window to fully cover the initial characteristics of the transient. The preset post-delay duration is set to 40 milliseconds, based on the fact that the decay process of transient oscillations generally lasts for 1 to 2 power frequency cycles, with each power frequency cycle corresponding to 20 milliseconds. Extending the delay backward by 40 milliseconds ensures that the main stage of oscillation decay to a stable state is included in the dynamic acquisition window.

[0042] The start time of the dynamic acquisition window is obtained by subtracting the preset pre-delay duration from the start time of the transient operation segment. The end time of the dynamic acquisition window is obtained by adding the preset post-delay duration to the end time of the transient operation segment. The time period between the start time and the end time of the window is defined as the dynamic acquisition window.

[0043] To obtain the duration of the dynamic acquisition window, the method is to subtract the start time of the dynamic acquisition window from the end time of the dynamic acquisition window.

[0044] The second sampling number is determined based on the duration of the dynamic acquisition window. The process involves dividing the duration of the dynamic acquisition window by a preset unit duration to obtain the initial sampling number. The preset unit duration is set to 1 millisecond, based on a 1-millisecond time granularity. This ensures that the initial sampling number equals the duration of the dynamic acquisition window in milliseconds, facilitating rounding up. The initial sampling number is calculated using the following formula: in, Indicates the initial number of samples. This indicates the duration of the dynamic data acquisition window. This indicates the preset unit duration.

[0045] The initial sample number is rounded up to obtain an integer sample number. This integer sample number is then compared to a preset upper limit for the sample number. The preset upper limit is set to 5000, based on the fact that the acquisition device's buffer space and processing capacity can stably support a maximum of 5000 sample points in a single transient event acquisition. Exceeding this value will cause buffer overflow and increase data transmission latency; therefore, the upper limit is limited to 5000. When the integer sample number is greater than the preset upper limit, the value of the preset upper limit is used as the second sample number. When the integer sample number is less than or equal to the preset upper limit, the value of the integer sample number is used as the second sample number.

[0046] Starting from the beginning of the dynamic acquisition window, and using the second acquisition interval as the sampling step size, the second number of instantaneous voltage values ​​are sequentially acquired within the dynamic acquisition window. The second acquisition interval is a pre-set fixed sampling time interval, set to 0.2 milliseconds. The reason for setting the second acquisition interval to 0.2 milliseconds is that the voltage and current signals contain frequency components up to 5 kHz during transient processes, and a sampling rate of 5 kHz corresponds to a 0.2 millisecond sampling interval, which can meet the sampling requirements for complete reconstruction of the highest frequency components of interest. At the same sampling moment when each instantaneous voltage value is acquired, the corresponding instantaneous current value is simultaneously acquired. The instantaneous voltage and current values ​​acquired at the same sampling moment are paired to generate a transient sampling point, and the transient sampling point is associated with and stored with the corresponding sampling moment information.

[0047] See Figure 5 In the graph, the horizontal axis represents time in milliseconds, and the vertical axis represents voltage and current in volts and amperes, respectively. The solid blue line represents the instantaneous voltage value, and the dashed red line represents the instantaneous current value. The dynamic acquisition window is marked with a light yellow area, and the transient operation segment is marked with a gray area.

[0048] As shown in the figure, the transient operation segment corresponds to a time range of approximately 15 to 50 milliseconds. During this period, the instantaneous voltage value curve exhibits significant high-frequency oscillations with substantial amplitude fluctuations, and the instantaneous current value curve also displays complex changing characteristics, reflecting that the voltage and current signals during the transient process contain high-frequency components. According to this embodiment, the start and end times of the transient operation segment are the start and end times of the gray area, respectively. The dynamic acquisition window is formed by two light yellow acquisition window intervals: the start time of the transient segment is delayed by 20 milliseconds (pre-delay duration), and the end time is delayed by 40 milliseconds (post-delay duration). This ensures that the dynamic acquisition window covers the complete characteristics of the transient event.

[0049] The two light yellow areas on the left and right sides of the figure correspond to the time delays before and after the dynamic acquisition window, containing steady-state baseline information before and after the transient event. Both the instantaneous voltage and current values ​​exhibit relatively stable sinusoidal waveforms with stable amplitude and frequency, consistent with steady-state operation characteristics. High-frequency sampling is performed within the dynamic acquisition window using a second acquisition interval of 0.2 milliseconds to meet the analytical requirements of the highest frequency component (approximately 5kHz) in the transient signal, ensuring the data integrity for calculating transient energy increments.

[0050] In practical implementation, the paired and stored steady-state sampling points within the steady-state operating section are acquired. Each steady-state sampling point contains an RMS voltage value and an RMS current value, as well as the corresponding sampling time for both values. Based on the RMS voltage values ​​and corresponding RMS current values ​​within the steady-state operating section, the steady-state energy increment within the section is calculated. The paired and stored transient sampling points within the transient operating section are also acquired. Each transient sampling point contains an instantaneous voltage value and an instantaneous current value, as well as the corresponding sampling time for both.

[0051] Based on the instantaneous voltage and current values ​​within the transient operating segment, time is integrated to obtain the transient energy increment within the transient operating segment. The time integration process involves multiplying the instantaneous voltage and current values ​​at each transient sampling point within the transient operating segment to obtain the instantaneous power value at each sampling point. Using the sampling time of each transient sampling point as the time node, a numerical integration method is used to integrate the instantaneous power value sequence, with the integration interval extending from the start to the end of the transient operating segment. The numerical integration method employs the trapezoidal integration rule; the integral between two adjacent transient sampling points is the average of the instantaneous power values ​​of the two adjacent sampling points multiplied by the time difference between them. The integrals between all adjacent transient sampling points are accumulated to obtain the transient energy increment.

[0052] In some embodiments, the formula for calculating the transient energy increment is: in, Indicates the transient increase in electrical energy. This indicates the total number of transient sampling points within the transient operating section. This represents the instantaneous power value at the q-th transient sampling point. This represents the instantaneous power value at the (q+1)th transient sampling point. This represents the time difference between the sampling time of the q-th transient sampling point and the sampling time of the (q+1)-th transient sampling point. The instantaneous power value at the q-th transient sampling point. The instantaneous power value at the q-th transient sampling point is obtained by multiplying the instantaneous voltage value at the q-th transient sampling point by the instantaneous current value at the q-th transient sampling point. It is obtained by multiplying the instantaneous voltage value at the (q+1)th transient sampling point by the instantaneous current value at the (q+1)th transient sampling point.

[0053] Adding the steady-state energy increment to the transient energy increment yields the cumulative energy increment of the target energy meter over the historical period. The expression for calculating the cumulative energy increment is as follows: ,in Indicates the cumulative increase in electrical energy. This represents the steady-state increase in electrical energy.

[0054] See Figure 6 In the graph, the horizontal axis represents time in seconds, and the vertical axis represents electrical energy in joules. The graph contains three curves, corresponding to the steady-state electrical energy increment (solid green line), the transient electrical energy increment (dashed blue line), and the cumulative electrical energy increment (dotted red line).

[0055] The steady-state energy increment curve shows a linear upward trend in the time interval from 0 to about 70 seconds, indicating that the steady-state energy increment calculated by the paired sampling points of the effective voltage and effective current values ​​continues to increase in this steady-state operating section. At about 70 seconds, the curve shows a plateau phase, and the energy increment remains constant at about 150,000 joules, reflecting the end of the steady-state operating section sampling or the steady-state power remains unchanged.

[0056] The transient energy increment curve remains essentially zero between 0 and 70 seconds, indicating that there are no significant transient sampling points or transient energy contributions within the transient operation segment. From approximately 70 seconds onwards, the transient energy increment begins to rise, exhibiting a linear growth trend. This indicates that the transient energy increment obtained by integrating the product of the instantaneous voltage and instantaneous current values ​​within the dynamic acquisition window corresponding to the transient operation segment gradually accumulates, reflecting the energy change process of the transient event.

[0057] The cumulative energy increment curve shows an overall increasing trend, and it almost overlaps with the steady-state energy increment curve in the time interval from 0 to 70 seconds, indicating that the cumulative energy increment in this stage is mainly contributed by the steady-state energy increment. After 70 seconds, the cumulative energy increment curve is higher than the steady-state energy increment plateau value, and the slope is close to the growth trend of the transient energy increment curve, indicating that the transient energy increment begins to make a significant contribution to the total energy. The two are superimposed to form the overall change in the cumulative energy increment.

[0058] In practice, from the paired and stored set of steady-state sampling points, the effective voltage and current values ​​of each steady-state sampling point are read sequentially in ascending order of sampling time. The read effective voltage value is denoted as... The effective value of the current is denoted as ,in Indicates the sequential numbering of the steady-state sampling points. Let be a positive integer starting from 1, and let be the total number of steady-state sampling points. For each steady-state sampling point, the effective power value is calculated. The effective power value is obtained by multiplying the effective voltage value and the effective current value at the corresponding steady-state sampling point, as shown in the formula below. ,in Indicates the first The effective power value of each steady-state sampling point.

[0059] For each steady-state sampling point, obtain the sampling time of that point. For sequentially numbered... For steady-state sampling points greater than or equal to 2, the th The sampling time of the steady-state sampling point minus the first The sampling time of the nth steady-state sampling point, and the time difference obtained therefrom, are used as the nth steady-state sampling point. The sampling interval duration corresponding to each steady-state sampling point is denoted as . For sequential numbering The first steady-state sampling point with a value equal to 1 has no adjacent preceding steady-state sampling point. The sampling interval of the first steady-state sampling point is... Set to zero.

[0060] The steady-state power increment is obtained by multiplying the effective power value at each steady-state sampling point by the corresponding sampling interval duration and summing all the products. The formula for calculating the steady-state power increment is: in, Represents the steady-state increase in electrical energy. This represents the total number of steady-state sampling points. Indicates the first The effective power value at each steady-state sampling point Indicates the first The sampling interval time corresponding to each steady-state sampling point. Through the above accumulation process, the steady-state electrical energy increment within the steady-state operating range is obtained.

[0061] See Figure 7 In the graph, the horizontal axis represents time in seconds, ranging from 0 to 100 seconds. The left vertical axis represents the effective power value at the steady-state sampling point, in watts (W), ranging from approximately 2170W to 2230W; the right vertical axis represents the steady-state energy increment, in joules (J), ranging from 0 to approximately 220,000J. The orange curve represents the effective power value at the steady-state sampling point, which shows slight fluctuations on the time axis. The overall power value fluctuation range remains between approximately 2170W and 2230W, indicating that the collected power data has some random fluctuations within the steady-state operating range, but is generally stable without a significant trend. The purple curve represents the steady-state energy increment, which shows a linear increasing trend over time, indicating a gradual increase in accumulated energy.

[0062] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A low-carbon, energy-saving smart energy meter data collection method, characterized in that, The method is used to collect energy data from a target energy meter; the method includes: The target energy meter is obtained by acquiring multiple load current sampling values ​​within a historical period, and the current fluctuation profile of the target energy meter is determined based on the multiple load current sampling values. Based on the current fluctuation profile, the steady-state operating section and transient operating section of the target energy meter are extracted; within the steady-state operating section, the effective voltage value and effective current value of the target energy meter are collected according to the first acquisition interval; Within the transient operation segment, a dynamic acquisition window is generated based on the start and end times of the transient operation segment, and the instantaneous voltage and current values ​​of the target energy meter are acquired within the dynamic acquisition window according to the second acquisition interval. The cumulative energy increment of the target energy meter during the historical period is generated based on the effective voltage value, the effective current value, the instantaneous voltage value, and the instantaneous current value, including: The steady-state energy increment within the steady-state operating section is calculated based on the effective values ​​of each voltage and the corresponding effective values ​​of the current within that section. The formula for calculating the steady-state energy increment is as follows: Represents the steady-state increase in electrical energy. This represents the total number of steady-state sampling points. Indicates the first The effective power value at each steady-state sampling point Indicates the first The sampling interval duration corresponding to each steady-state sampling point; The transient energy increment within the transient operating section is obtained by integrating the instantaneous voltage and corresponding instantaneous current values ​​over time. The formula for calculating the transient energy increment is as follows: Indicates the transient increase in electrical energy. This indicates the total number of transient sampling points within the transient operating section. This represents the instantaneous power value at the q-th transient sampling point. This represents the instantaneous power value at the (q+1)th transient sampling point. This represents the time difference between the sampling time of the q-th transient sampling point and the sampling time of the (q+1)-th transient sampling point; The cumulative energy increment is obtained by adding the steady-state energy increment to the transient energy increment.

2. The low-carbon and energy-saving smart energy meter data collection method according to claim 1, characterized in that, Determining the current fluctuation profile of the target energy meter based on multiple load current sampling values ​​includes: The load current sample values ​​are arranged in chronological order of sampling time to obtain a current sampling sequence; Perform a sliding difference operation on the current sampling sequence to obtain a difference sequence; The sampling intervals corresponding to consecutive difference values ​​with the same sign in the difference sequence are marked as intervals of change in the same direction; The current fluctuation profile is generated based on the start and end times of the marked multiple unidirectional change intervals and the extreme points of the load current sampling values ​​within the intervals.

3. The low-carbon and energy-saving smart energy meter data collection method according to claim 2, characterized in that, Extracting the steady-state and transient operating sections of the target energy meter based on the current fluctuation profile includes: Read the starting load current value and ending load current value of each same direction change interval from the current fluctuation profile, and calculate the absolute difference between the starting load current value and the ending load current value. When the time interval between any two adjacent same-direction change intervals in the same-direction change interval where the absolute difference is less than the preset fluctuation threshold is less than the preset interval threshold, the two adjacent same-direction change intervals and the sampling interval between them are merged into the steady-state operation segment. The sampling interval containing each unidirectional change interval that was not merged into the steady-state operating segment is marked as the transient operating segment.

4. The low-carbon and energy-saving smart energy meter data collection method according to claim 1, characterized in that, Within the steady-state operating range, the effective voltage and effective current values ​​of the target energy meter are collected at the first acquisition interval, including: The duration of the steady-state operating segment is obtained, and the first sampling quantity is determined based on the duration. Taking the start time of the steady-state operation section as the starting point of the data collection, and taking the first data collection interval as the sampling step size, the first number of voltage RMS values ​​are collected sequentially within the steady-state operation section. At the same sampling moment when the voltage RMS value is collected each time, the corresponding current RMS value is collected synchronously, and the voltage RMS value and current RMS value collected at the same sampling moment are paired and stored as steady-state sampling points.

5. The low-carbon and energy-saving smart energy meter data collection method according to claim 4, characterized in that, Determining the first sampling quantity based on the duration includes: The duration is compared with a preset baseline duration, and the multiplier is determined based on the comparison result. The product of the preset baseline sampling number and the magnification coefficient is used as the candidate sampling number; When the number of candidate samples is less than or equal to a preset upper limit, the number of candidate samples is taken as the first sampling number; When the number of candidate samples is greater than the upper limit value, the upper limit value is used as the first sampling number.

6. The low-carbon and energy-saving smart energy meter data collection method according to claim 1, characterized in that, Generating a dynamic acquisition window based on the start and end times of the transient operation segment includes: The window start time is obtained by subtracting the preset pre-delay duration from the start time of the transient operation segment. The window end time is obtained by adding a preset post-delay duration to the end time of the transient operation segment; The time period between the start time and the end time of the window is used as the dynamic acquisition window.

7. The low-carbon and energy-saving smart energy meter data collection method according to claim 6, characterized in that, The instantaneous voltage and instantaneous current values ​​of the target energy meter are collected at the second acquisition interval within the dynamic acquisition window, including: Obtain the window duration of the dynamic acquisition window, and determine the second sampling quantity based on the window duration; Taking the start time of the dynamic acquisition window as the acquisition starting point and the second acquisition interval as the sampling step size, the instantaneous voltage values ​​of the second sampling number are sequentially acquired within the dynamic acquisition window; At the same sampling moment when the instantaneous voltage value is collected each time, the corresponding instantaneous current value is collected simultaneously, and the instantaneous voltage value and instantaneous current value collected at the same sampling moment are paired and stored as transient sampling points.

8. The low-carbon and energy-saving smart energy meter data collection method according to claim 7, characterized in that, Determining the second sampling quantity based on the duration of the window includes: Divide the duration of the window by the preset unit duration to obtain the initial number of samples; The initial sample number is rounded up to obtain the integer sample number; When the number of integer samples is greater than the preset upper limit of the number of samples, the upper limit of the number of samples is used as the second number of samples; When the number of integer samples is less than or equal to the upper limit of the number of samples, the number of integer samples is used as the second number of samples.

9. A low-carbon, energy-saving smart energy meter data collection method according to claim 8, characterized in that, The steady-state energy increment within the steady-state operating section is calculated based on the effective values ​​of each voltage and the corresponding effective values ​​of the current within the steady-state operating section, including: The effective voltage and effective current values ​​of each steady-state sampling point are read sequentially from multiple steady-state sampling points within the steady-state operating range, and the effective power value of each steady-state sampling point is calculated. Calculate the time difference between the sampling time of each steady-state sampling point and the adjacent previous sampling time to obtain the sampling interval duration of each steady-state sampling point; The steady-state power increment is obtained by multiplying the effective power value of each steady-state sampling point by the corresponding sampling interval duration and then summing the results.

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