Method and watt-hour meter

Abstract

To provide a set of data synchronized with timing as an offset value based upon a signal obtained from a watthour meter.SOLUTION: A method for finding a data set of an AC signal synchronized with timing when reaching an offset value and measured by a watthour meter, comprises the steps of: acquiring a set of sampling data obtained by sampling the AC signal measured by the watthour meter at sampling intervals of the watthour meter; calculating transition data which is shifted by a predetermined time from each sampling time point of the sampling data; and acquiring a transition dataset including the transition data, the predetermined time being based upon the timing when the AC signal reaches the offset value.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a method and a watt-hour meter, and more particularly to a method and a watt-hour meter for determining the timing at which a signal measured by the watt-hour meter reaches an offset value and for determining a data set of an AC signal synchronized with this timing. [Background technology]

[0002] Watt-hour meters are known that measure and display the amount of electricity used by electricity consumers such as ordinary households, buildings, factories, etc. Electronic watt-hour meters have an electronic circuit built into the device that measures the input current and input voltage, calculates the amount of electricity used, and outputs the result on a display panel.

[0003] Additionally, smart meters, which are electronic watt-hour meters equipped with communication functions, are being introduced. Smart meters measure the amount of electricity used and can transmit the measurement data to a remote location at specified intervals. By managing the transmitted measurement data, electric power companies no longer need to read the electricity usage meter every month. This means that they can measure the electricity usage status without entering the electricity consumer's building. This type of method is called non-intrusive, meaning that it does not require entering the building.

[0004] In order to measure the amount of power input, electronic watt-hour meters sample the input current and voltage to convert them into digital signals. However, due to factors such as fluctuations in the commercial power supply frequency, there can be a discrepancy between the timing at which the input current and voltage reach their offset values ​​and the timing at which the watt-hour meter samples them. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to obtain a set of data synchronized with the timing at which the input voltage or current becomes an offset value, based on a signal obtained from a watt-hour meter. [Means for solving the problem]

[0006] A characteristic feature of a method for achieving the above object is a method for obtaining a data set of an AC signal measured by a watthour meter, synchronized with the timing at which the AC signal becomes an offset value, the method comprising: a step of acquiring a set of sampling data obtained by sampling the AC signal measured by the watthour meter at the sampling interval of the watthour meter; a step of calculating transition data, wherein the transition data is shifted by a predetermined time from each sampling time of the sampling data; and a step of acquiring a transition data set including the transition data, wherein the predetermined time is based on the timing at which the AC signal becomes an offset value.

[0007] Furthermore, a characteristic configuration of an electricity meter for achieving the above-mentioned object is a electricity meter that obtains a data set of an AC signal measured by the electricity meter synchronized with the timing at which an offset value is reached, the electricity meter including at least one processor, and when executed by the at least one processor, causes the electricity meter to execute the steps of: acquiring a set of sampling data obtained by sampling the AC signal measured by the electricity meter at the sampling interval of the electricity meter; calculating transition data, where the transition data is shifted by a predetermined time from each sampling time of the sampling data; and acquiring a transition data set including the transition data, the predetermined time being based on the timing at which the AC signal reaches the offset value. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows a schematic configuration diagram of an energy meter according to an embodiment of the present disclosure. [Figure 2] 1 is a diagram showing time variations at multiple points in time of an AC signal measured by a watt-hour meter according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is an enlarged view of a portion of the time change in voltage measured by the watt-hour meter shown in FIG. 2. [Figure 4] FIG. 3 is an enlarged view of a portion of the time change in voltage measured by the watt-hour meter shown in FIG. 2. [Figure 5] 10 illustrates an example of processing executed in a control unit of a watt-hour meter according to an embodiment of the present disclosure. [Figure 6A] 1 illustrates an example set of trend data obtained for each first interval, according to one embodiment of the present disclosure. [Figure 6B] 1 illustrates a set of transition data obtained for each first interval and a set of additional data obtained for each second interval, according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiment of the present invention] First, the contents of an embodiment of the present invention will be listed and explained. One embodiment of the present invention has the following configuration.

[0010] [Configuration 1] The method for achieving the above object is characterized by the following features: A method for determining a data set of an AC signal measured by a watt-hour meter synchronized with a timing of an offset value, the method comprising: sampling the AC signal measured by the watt-hour meter at a sampling interval (T sample ) to obtain a set of sampling data (voltage value, current value), and sft , I sft ), wherein the transition data is calculated at each sampling time (t0 to t n ) by a predetermined time, and acquiring a transition data set including the transition data, wherein the predetermined time is based on a timing at which the AC signal reaches an offset value.

[0011] According to the above characteristic configuration, it is possible to obtain a set of data synchronized with the timing at which the input voltage or current becomes the offset value, based on the signal obtained from the watt-hour meter.

[0012] [Configuration 2] Another feature of the method according to the present invention is that The step of calculating the transition data further includes a step of extracting from the set of sampling data a set of sampling data included in the period between a first time when the AC signal centered on the selected one cycle passes through the offset value and a second time when the AC signal passes through the next offset value, sampling data immediately before the first time (T1), and sampling data immediately after the second time (T2).

[0013] [Configuration 3] Another feature of the method according to the present invention is that The step of calculating the transition data further includes a step of obtaining a first approximate line (L1) connecting two adjacent pieces of sampling data that are on an increasing trend across the first time from the set of extracted sampling data, a step of obtaining a second approximate line (L2) connecting two adjacent pieces of sampling data that are on an increasing trend across the second time from the set of extracted sampling data, and a step of obtaining a first time difference (Δt s ) and calculating the sampling time (t N ) and the second time (T2), which is the difference between the second time (T1) and the second time (T2), e ) and calculating the first time difference (Δt s ) and the second time difference (Δt e ) and the sampling interval (T sample ) and calculating an offset period from the first time to the second time.

[0014] [Configuration 4] Another feature of the method according to the present invention is that The step of calculating the transition data further includes calculating a first sampling time (t n ) sampling data (V n ) and the second sampling time (t n+1 ) sampling data (V n+1 ) and calculating, from the approximation formula, the transition data of the AC signal when shifted by the predetermined time from the first sampling time or the second sampling time.

[0015] [Configuration 5] Another feature of the method according to the present invention is that The transition data set includes transition data of a first interval based on an offset period from the first time to the second time, and further, in a predetermined offset period, the transition data set includes transition data of the first interval (T int1 ) shorter than the second interval (T int2 ), obtaining an additional dataset including the additional data, and including the additional dataset in the transition dataset.

[0016] According to the above characteristic configuration, it is possible to obtain a signal having a frequency higher than the sampling frequency of the watt-hour meter from the value of the signal obtained from the watt-hour meter without changing the sampling frequency of the watt-hour meter, thereby increasing the number of signal data.

[0017] [Configuration 6] Another feature of the method according to the present invention is that The step of calculating the additional data further includes a step of calculating an approximation formula for linearly approximating a line segment having both ends of the sampling data at a first sampling time and the sampling data at a second sampling time following the first sampling time in a set of sampling data included in the predetermined offset period between a first time when the AC signal passes through an offset value and a second time when the AC signal passes through a next offset value, and calculating from the approximation formula a predetermined second interval (T int2 ) for each additional data.

[0018] [Configuration 7] The characteristic configuration of the watt-hour meter to achieve the above purpose is as follows: A watthour meter that obtains a data set of an AC signal measured by the watthour meter, synchronized with the timing at which an offset value is reached, includes at least one processor, and when executed by the at least one processor, causes the watthour meter to execute the following steps: acquiring a set of sampling data obtained by sampling the AC signal measured by the watthour meter at the sampling interval of the watthour meter; calculating transition data, wherein the transition data is shifted by a predetermined time from each sampling time of the sampling data; and acquiring a transition data set including the transition data, wherein the predetermined time is based on the timing at which the AC signal reaches an offset value.

[0019] [Details of the embodiment of the present invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included in the present disclosure. In the following description, the same elements in the description of the drawings will be given the same reference numerals, and redundant explanations will not be repeated.

[0020] <Configuration of the electricity meter 10> FIG. 1 shows a schematic configuration diagram of a watt-hour meter 10 according to one embodiment of the present disclosure. The watt-hour meter 10 includes at least a control unit 12 that controls the operation of the watt-hour meter 10 and a terminal unit 14 that is connected to a load. The load may be a monitored device 30 that uses power that passes through the watt-hour meter 10. The watt-hour meter 10 measures the amount of power that passes through the watt-hour meter 10 and is supplied to the monitored device 30, and acquires usage information. The watt-hour meter 10 may be a single-phase or three-phase type.

[0021] The usage information may include instantaneous values ​​of the voltage input to the monitored device 30 at multiple points in time within a certain period of time. The usage information may also include instantaneous values ​​of the current flowing through the monitored device 30 at multiple points in time within a certain period of time.

[0022] The control unit 12 controls the operation of the watt-hour meter 10 and is composed of at least a processor (not shown), a memory (not shown), and a storage (not shown). These components of the control unit 12 are electrically connected to one another via a bus. The processor, memory, storage, and other components work together to function as the control unit 12. For example, the control unit 12 performs digital sampling processing of the current and voltage measured by the watt-hour meter 10 and acquires sets of sampling data of the current and voltage at multiple points in time. The control unit 12 also acquires sets of trend data from the sets of sampling data, which are obtained at timings based on offset values. Details of the trend data will be described later.

[0023] The processor loads the read program into memory and executes it. For example, the processor executes a series of instructions included in the program loaded into memory based on a signal acquired by the watt-hour meter 10.

[0024] Memory is a main storage device and is composed of storage devices such as ROM (Read Only Memory) and RAM (Random Access Memory). For example, memory provides a working area for a processor by temporarily storing programs and various data that the processor reads from storage (described later).

[0025] The storage is an auxiliary storage device that permanently stores programs and data. The storage is realized as a non-volatile storage device such as a hard disk drive or flash memory.

[0026] The watt-hour meter 10 may be a smart meter. In this case, as shown in FIG. 1 , the watt-hour meter 10 may further include a communication control unit 16 communicably connected to the watt-hour meter 10. The communication control unit 16 periodically transmits information (such as usage status data) to the electric power company. The communication control unit 16 may be configured separately from the watt-hour meter 10.

[0027] The monitored device 30 is composed of one or more electric devices or electronic devices, such as an air conditioner, a television, a personal computer (PC), a refrigerator, a microwave oven, or a combination thereof. The monitored device 30 may also be an IoT device.

[0028] FIG. 2 is a diagram showing temporal changes at multiple points in time of an AC signal, which is usage information measured by an energy meter 10 according to an embodiment of the present disclosure. In the following example, a case where the AC signal is a voltage will be described as an example, but the same applies to current. In this diagram, the vertical axis represents voltage, the horizontal axis represents time, and each point represents a voltage value (sampling data) measured at each point in time, showing a set of voltage values ​​(sampling data set) for approximately one cycle. In the example of FIG. 2, the temporal changes of the sampling data set form an approximately sinusoidal curve, but the sampling data set need only have periodicity and does not necessarily form a sinusoidal waveform.

[0029] In one example, the watt-hour meter 10 measures the voltage every second, with a measurement interval of 1 cycle / second. If the sampling frequency of the watt-hour meter 10 is 8 kHz, the sampling interval by the watt-hour meter 10 is 125 μS. In the example of Figure 2, when the commercial power frequency is 50 Hz, one cycle of the measured voltage is approximately 0.02 seconds due to the influence of the commercial power frequency, and approximately 160 sampling data are obtained per cycle.

[0030] Due to factors such as fluctuations in the commercial power frequency, a discrepancy may occur between the time at which the voltage waveform measured by the watt-hour meter 10 (time change in the set of sampled data) intersects with the offset value and the time of sampling by the watt-hour meter 10. Therefore, the commercial power cycle does not necessarily coincide with the measured voltage cycle. For example, when the commercial power frequency is 50 Hz, one cycle of the commercial power is 0.02 seconds, but one cycle of the measured voltage is not necessarily 0.02 seconds. According to the present disclosure, by calculating the offset cycle at which the time change in the set of measured sampled data intersects with the offset value, a new interval (first interval) is calculated based on the offset value for acquiring a desired number of data. Furthermore, the control unit 12 calculates a set of voltage value data based on the new interval (first interval) based on the offset cycle. Note that, although the description in this specification uses a commercial power system with a 50 Hz frequency as an example, the same applies to a 60 Hz system.

[0031] FIG. 3 is an enlarged view of a portion 300 of the voltage change over time measured by the watt-hour meter 10 shown in FIG. 2. FIG. 3 shows sampling data of voltage from sampling time t0, which is immediately before the first time T1 at which the measured voltage change over time intersects with the offset value, to subsequent sampling times t1 to t4. V0 is the voltage value at sampling time t0, and V1 is the voltage value at sampling time t1. In FIG. 3, two adjacent voltage values ​​are approximated by a linear line (e.g., line segment L1) with these two voltage values ​​as their ends. As shown in FIG. 3, the first time T1 at which the measured voltage change over time (linear line) becomes the offset value does not necessarily coincide with sampling times t0 and t1.

[0032] 4 is an enlarged view of a portion 400 of the voltage change over time measured by the watt-hour meter 10 shown in FIG. N-3 Then, the sampling time t immediately after the second time T2 at which the time change of the measured voltage intersects with the offset value N+1 The sampling data up to V N is the sampling time t N Voltage value at V N+1 is the sampling time t N+1 In FIG. 4, two adjacent voltage values ​​are approximated by a linear line (for example, line segment L2) with these two voltage values ​​as both ends. As shown in FIG. 4, the second time T2 at which the time change (linear line) of the measured voltage becomes an offset value is not necessarily the same as the sampling time t N , t N+1 does not necessarily correspond to

[0033] Fig. 5 shows an example of processing executed by control unit 12 of watt-hour meter 10 according to an embodiment of the present disclosure. Control unit 12 executes various processes shown in Fig. 5 according to program descriptions. Note that Fig. 5 describes an example of processing voltage values, but the processing shown in Fig. 5 can also be applied to current values ​​in the same manner.

[0034] Steps S502 to S508 involve calculating an offset period in which the measured voltage becomes an offset value, and acquiring a set of voltage transition data synchronized with timing based on the offset period based on the calculated offset period.

[0035] Steps S510 and S512 involve calculating a set of additional data that is further shifted in time by a fraction of the first interval from the shifted voltage transition data.

[0036] Steps S502 to S508 in FIG. 5 will now be described.

[0037] First, in step S502, the control unit 12 acquires a set of sampling data obtained when the voltage measured by the watt-hour meter 10 is sampled at the sampling interval of the watt-hour meter 10. As described above, the times (first time T1 and second time T2) at which the measured voltage becomes the offset value do not necessarily coincide with the sampling times. Therefore, in accordance with the processes of steps S504 to S508, the control unit 12 obtains transition data obtained at timings based on the offset value from the sampling data acquired in step S502.

[0038] In step S504, the control unit 12 selects any one period from the set of sampling data acquired in step S502 and extracts a set of sampling data for approximately one period centered around this period. The set of sampling data for approximately one period to be extracted includes (i) a set of sampling data included in the period between a first time T1, when the voltage centered on the selected period passes through a first offset value, and a second time T2, when the voltage passes through the next second offset value, (ii) sampling data immediately before the first time T1, and (iii) sampling data immediately after the second time T2. The first time T1 and the second time T2 will be described in detail below with reference to FIGS. 3 and 4.

[0039] As shown in FIG. 3, the first time T1 corresponds to the first intersection point CP1 at which a first approximate line L1 connecting two adjacent sampling data that are on an increasing trend across the first offset value intersects with the first offset value, among a set of sampling data obtained centered on one selected period.

[0040] 4, the second time T2 corresponds to the intersection point CP2 next to the intersection point CP1 where a second approximate line L2 connecting two adjacent sampling data that are on an increasing trend with the second offset value in between, among the set of sampling data obtained centered around the selected one period, intersects with the second offset value. Note that hereinafter, the first offset value and the second offset value may be collectively referred to as the offset value.

[0041] 5, in step S506, the control unit 12 calculates an offset period (T in FIG. 2) based on the times (first time T1 and second time T2) when the voltage measured by the watt-hour meter 10 intersects with the offset value. cycle ) is calculated. The offset value differs depending on the settings, situation, model, etc. of the watt-hour meter 10. When the offset value is zero volts, the offset period is the zero-cross period.

[0042] The offset period is the period from a first time T1, when the measured voltage passes a first offset value, to a second time T2, when the measured voltage passes a second offset value. The offset period does not have to coincide with the commercial power supply period. The offset period is calculated based on the set of sampling data extracted in step S504. More specifically, the offset period is calculated according to the following process.

[0043] First, the control unit 12 calculates a first time difference Δts, which is the difference between the first time T1 and the sampling time t1 immediately after the first time T1, from the set of sampling data extracted in step S504 (FIG. 3).

[0044] Specifically, the first time difference Δts is calculated by the following equation (1) based on the linearly approximated voltage waveform shown in FIG.

[0045]

number

[0046] where T sample is the sampling interval by the watt-hour meter 10, and Offset is the voltage offset value. V0 is the voltage value obtained at sampling time t0 immediately before the first time T1. V1 is the voltage value obtained at sampling time t1 immediately after the first time T1, i.e., the sampling data following V0.

[0047] Similarly, the sampling time t immediately before the second time T2N A second time difference Δte, which is the difference from the first time T1 to the second time T2, is calculated (FIG. 4). Based on the linearly approximated voltage waveform shown in FIG. 4, the second time difference Δte is calculated by the following equation (2).

[0048]

number

[0049] where V N is the sampling time t immediately before the second time T2 N The voltage value obtained at N+1 is the sampling time t immediately after the second time T2 N+1 The voltage value obtained at N are sampled voltage values ​​following

[0050] Next, an offset period T is calculated based on the first time difference Δts, the second time difference Δte, and the number N of sampling data for approximately one period centered on the selected period. cycle Calculate the offset period T cycle can be calculated using the following formula (3).

number

[0051] Here, N is the number of sampling times from the sampling time t1 immediately after the first time T1 to the sampling time t2 immediately before the second time T2. N That is, N is the number of sampling data from sampling time t0 to sampling time t N+1 Excluding the sampling data in the offset period T cycle is the number of sampling data corresponding to

[0052] 5, the control unit 12 acquires a set of transition data from the set of sampling data at multiple points in approximately one cycle extracted in step S504 (step S508). The transition data is a set of voltage values ​​obtained when the sampling start time of the extracted sampling data for approximately one cycle is shifted to a first time T1.

[0053] In calculating the set of transition data, first, the sampling time t0 immediately before the first time T1 to the sampling time t2 immediately after the second time T2 is calculated. N+1 In a set of sampling data spanning a period, at a sampling time t n Sampling data V in n and sampling time t n The next sampling time t n+1 Sampling data V in n+1 Find the linear approximation of the line segment with both ends at and , where n is an integer between 0 and N.

[0054] Next, the control unit 12 calculates transition data V based on the obtained approximation equation, with the timing at which the voltage becomes the offset value as a reference. Specifically, the control unit 12 calculates transition data V V that is shifted from a certain sampling time by a predetermined time based on the offset period, based on the approximation equation. sft The predetermined time to shift is calculated as the transition data V sft Calculate the first interval T int1 The first interval T int1 is the transition data V sft is the interval for calculating the offset period T cycle Based on the sampling time t0 to sampling time t N+1 Until the first interval T int1 The transition data is calculated for each time period, and a set of transition data is obtained.

[0055] Specifically, the set of transition data can be calculated from the following equation (4).

number

[0056] where t n is the nth sampling time in the selected period. n is the sampling time t n The voltage value measured at n+1 is the sampling time t n The next sampling time t n+1 is the voltage value measured at

[0057] Also, V sft is transition data. The transition data is a data set that is generated from the sampling time to a predetermined shift time (T sft -t n ) is the data obtained when the sampled voltage value is shifted by V sft (m) is the first interval T int1 The first transition data V is the mth transition data (m is an integer between 1 and M). sft(1) is the voltage value at the first time T1, which is the offset value. By incrementing m from 1 to M, the first interval T int1 A set of transition data including transition data for each can be calculated.

[0058] M is the number of transition data to be calculated and is an arbitrary integer. M can be determined by the value of the sampling frequency relative to the power supply frequency, and ideally, at least one piece of data should be sampled between the transition data to be calculated. For this reason, the upper limit can be set to "power supply frequency sampling frequency x offset period T cycle." For example, if the power supply frequency is 50 Hz and the sampling frequency is 8 kHz, M is 8 kHz x 20 ms / 2, or 80.

[0059] T sft is calculated using the following equation (5).

number

[0060] T cycle / M is the offset period T cycle is divided by M, and is the interval for calculating the transition data Vsft (first interval T int1 ) The first interval T int1 is the offset period T cycle m is an integer between 1 and M.

[0061] T sft is the transition data V sft That is, the time when T sft is a time period that starts from the first time T1, which corresponds to the intersection CP1 where the voltage waveform when two adjacent sampled data are linearly approximated intersects with the offset value, and continues for the first interval T int1 The time is separated by 1000. sft (m) is the time of the mth transition data. For example, the time T sft (1) is the first time T1 at which the offset value intersects with the line segment L1 (FIG. 3) whose two ends are the voltage values ​​V0 and V1 in the set of extracted sampling data for approximately one cycle.

[0062] As described above, from the formulas (4) and (5), the first interval T int1 Transition data can be calculated for each of the time periods, and a set of transition data can be calculated.

[0063] Alternatively, in another example, the set of voltage transition data may be calculated from the following equation (6).

number

[0064] The transition data is an offset period T cycle When calculating over j offset periods, there are M pieces of transition data in one offset period, so the number of pieces of transition data included in the transition data set is M×j, where m is an integer between 1 and M×j.

[0065] The above has been explained using an example of the voltage measured by the watt-hour meter 10, but similarly to the voltage, (a set of) transition data for the current can also be calculated from the following equation (7) or equation (8).

number

[0066]

number

[0067] According to the present disclosure, the set of transition data can be calculated from the sampling data acquired in step S504. Therefore, without changing the sampling interval by the watt-hour meter 10 or performing additional sampling, a set of transition data synchronized with the offset period of the commercial power supply can be obtained from the sampling data of the voltage measured by the watt-hour meter 10.

[0068] Furthermore, according to the present disclosure, a set of transition data based on the offset period can be obtained without considering the influence of fluctuations due to the commercial power frequency. Therefore, even in areas with different commercial power frequencies, any number of transition data synchronized with the offset period can be obtained without changing the hardware structure related to the sampling frequency of the watt-hour meter 10. In other words, a frequency-free watt-hour meter 10 can be configured without changing the hardware structure.

[0069] 5, the process of calculating the set of additional data based on steps S510 and S512 will be described. The additional data is data obtained at a timing based on the offset period, and is obtained at the first interval T int1 (T cycle / M) int2 The additional data is a set of voltage values ​​for each interval T int1 The voltage data in the second interval T int2 can be interpolated using the data.

[0070] In step S510, the control unit 12 calculates a data set consisting of additional data based on the sampling data at a predetermined period. The data set consisting of additional data is calculated by dividing the data set by the first interval T int1 The second interval T is a fraction of int2 The second interval T int2 is the first interval T shown in equation (5). int1 (T cycle / M) divided by an integer i, where i is an integer equal to or greater than 1, for example, 3.

[0071] Note that the processes shown in FIG. 5 are merely exemplary, and the order of the processes may be changed, and processes may be added or deleted. For example, a data set consisting of additional data may be calculated from the set of transition data after calculating the transition data. That is, as shown in FIG. 5, the transition data calculation process of step S508 may be performed first, followed by the additional data calculation process of step S510. Alternatively, the data set consisting of additional data may be calculated directly from the set of sampling data based on equation (4) and the following equation (9). That is, following step S506, the processes of step S508 and step S510 may be performed simultaneously.

[0072] The additional data is calculated from the following equation (9) for the second interval T int2 Every time T sft and then introduce this into the above equation (4).

[0073]

number

[0074] In equation (9), m is incremented by 1 from 1 to iM, and the offset period T cycle A second interval T int2 For example, if i is 3, the first interval T int1Additional data can be calculated at intervals of one-third of the set of transition data calculated in step S508, thereby obtaining a set of data three times larger than the set of transition data calculated in step S508. In other words, the set of transition data can be doubled. According to the present disclosure, doubling refers to increasing by an integer multiple.

[0075] In addition, the second interval T int2 The integer multiple of the first interval T int1 In this case, the additional data is the transition data V sft Therefore, the first interval T int1 For example, in step S508, the data obtained every first interval T int1 (=T cycle / M) for each transition data V sft If the first interval T int1 It is not necessary to calculate the data for each item as additional data.

[0076] FIG. 6A illustrates a first interval T int1 FIG. 6B illustrates a set of transition data obtained at a second interval T int2 6B shows an example of a set of transitional data, including an additional data set obtained every first interval T int1 At half the time, the first interval T int1 In this example, the dataset of transition data can be approximately doubled by including a dataset of additional data.

[0077] In one example, the sampling data of the predetermined period used to calculate the additional data in step S510 is sampling data of the first period of the voltage corresponding to the set of transition data calculated in step S508. That is, the set of transition data and the set of additional data are calculated based on sampling data of the same period.

[0078] In another example, the sampling data of a predetermined period used to calculate the additional data in step S510 is a second period different from the first period of the voltage corresponding to the set of transition data calculated in step S508. The control unit 12 calculates the set of transition data based on the sampling data of a certain predetermined first period, and calculates the set of additional data based on the sampling data of a period different from the first period. In this case, it is preferable that the shape of the voltage waveform (waveform based on the sampling data) for one period of the voltage corresponding to the set of transition data and the second period be approximately the same.

[0079] According to the present disclosure, it is possible to increase the set of transition data representing voltage values ​​synchronized with the commercial power frequency without changing the sampling frequency. As a result, the first interval T int1 This allows for obtaining data that is multiple times (for example, three times) the transition data obtained by the above method. This allows for a more detailed representation of the time change of the AC signal measured by the watt-hour meter 10 from its digital data, enabling detailed analysis such as FFT analysis using the additional data set.

[0080] Furthermore, by analyzing the time variation (signal waveform) of the AC signal based on a transition data set including a set of additional data, detailed FFT analysis becomes possible, making it possible to analyze what monitored devices 30 are connected to the electricity meter 10.

[0081] T cycle ...Offset period T1…1st time T2…Second time t n …Sampling time 10…Electric power meter 12...Control unit 14...Terminal section 16...Communication control unit 30...Monitored equipment

Claims

1. 1. A method for determining a data set of an AC signal measured by a watt-hour meter synchronized with a timing of an offset value, comprising: A step of obtaining a set of sampling data obtained by sampling the AC signal measured by the watt-hour meter at a sampling interval of the watt-hour meter; a step of calculating transition data, the transition data being shifted by a predetermined time from each sampling time of the sampling data, the predetermined time being based on a timing at which the AC signal passes through an offset value in an increasing direction; a step of acquiring a transition data set including the transition data, the transition data set including transition data of a first interval corresponding to a first offset period from a first time point of the timing at which the AC signal passes through the offset value to a second time point of the timing at which the AC signal passes through the next offset value in a direction in which the AC signal increases centered on the selected one period; acquiring a second transition data set in a second offset period from a third time point at which the AC signal passes through the offset value to a fourth time point at which the AC signal passes through the next offset value in an increasing direction of the AC signal centered on a period different from the selected period, and obtaining additional data having a second interval shorter than the first interval from the second transition data set; obtaining an additional data set comprising said additional data; including the additional data set in the transitional data set; A method comprising:

2. 1. A watt-hour meter for determining a data set of an AC signal measured by the watt-hour meter synchronized with a timing of an offset value, the data set comprising at least one processor, the data set being synchronized with a timing of an offset value, the data set comprising at least one processor executing a program for causing the watt-hour meter to A step of obtaining a set of sampling data obtained by sampling the AC signal measured by the watt-hour meter at a sampling interval of the watt-hour meter; a step of calculating transition data, the transition data being shifted by a predetermined time from each sampling time of the sampling data, the predetermined time being based on a timing at which the AC signal passes through an offset value in an increasing direction; a step of acquiring a transition data set including the transition data, the transition data set including transition data of a first interval corresponding to a first offset period from a first time point of the timing at which the AC signal passes through the offset value to a second time point of the timing at which the AC signal passes through the next offset value in a direction in which the AC signal increases centered on the selected one period; acquiring a second transition data set in a second offset period from a third time point at which the AC signal passes through the offset value to a fourth time point at which the AC signal passes through the next offset value in an increasing direction of the AC signal centered on a period different from the selected period, and obtaining additional data having a second interval shorter than the first interval from the second transition data set; obtaining an additional data set comprising said additional data; including the additional data set in the transitional data set; Execute Electric energy meter.

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