JP2001305165A - Arithmetic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arithmetic method which is small in the storage capacity of an internal memory, able to perform operation again for an input signal having been operated once, and permits waveform observation adaptive to a pretrigger function, etc., in single-sweeping-operation mode. SOLUTION: A measuring person inputs a voltage to be measured to a voltage input terminal 1, a current to be measured to a current input terminal 5, and specific information needed to specify an arbitrary sampling section to a sampling section input terminal 11. For processing, two P-P compression values, 6 samplings, and 18 pieces of partial operation data are stored in the memory from two pieces of instantaneous data obtained by (k) for each sampling section as a process unit. According to the data by the sections, data in specified sections are computed. The storage capacity of the internal memory is smaller than that of processing in which all the pieces of instantaneous data are stored.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an operation method,
More specifically, the present invention relates to a method of calculating effective values of voltage, current, and power to obtain predetermined calculation data from measured instantaneous data.

[0002]

2. Description of the Related Art With the recent spread of digital memories and high-speed AD converters, arithmetic methods using digital memories have been developed. In the operation performed by the digital measuring instrument, all the digital processing is performed by a processor such as a DSP.
Errors in measurement results are reduced. For example, when measuring an AC circuit, the measured values of the effective voltage value, the effective current value, and the effective power value are stabilized, and accurate measurement of the instantaneous waveform can be performed. The effective value of the signal under measurement other than the sine wave including harmonics can be measured,
When a pre-trigger function or the like in the single sweep operation mode is used, a signal under measurement having a non-repetitive waveform can be observed.

FIG. 8 is a block diagram of a digital measuring instrument that executes a conventional calculation method. The amplifier 2 normalizes the value of the voltage input from the voltage input terminal 1 and inputs the result to the AD converter 3 and the zero-cross detector 4 as an analog voltage signal 101. The AD converter 3 outputs the voltage data v _i
And the zero-cross detector 4 inputs the zero-cross voltage signal 102 as its output to the DSP 9. Amplifier 6
The value of the current input from the current input terminal 5 is normalized and input to the AD converter 7 and the zero-cross detector 8 as an analog current signal 103. The AD converter 7 inputs the output current data a _i and the zero-cross detector 8 inputs the output zero-cross current signal 104 to the DSP 9, respectively. D
SP9 includes voltage data v _i , current data a _i , and zero-cross voltage signal 10 forming digital instantaneous data during the measurement period.
2 and the zero-cross current signal 104 are all stored in the memory 10.

[0004] After the measurement period ends, the digital measuring instrument uses the zero-cross voltage signal 102 or the zero-cross current signal 104 stored in the memory 10 to measure from the first rising (or falling) of the measurement start to the last rising (or falling). ) obtaining the N period until (and i = m _f ~m _e as the period). Voltage rms value V _rms , current rms value A _rms , and active power value W
Is based on the voltage data v _i , the zero-cross voltage signal 102, the current data a _i , and the zero-cross current signal 104,
It is calculated using the following equations (1) to (3).

(Equation 1) After the measurement period ends, the DSP 9 displays on the output device 14 the calculation results obtained by Expressions (1) to (3).

[0005] In DSP9 employing real-time measurements, during the measurement period, v _i ² partial operation data from v _i and a _i of the instantaneous data, a _i ^2, and the v _i × a _i respectively calculated, respectively Are added and totaled. After the measurement period ends, the DSP 9 calculates the sum of the respective partial operation data.
V _rms , A _rms , and W are obtained and displayed on the output device 14.

When the digital measuring instrument has a waveform observing function, all the instantaneous data are stored in the memory 10 during the observing period, and after the observing period, the waveform of the input signal, the effective voltage _Vrms , the current The effective value A _rms and the active power value W are displayed on the output device 14.

[0007]

In a digital measuring instrument that executes a conventional arithmetic method, all instantaneous data acquired during a measurement period is stored in a memory 10 in order to measure an AC signal and observe a waveform. And the storage capacity of the memory 10 is large.

Further, if real-time measurement is employed to reduce the storage capacity of the memory 10, it is impossible to execute the operation again on the input signal once the operation has been completed. In this case, free measurement such as checking an input signal while observing a waveform and performing a predetermined calculation by designating an arbitrary sampling section is limited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a small storage capacity of a built-in memory, and performs a recalculation for an input signal once completed. It is another object of the present invention to provide a calculation method capable of observing a waveform that can support a pre-trigger function in a single sweep operation mode.

[0010]

In order to achieve the above object, a calculation method according to the present invention performs a predetermined calculation process on instantaneous data obtained by sequentially sampling a signal under measurement at a predetermined sampling rate. A zero-crossing signal is generated from the signal under measurement, and the sampling interval is determined based on the zero-crossing signal based on the zero-crossing signal. A first period from the start of the section until the first zero-cross in the predetermined direction occurs in the sampling section, and a second period after the first period until the last zero-cross in the predetermined direction occurs in the sampling section. And a third period following the second period
, The instantaneous data is arithmetically processed for each of the first to third periods to obtain partial operation data, and the sampling number of the instantaneous data and the partial operation data are stored in a memory for each of the periods, According to another feature of the present invention, operation data within an arbitrary time including one or more sampling intervals is calculated based on the partial operation data.

According to the operation method of the present invention, by storing the partial operation data obtained in each sampling section, the storage capacity can be reduced as compared with the operation method in which all the instantaneous data is stored and operated.

In the calculation method according to the present invention, the first to third periods may be defined as a zero-cross point at which the signal under measurement shifts from positive to negative and a zero-cross point at which the signal under measurement shifts from negative to positive. It is preferable to determine both of the points and analyze the obtained partial operation data to determine which of the zero-cross points the partial operation data obtained from is adopted. In this case, partial calculation data for obtaining an accurate measurement value of the signal under measurement is used for the designated sampling section.

In the calculation method according to the present invention, the signal under measurement may include a voltage and a current, and the calculation data may include at least one of a voltage effective value, a current effective value, and an active power value.

It is a preferred embodiment of the present invention that the partial operation data includes the maximum value and the minimum value in each period, and the waveform data of the signal under measurement is obtained. In this case, after or before the input of the signal under measurement, an arbitrary sampling section is designated, and the measurement for obtaining the effective voltage value and the like and the waveform observation can be performed any number of times.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operation method according to the present invention will be described based on an embodiment of the present invention with reference to the drawings. FIG. 1 is a block diagram of a digital measuring instrument that executes the calculation method according to the first embodiment of the present invention. The measurer inputs the voltage to be measured to the voltage input terminal 1, inputs the current to be measured to the current input terminal 5, and specifies information necessary for specifying an arbitrary sampling section to the sampling section input terminal 1.
Enter 1 Digital measuring instruments are amplifiers 2, 6, AD
It comprises converters 3, 7, zero-cross detectors 4, 8, DSP 9, memory 10, sampling interval input device 12, and output device 14.

The amplifier 2 normalizes the signal input from the voltage input terminal 1 and inputs it as an analog voltage signal 101 to the AD converter 3 and the zero-cross detector 4. AD converter 3, an analog voltage signal 101 to AD conversion, and inputs the DSP9 as voltage data v _i. Zero cross detector 4
Converts the waveform into a pulse signal of either an H level or an L level according to the polarity of the analog voltage signal 101 and inputs it to the DSP 9 as a zero-cross voltage signal 102. The amplifier 6 normalizes the signal input from the current input terminal 5,
The analog current signal 103 is input to the AD converter 7 and the zero-cross detector 8. AD converter 7, an analog current signal 103 to the AD converter, DSP as the current data a _i
Enter 9 The zero-cross detector 8 converts the waveform according to the polarity of the analog current signal 103 and inputs the converted signal to the DSP 9 as a zero-cross current signal 104.

The zero-cross signal used in this specification is
Focusing only on the polarity or sign of the measured signal, the signal does not have the absolute value information of the amplitude. For example, the signal takes "1" during the positive period of the signal and "0" during the negative period of the signal.

The sampling section input device 12 inputs necessary control signals to the DSP 9 based on the necessary designation information input from the sampling section input terminal 11. DS
P9 performs a section control process of measuring an AC signal for a sampling section specified based on the zero-cross voltage signal 102, the zero-cross current signal 104, and the control signal. DSP9 is in real time during the measurement period, and the effective value calculated based on voltage data v _i and the current data a _i instantaneous data, stores only partial operation data in the memory 10. After completion of the measurement, the DSP 9 calculates from the stored partial operation data, and inputs necessary output information such as a processing status and a calculation result to the output device 14. The output device 14
The output information is printed out, stored in an external storage device, or displayed on the screen as instructed by the measurer.

Here, the effective value calculation and the section control processing performed by the digital measuring instrument of FIG. 1 to measure an AC signal will be described. This effective value calculation, from the voltage data v _i and the current data a _i instantaneous data, v _i ^2, a _i ² and,, v _i ×
a _i calculates the respective works of, [sigma] v _i ² sums respectively,? a _i ^2, and is intended to determine Σ a (v _i × a _i).

FIG. 2 is a time chart of a specific example 1 of each signal handled by the digital measuring instrument of FIG. DSP9
Are voltage data v _{i of} instantaneous data, current data a _i , zero-cross voltage signal 102, and zero-cross current signal 104
Treats a period during which k sampling numbers are obtained as one sampling section. Since the DSP 9 performs the section control process based on the voltage, the zero-cross voltage signal 102
Is selected as a section control signal for the section control processing. The value of k is the number of samples in one sampling interval,
A sufficiently large value (2k） 24) is adopted so that the characteristics of the signal under measurement can be extracted after sampling.

[0021] DSP9 is the sampling interval K _j is a j-th one sampling interval to monitor the rise of the zero-crossing voltage signal 102, performs interval control process related to the rise in three periods. The first period from the start time of the sampling interval K _j until the first rising time of the zero-crossing voltage signal 102, and writes the number of the sampled instantaneous data to the area n _J1H memory 10. At the same time, the partial operation data Σv _i ² , Σa _i ² , and
Σ (v _i × a _i ) is stored in areas Sv _j1H , Sa _j1H , and
_Write to Sw _{j1H respectively} .

Next, for the second period from the first rising time of the zero-cross voltage signal 102 to the last rising time of the zero-cross voltage signal 102, the number of sampled instantaneous data is written to the area n _j2H of the memory 10. . At the same time, [sigma] v _i ² parts operation data of the second period,? A _i ^2, _{and, Σ (v i × a i} ) of the memory 10 area Sv _j2h, Sa _j2h, and writes each to Sw _j2h.

Furthermore, for the third period from the last rising time of the zero-crossing voltage signal 102 to the end time of the sampling interval K _j, it is written the number of the sampled instantaneous data to the area n _J3H memory 10. At the same time, Σv _i ² , Σa _i ² , and Σ (v _i × a _i ) of the partial operation data in the third period
_Are written in the areas Sv _j3H , Sa _j3H , and Sw _j3H of the memory 10, _respectively , and the section control processing for the sampling section K _j ends.

[0024] If the rising edge of the zero-crossing voltage signal 102 in the sampling interval K _j is present only once, interval control process of the first period and the third period is carried out in the same manner as described above. The section control processing of the second period is performed by the areas n _j2H , Sv
_Write 0 to all of _j2H , Sa _j2H and Sw _j2H .

[0025] If the rising edge of the zero-crossing voltage signal 102 in the sampling interval K _j is not present once for the entire period from the start time of the sampling interval K _j to the end time of the sampling interval K _j, interval control Lifetime In the process, the number of instantaneous data is written to the area n _{j3H of the} memory 10. At the same time, Σv _i ² , Σa _i ² , and Σ
(V _i × a _i) the area Sv of the memory ₁₀ j3H, Sa j3H, and, Sw
_Write to _{j3H respectively} . At the same time, the areas n _j1H , S
v _j1H , Sa _j1H , Sw _j1H , n _j2H , Sv _j2H , Sa _j2H , and Sw
_Write 0 to all of _j2H .

Further, DSP 9 is the sampling interval K _j, is also simultaneously monitored falling zero-cross voltage signal 102, similarly to the interval control process related to the rise, also performs interval control process related to falling.

FIG. 3 is a diagram showing the contents stored in the memory 10 of FIG. When measuring the AC signal as a measurement period from the time t1 in FIG. 2 to the time t5, the stored contents per one sampling interval, the conventional storing all the instantaneous data, instantaneous voltage data v _i and the current data a _i In order to store all data, 2 × k areas are required. When the present embodiment is adopted, the storage contents per sampling section are, as shown in FIG. 3, 6 and 18 areas for storing the number of samplings and the partial operation data, respectively. However, since 24 areas are sufficient, the storage capacity of the memory 10 can be reduced as compared with the conventional case.
Further, even if the value of the number of samples k is increased in order to cope with higher precision, the storage capacity of the memory 10 does not change.

[0028] After completion of the measurement period, the sampling period the input device 12 from the sampling interval K ₁ to the sampling interval K ₄ is designated as the calculation target range, the effective voltage value
V _rms , current effective value A _rms , and active power value W are obtained. Methods for specifying the calculation target range include an external specification method and an internal specification method. The external designation method is a method in which the measurer externally inputs designation information via the sampling section input terminal 11. The internal designation method is a method in which the sampling section input device 12 compares the voltage data v _i or the current data a _i with their preset threshold values, respectively, and internally inputs designation information based on the comparison result. It is.

[0029] DSP9 is the sampling interval K _j to calculate target range is specified, the number sampling memory 10 n
_j1H , _nj1L , _nj2H , and _nj2L are sequentially referred to, and n
_{If j1H} ≠ 0 or n _j2H ≠ 0, select a data string related to the rise, and if n _j1L ≠ 0 or n _j2L ≠ 0, select a data string related to the _fall .

When a plurality of sampling sections are continuously specified in the calculation target range, the sampling numbers n _j1H and n _j2H or the sampling numbers n _j1L and n _j2L are set for the first and last sampling sections K _j . It is sequentially determined whether it is other than 0 or not. If the rising data sequence is selected first, n _j2H = 0
If n _j1H , the first period of the row with the region n _j1H is selected as the start period and the end period. If n _j2H ≠ 0, the second period of the row with the region n _j2H is set as the start period and the end period. Select each one.

When the falling data sequence is selected first, n
_{If j2L} = 0, the first period of the row with the region n _j1L is selected as the start period and the end period, respectively. If n _j2L ≠ 0, the second period of the row with the region n _j2L is selected as the start period and the end period. Select each in the end period.

[0032] exist between the start time of the first sampling interval K _j to the end time of the last sampling interval K _j, and, partial operation data sampling number is other than 0 is calculation.

Here, for the analog voltage signal 101 and the analog current signal 103 in FIG. 2, a sampling section is designated as a calculation target range by an external designation method, and D
A specific example of the calculation performed by SP9 will be described. When the sampling interval K ₁ ~K ₃ is designated in the calculation target range as the trial example 1,
The data sequence relating to the rise is selected first, and the total sampling number n _K13 of the calculation target range is obtained by Expression (4). _{n K13 = n 12H + (n} 13H + n 21H) + n 22H + (n 23H + n 31H) ···· (4) the effective voltage value for the sampling interval K ₁ ~K _3
VrmsK13 , RMS current _ArmsK13 , and active power W
_K13 is calculated using the following equations (5) to (7). V _rmsK13 = {[{Sv _12H + (Sv _13H + Sv _21H ) + Sv _22H + (Sv _23H + Sv _31H )}} / n _K13 ] ・ ・ ・ (5) A _rmsK13 = √ [{Sa _12H + (Sa _13H + Sa _21H ) + Sa _22H + (Sa _23H + Sa _31H )} / n _K13 ] (6) W _K13 = {Sw _12H + (Sw _13H + Sw _21H ) + Sw _22H + (Sw _23H + Sw _31H) )} / n _K13 ··· (7)

When the sampling sections K _{2 to} K ₄ are specified in the calculation target range as a trial example 2, the data sequence relating to the falling is selected first, and the total sampling number n of the calculation target range is selected.
_K24 is obtained by equation (8). _{n K24 = n 22L + (n} 23L + n 31L) + (n 33L + n 41L) ···· (8) a voltage effective value for the sampling interval K ₂ ~K _4
VrmsK24 , RMS current _ArmsK24 , and active power W
_K24 is calculated using the following equations (9) to (11). V _rmsK24 = {[{Sv _22L + (Sv _23L + Sv _31L ) + (Sv _33L + Sv _41L )}} / n _K24 ] (9) A _rmsK24 = √ [{Sa _22L + (Sa _23L + Sa _31L ) + (Sa _33L + Sa _41L )} / n _K24 ] ・ ・ ・ (10) W _K24 = {Sw _22L + (Sw _23L + Sw _31L ) + (Sw _33L + Sw _41L )} / n _K24・ ・ ・・ (11)

FIG. 4 is a time chart of a specific example 2 of each signal handled by the digital measuring instrument of FIG. A specific example of calculation performed by the digital measuring instrument with a calculation target range specified by the internal specification method for the analog voltage signal 101 and the analog current signal 103 in FIG. DSP9
Performs internal specifying the value of the analog current signal 103 is a calculation target range sampling interval exceeding the current threshold I _th. The calculation range is the sampling interval K
_{2 to} K ₃ are selected, and the data sequence related to the rise is selected first, and the total sampling number n _K23 in the calculation target range is obtained by Expression (12). _{n K23 = n 22H + (n} 23H + n 31H) + n 32H ···· (12) effective voltage for the sampling interval K ₂ ~K _3
VrmsK23 , RMS current _ArmsK23 , and active power W
_K23 is calculated using the following equations (13) to (15). _{V rmsK23 = √ [{Sv 22H} + (Sv 23H + Sv 31H) + Sv 32H} / n K23] ···· (13) A rmsK23 = √ [{Sa 22H + (Sa 23H + Sa 31H) + Sa 32H } / n _K23 ] ··· (14) W _K23 = {Sw _22H + (Sw _23H + Sw _31H ) + Sw _32H } / n _K23 ··· (15)

According to the above embodiment, by storing the partial operation data obtained in each sampling section,
Compared to the calculation method of storing and calculating all instantaneous data,
The storage capacity is small.

In addition, for an input signal for which an operation has been completed, an operation for measuring an AC signal many times can be executed by designating an arbitrary sampling section.

FIG. 5 is a block diagram of a digital measuring instrument for executing the calculation method according to the second embodiment of the present invention. The measurer inputs a trigger signal indicating the trigger time to the external input terminal 13. The DSP 9 satisfies the predetermined condition that the trigger signal is input from the external input terminal 13 or the result of comparing the voltage data v _i or the current data a _i with their preset threshold values, respectively. By doing so, the trigger time for the signal under measurement is recognized.

Which part is displayed for the signal under measurement is determined by setting the trigger position. As the trigger position, a time after an elapse of a delay time arbitrarily set from the trigger time is selected by the trigger delay function.

FIG. 6 is a diagram showing an outline of waveform observation in the single sweep operation mode. The positions Q1 to Q17 correspond to the start addresses of the areas for each sampling section on the memory 10. As shown in the figure, in the waveform observation, new observation data is stored from the position on the memory 10 where the subscript j of the position Q _j is incremented by one for each sampling interval. When the movement on the memory 10 moves to the position Q17 and the observation data is stored, the observation data corresponding to the next sampling section is stored by moving to the position Q1.

The operator specifies the single sweep operation mode, and
Observe the waveform of the signal under measurement with a non-repetitive waveform. DSP9
Recognizes the position Q12 as a trigger position,
Position Q6 is designated as a pre-trigger position, and position Q3 is designated as a post-trigger position because 14 sampling sections are displayable periods. In the waveform observation, the observation data is stored up to the sampling section at the position Q3, the storage operation is stopped at that position, and the observation data of each sampling section in the displayable period from the position Q6 to the position Q3 is displayed.

The measurer moves the displayable period forward or backward by operating the trigger position by the trigger delay function or the like in the single sweep operation mode, and arbitrarily displays the observation data stored in the pre-trigger period or the post-trigger period. As a result, high-performance waveform observation can be performed on the signal under measurement having a non-repetitive waveform.

FIG. 7 is a diagram showing the contents stored in the memory 10 of FIG. The memory 10 has a storage capacity capable of storing compressed data, sampling numbers, and partial operation data corresponding to 17 sampling sections. This figure shows only the minimum data necessary for observing the waveform corresponding to the voltage of the signal under measurement. The memory 10, including those relating to data not shown, the compression value _{PPv jF, PPv jS, PPa jF} , PPa
_jS, PPw _jF, PPw _jS, sampling number _n j1H ~n j3H, n j1L ~
n _j3L , partial operation data Sv _{j1H to} Sv _j3H , Sa _{j1H to} Sa _j3H , Sw
_{j1H ~Sw j3H, Sv j1L ~Sv j3L} , Sa j1L ~Sa j3L, and, Sw
_{j1L to} Sw _j3L .

[0044] DSP9 is the sampling interval K _j is a processing unit, select two compressed data of the maximum value PPv _jS and minimum PPv _jF from the k voltage data v _i, k pieces of current data a _i selects two compressed data of the maximum value PPa _jS and minimum PPa _jF among the two compressed data of the maximum value PPW _jS and the minimum value PPW _jF from the k power data v _i × a _i Select and store in the memory 10.

According to the above embodiment, since the signal to be measured can be surely recognized by the waveform observation, the calculation target range for measuring the AC signal can be correctly specified. In addition, since the function to arbitrarily display the pre-trigger period or post-trigger period of the single sweep operation can be supported with a small memory capacity, even for the signal to be measured having a non-repetitive waveform, high-function waveform observation and AC signal Measurement becomes easy.

As described above, the present invention has been described based on the preferred embodiment. However, the calculation method of the present invention is not limited to the configuration of the above-described embodiment, but is based on the configuration of the above-described embodiment. Calculation methods with various modifications and changes are also included in the scope of the present invention.

[0047]

As described above, the operation method of the present invention stores partial operation data obtained in each sampling period, thereby making it possible to store all the instantaneous data and perform the operation. The storage capacity is small.

Further, since the signal to be measured can be reliably recognized by observing the waveform, the sampling section for measuring the AC signal can be specified correctly. In addition, since the function to arbitrarily display the pre-trigger period or post-trigger period of the single sweep operation can be supported with a small memory capacity, it is possible to observe a waveform or measure an AC signal of a signal to be measured having a non-repetitive waveform. It becomes easier.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital measuring instrument that executes a calculation method according to a first embodiment of the present invention.

FIG. 2 is a time chart of a specific example 1 of each signal handled by the digital measuring instrument of FIG. 1;

FIG. 3 is a diagram showing storage contents of a memory 10 of FIG. 1;

FIG. 4 is a time chart of a specific example 2 of each signal handled by the digital measuring instrument of FIG. 1;

FIG. 5 is a block diagram of a digital measuring instrument that executes a calculation method according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an outline of waveform observation in a single sweep operation mode.

FIG. 7 is a diagram showing storage contents of a memory 10 of FIG. 5;

FIG. 8 is a block diagram of a digital measuring instrument that executes a conventional calculation method.

[Explanation of symbols]

Reference Signs List 1 voltage input terminal 2, 6 amplifier 3, 7 AD converter 4, 8 zero cross detector 5 current input terminal 9 DSP 10 memory 11 sampling section input terminal 12 sampling section input device 13 external input terminal 14 display device 101 analog voltage signal 102 Zero cross voltage signal 103 Analog current signal 104 Zero cross current signal v _i voltage data a _i current data

Claims (4)

[Claims] An arithmetic method for obtaining arithmetic data by performing predetermined arithmetic processing from instantaneous data obtained by sequentially sampling a signal to be measured at a predetermined sampling rate, wherein a zero-cross signal is obtained from the signal to be measured. Based on the zero-cross signal, the sampling section is generated from the start of the sampling section until a zero-cross in the predetermined direction is first generated in the sampling section based on the zero-cross signal. In a first period, a second period following the first period and lastly generating a zero cross in a predetermined direction in the sampling period, and a third period following the second period. In each of the first to third periods, the instantaneous data is subjected to arithmetic processing to obtain partial operation data. And storing the partial operation data in a memory, and calculating operation data within an arbitrary time including one or more sampling intervals based on the partial operation data. 2. The first to third periods are obtained for both a zero-crossing point at which the signal under measurement shifts from positive to negative and a zero-crossing point at which the signal under measurement shifts from negative to positive. The method according to claim 1, wherein the obtained partial operation data is analyzed to determine which of the zero-cross points the partial operation data is to be adopted from. 3. The signal according to claim 1, wherein the signal under measurement includes a voltage and a current, and the calculation data includes at least one of a voltage effective value, a current effective value, and an active power value. Calculation method. 4. The calculation method according to claim 1, wherein the partial calculation data includes a maximum value and a minimum value in each period, and obtains waveform data of the signal under measurement.