JP2011117794A - Device for measuring effective value - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure also an average value more accurately together with and simultaneously with an effective value, in a measuring object signal of which the period is unknown. <P>SOLUTION: The device includes a windowing processing part 4 which performs the windowing processing of a prescribed number of sampling data D1 (data D2) about the measuring object signal S1 and outputs them as window data D3, an effective value measuring part 5 which executes the effective value measuring processing of calculating the effective value Drms of the measuring object signal S1 on the basis of the window data D3 and outputting it, an AC-DC average value measuring part 6 which executes the AC-DC average value measuring processing of calculating an AC-DC average value Dava of the measuring object signal S1 on the basis of the window data D3 and outputting it, and a DC average value measuring part 7 which executes the DC average value measuring processing of calculating a DC average value Davd of the measuring object signal S1 on the basis of the window data D3 and outputting it, and the effective value measuring part 5, the AC-DC average value measuring part 6 and the DC average value measuring part 7 execute the effective value measuring processing, the AC-DC average value measuring processing and the DC average value measuring processing in parallel. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an effective value measuring apparatus for measuring an effective value of a signal to be measured.

  As this type of effective value measuring device, an effective value measuring device described in the following patent document is known. This effective value measuring apparatus includes a square circuit that squares sampling data of a signal to be measured, an RMS digital filter (low-pass filter) that filters the squared sampling data, and a square root of the filtered data. And a square root circuit that calculates and outputs the effective value as an effective value, so that the effective value can be measured without knowing the period of the measurement target signal whose period is unknown.

Japanese Patent Laid-Open No. 10-232250 (page 4-6, FIG. 6)

  However, the above effective value measuring apparatus has the following problems to be solved. That is, further improvement in the measurement accuracy of the effective value has been desired, but there is a problem to be solved that the current measurement accuracy in the conventional effective value measurement device cannot meet this demand. In addition, there is a request to simultaneously measure the average value as well as the effective value of the signal to be measured, but there is a problem to be solved that this conventional effective value measuring apparatus cannot cope with this request.

  The present invention has been made to solve the above-described problem, and an effective value measuring apparatus capable of measuring an average value together with an effective value with higher accuracy and simultaneously with an effective value for a measurement target signal whose cycle is unknown. The main purpose is to provide

  In order to achieve the above object, the effective value measuring apparatus according to claim 1, a windowing processing unit that performs windowing processing on a predetermined number of sampling data of a measurement target signal and outputs the result as window data; and the predetermined number A square processing unit that squares the window data and outputs it as square data, a first average processing unit that averages the predetermined number of square data and outputs the first average data, and calculates a square root of the first average data An effective value including a square root calculating unit that outputs the square root data as a square root data, and a first correction unit that corrects the attenuation during the windowing process with respect to the square root data and outputs the result as an effective value of the signal to be measured. An effective value measuring unit that executes measurement processing, an absolute value processing unit that calculates an absolute value of the predetermined number of window data and outputs the absolute value data, and averages the predetermined number of absolute value data And an AC / DC average processing unit that outputs the AC / DC average data, and a second correction that corrects an attenuation during the windowing process for the AC / DC average data and outputs the AC / DC average value of the measurement target signal. And an AC / DC average value measurement unit that executes an AC / DC average value measurement process, and the RMS value measurement unit and the AC / DC average value measurement unit include the RMS value measurement process and the AC / DC average value. Run the measurement process in parallel.

  The effective value measuring apparatus according to claim 2, wherein a windowing processing unit that performs windowing on a predetermined number of sampling data for the measurement target signal and outputs the result as window data; and the predetermined number of the window data A square processing unit that squares and outputs square data, a first average processing unit that averages the predetermined number of square data and outputs the first average data, and calculates a square root of the first average data to calculate square root data And a first correction unit that corrects the attenuation at the time of the windowing process for the square root data and outputs the result as an effective value of the measurement target signal, and executes an effective value measurement process. An effective value measurement unit that averages the predetermined number of window data and outputs the averaged DC data as DC average data, and a reduction in the windowing process for the DC average data. A DC average value measuring unit that has a third correction unit that corrects the minute and outputs the result as a DC average value of the signal to be measured, and executes a DC average value measurement process, and the effective value measuring unit and the DC average The value measurement unit executes the effective value measurement process and the DC average value measurement process in parallel.

  The effective value measuring apparatus according to claim 3, wherein a windowing processing unit that performs windowing on a predetermined number of sampling data of the measurement target signal and outputs the result as window data; and the predetermined number of the window data A square processing unit that squares and outputs square data, a first average processing unit that averages the predetermined number of square data and outputs the first average data, and calculates a square root of the first average data to calculate square root data And a first correction unit that corrects the attenuation at the time of the windowing process for the square root data and outputs the result as an effective value of the measurement target signal, and executes an effective value measurement process. An effective value measuring unit that calculates an absolute value of the predetermined number of the window data and outputs the absolute value data, and averages the predetermined number of the absolute value data to obtain an AC / DC average An AC / DC average processing unit that outputs the data as a data, and a second correction unit that corrects an attenuation during the windowing process for the AC / DC average data and outputs the AC / DC average value of the measurement target signal. And an AC / DC average value measurement unit that executes AC / DC average value measurement processing, a DC average processing unit that averages the predetermined number of the window data and outputs the averaged DC data, and the DC average data A DC average value measurement unit that performs a DC average value measurement process, and includes a third correction unit that corrects the attenuation during windowing processing and outputs the DC average value of the signal to be measured as a DC average value; The measurement unit, the AC / DC average value measurement unit, and the DC average value measurement unit execute the effective value measurement process, the AC / DC average value measurement process, and the DC average value measurement process in parallel.

  According to a fourth aspect of the present invention, there is provided a square value processing unit that squares a predetermined number of sampling data of a measurement target signal and outputs the squared data as a square data, and a first windowing unit for the predetermined number of the squared data. A first windowing processing unit that performs processing and outputs the first window data; a first average processing unit that averages the predetermined number of the first window data and outputs the first window data; and A square root calculation unit that calculates a square root and outputs the result as square root data; and a first correction unit that corrects an attenuation during the first windowing process for the square root data and outputs the result as an effective value of the measurement target signal. An effective value measurement unit that executes an effective value measurement process, an absolute value processing unit that calculates an absolute value of the predetermined number of the sampling data and outputs the absolute value as absolute value data, and the predetermined number of the absolute value A second windowing processing unit for performing a second windowing process on the data and outputting it as second window data; an AC / DC averaging process for averaging the predetermined number of second window data and outputting the result as AC / DC average data And a second correction unit that corrects the attenuation during the second windowing process with respect to the AC / DC average data and outputs the AC / DC average value of the measurement target signal. An AC / DC average value measuring unit that executes processing, and the RMS value measuring unit and the AC / DC average value measuring unit execute the RMS value measuring process and the AC / DC average value measuring process in parallel.

  In addition, the effective value measuring apparatus according to claim 5 is a square processing unit that squares a predetermined number of sampling data of a measurement target signal and outputs the squared data, and a first windowing unit for the predetermined number of the squared data. A first windowing processing unit that performs processing and outputs the first window data; a first average processing unit that averages the predetermined number of the first window data and outputs the first window data; and A square root calculation unit that calculates a square root and outputs the result as square root data; and a first correction unit that corrects an attenuation during the first windowing process for the square root data and outputs the result as an effective value of the measurement target signal. An effective value measuring unit that executes an effective value measuring process, a third windowing processing unit that performs a third windowing process on the predetermined number of the sampling data and outputs the third windowing data, A DC average processing unit that averages the third window data of a constant and outputs as DC average data, and corrects the attenuation during the third windowing process with respect to the DC average data and corrects the DC of the measurement target signal A DC average value measurement unit that has a third correction unit that outputs an average value and executes a DC average value measurement process, wherein the RMS value measurement unit and the DC average value measurement unit include the RMS value measurement process and The DC average value measurement process is executed in parallel.

  In addition, the effective value measuring apparatus according to claim 6 is a square processing unit that squares a predetermined number of sampling data of a measurement target signal and outputs the squared data, and a first windowing unit for the predetermined number of the squared data. A first windowing processing unit that performs processing and outputs the first window data; a first average processing unit that averages the predetermined number of the first window data and outputs the first window data; and A square root calculation unit that calculates a square root and outputs the result as square root data; and a first correction unit that corrects an attenuation during the first windowing process for the square root data and outputs the result as an effective value of the measurement target signal. An effective value measurement unit that executes an effective value measurement process, an absolute value processing unit that calculates an absolute value of the predetermined number of the sampling data and outputs the absolute value as absolute value data, and the predetermined number of the absolute value A second windowing processing unit for performing a second windowing process on the data and outputting it as second window data; an AC / DC averaging process for averaging the predetermined number of second window data and outputting the result as AC / DC average data And a second correction unit that corrects the attenuation during the second windowing process with respect to the AC / DC average data and outputs the AC / DC average value of the measurement target signal. An AC / DC average value measuring unit that performs processing, a third windowing processing unit that performs a third windowing process on the predetermined number of the sampling data and outputs the third windowing data, and the predetermined number of the first number of the sampling data A DC average processing unit that averages the three window data and outputs it as DC average data, and corrects the attenuation during the third windowing process for the DC average data and outputs it as the DC average value of the measurement target signal Third correction unit A DC average value measurement unit that executes a DC average value measurement process, and the RMS value measurement unit, the AC / DC average value measurement unit, and the DC average value measurement unit include the RMS value measurement process and the AC value measurement process. The DC average value measurement process and the DC average value measurement process are executed in parallel.

  The RMS value measuring device according to claim 7 is the RMS value measuring device according to any one of claims 1 to 6, wherein the sampling data is generated by sampling the measurement target signal at a set sampling period. An A / D converter, a cutout unit that cuts out the predetermined number of sampling data from the sampling data generated by the A / D converter, and an operation for inputting setting data for setting the sampling period And a control unit that sets the sampling period in the A / D conversion unit based on the setting data input by an operation on the operation unit.

  The RMS value measuring device according to claim 8 is the RMS value measuring device according to any one of claims 1 to 6, wherein the sampling target signal is generated by sampling the measurement target signal at a set sampling period. Based on an A / D conversion unit, a cutout unit that cuts out the predetermined number of the sampling data from the sampling data generated by the A / D conversion unit, and a degree of variation in the effective value output from the correction unit And a control unit that determines the sampling period and sets the sampling period in the A / D conversion unit.

  In the effective value measuring apparatus according to claim 1, a windowing process is performed on a predetermined number of sampling data of the measurement target signal to obtain a predetermined number of window data, and a square process is performed on the predetermined number of window data. Unit, first average processing unit, square root calculation unit and first correction unit execute an effective value measurement process to output an effective value of the signal to be measured, and in parallel with this, an absolute value process An AC / DC average value measuring unit having an AC / DC average processing unit and a second correction unit executes an AC / DC average value measurement process and outputs an AC / DC average value of the measurement target signal. Therefore, according to this effective value measuring apparatus, even if the period of the measurement target signal and the sampling period are asynchronous due to the unknown period of the measurement target signal, The RMS value and AC / DC average value can be measured at the same time, while greatly reducing the errors that occur in the RMS value and AC / DC average value due to the fluctuation of the phase of the signal to be measured included in the sampling data. .

  In the effective value measuring apparatus according to claim 2, a windowing process is performed on a predetermined number of sampling data of the measurement target signal to obtain a predetermined number of window data, and a square process is performed on the predetermined number of window data. Unit, first average processing unit, square root calculation unit, and effective value measurement unit having a first correction unit execute the effective value measurement process and output the effective value of the signal to be measured. The DC average value measuring unit having the unit and the third correcting unit executes the DC average value measuring process and outputs the DC average value of the measurement symmetric signal. Therefore, according to this effective value measuring apparatus, even if the period of the measurement target signal and the sampling period are asynchronous due to the unknown period of the measurement target signal, It is possible to simultaneously measure the effective value and the DC average value while greatly reducing an error that occurs in the effective value and the DC average value due to the fluctuation of the phase of the measurement target signal included in the sampling data.

  In the effective value measuring apparatus according to claim 3, a windowing process is performed on a predetermined number of sampling data of the measurement target signal to obtain a predetermined number of window data, and a square process is performed on the predetermined number of window data. Unit, first average processing unit, square root calculation unit and first correction unit execute an effective value measurement process to output an effective value of the signal to be measured, and in parallel with this, an absolute value process An AC / DC average value measurement unit having an AC / DC average processing unit and a second correction unit executes an AC / DC average value measurement process to output an AC / DC average value of the signal to be measured; The DC average value measurement unit having the DC average processing unit and the third correction unit executes the DC average value measurement process and outputs the DC average value of the measurement symmetric signal. Therefore, according to this effective value measuring apparatus, even if the period of the measurement target signal and the sampling period are asynchronous due to the unknown period of the measurement target signal, Effective value, AC / DC average value, and DC average are greatly reduced while reducing errors in RMS value, AC / DC average value, and DC average value due to fluctuations in the phase of the signal to be measured included in the sampling data. Values can be measured simultaneously.

  According to the effective value measuring apparatus of the fourth aspect, similarly to the effective value measuring apparatus of the first aspect, it is included in the predetermined number of sampling data because the period of the measurement target signal is unknown. Even if the waveform of the signal to be measured fluctuates, an error that occurs due to the fluctuation of the phase of the signal to be measured included in the predetermined number of sampling data is provided in the RMS value measurement unit and AC / DC average value measurement unit Since each windowing processing unit can greatly reduce the error, an error that occurs in the effective value and the AC / DC average value due to the change in the phase of the signal to be measured included in the predetermined number of sampling data. The effective value and the AC / DC average value can be measured simultaneously while greatly reducing.

  According to the effective value measuring apparatus according to claim 5, as in the effective value measuring apparatus according to claim 2, it is included in the predetermined number of sampling data due to the unknown period of the signal to be measured. Even if the waveform of the signal to be measured fluctuates, errors that occur due to fluctuations in the phase of the signal to be measured included in the predetermined number of sampling data are provided in the RMS value measurement unit and the DC average value measurement unit. In addition, each windowing processing unit can greatly reduce the error, and the error that occurs in the RMS value and DC average value due to fluctuations in the phase of the signal to be measured included in the predetermined number of sampling data. While being reduced, the effective value and the AC / DC average value can be measured simultaneously.

  According to the effective value measuring apparatus of the sixth aspect, similarly to the effective value measuring apparatus of the third aspect, it is included in the predetermined number of sampling data because the period of the measurement target signal is unknown. Even if the waveform of the signal to be measured fluctuates, errors that occur due to fluctuations in the phase of the signal to be measured included in the predetermined number of sampling data are detected by the effective value measuring unit, the AC / DC average value measuring unit, and the DC Each windowing processing unit provided in the average value measurement unit can greatly reduce the effective value, AC / DC average due to fluctuations in the phase of the signal to be measured included in the predetermined number of sampling data It is possible to simultaneously measure the effective value and the AC / DC average value while greatly reducing errors occurring in the value and the DC average value.

  In the effective value measuring apparatus according to the seventh aspect, the control unit sets the sampling period in the A / D conversion unit based on the setting data input by operating the operation unit. Therefore, according to this effective value measuring apparatus, the sampling period of the A / D conversion unit can be changed by an operation on the operation unit. Therefore, when it is determined that the number of waveforms of the measurement target signal included in the predetermined number of sampling data is small because the effective value of the measurement target signal displayed on the display unit varies, the sampling period of the A / D conversion unit Can be increased to increase the number of waveforms of the signal to be measured, thereby preventing a decrease in measurement accuracy such as an effective value.

  In the effective value measuring apparatus according to the eighth aspect, the control unit determines the sampling period based on the degree of variation in the effective value output from the first correction unit and sets the sampling period in the A / D conversion unit. Therefore, according to the effective value measuring apparatus, when the control unit determines that the number of waveforms of the measurement target signal included in the predetermined number of sampling data is small due to variations in the effective value of the measurement target signal, the control unit The sampling period of the A / D conversion unit can be lengthened to automatically increase the number of waveforms of the measurement target signal included, thereby automatically preventing a decrease in measurement accuracy such as an effective value. .

1 is a configuration diagram of an effective value measuring apparatus 1. FIG. It is a block diagram of the effective value calculating part 5 of FIG. It is a block diagram of the AC / DC average value calculating part 6 of FIG. It is a block diagram of the direct-current average value calculating part 7 of FIG. It is a wave form diagram for demonstrating the windowing process by the windowing process part 4 of FIG. It is a wave form diagram for demonstrating the square process by the square process part 21 of the effective value calculating part 5 of FIG. It is a wave form diagram for demonstrating the filtering process by the filter process part 22 of the effective value calculating part 5 of FIG. It is explanatory drawing which shows the error of the effective value measured with the effective value measuring apparatus 1,1A and the conventional effective value measuring apparatus. It is explanatory drawing which shows the difference | error of the AC / DC average value measured with the effective value measuring apparatus 1,1A and the conventional effective value measuring apparatus. It is explanatory drawing which shows the difference | error of the direct-current average value measured with RMS value measuring device 1,1A and the conventional RMS value measuring device. It is a lineblock diagram of effective value measuring device 1A. It is a block diagram of the effective value calculating part 5A of FIG. It is a block diagram of the AC / DC average value calculating part 6A of FIG. It is a block diagram of the direct-current average value calculating part 7A of FIG. It is a wave form diagram for demonstrating the square process by the square process part 21 of the effective value calculating part 5A of FIG. It is a wave form diagram for demonstrating the filtering process by the filter process part 22 of the effective value calculating part 5A of FIG. It is a wave form diagram for demonstrating the windowing process by the windowing process part 26 of the effective value calculating part 5A of FIG.

  Hereinafter, embodiments of an effective value measuring apparatus will be described with reference to the accompanying drawings.

  First, the configuration of the effective value measuring apparatus 1 will be described with reference to the drawings.

  As shown in FIG. 1, the effective value measuring apparatus 1 includes an A / D conversion unit 2, a data extraction unit 3, a windowing processing unit 4, an effective value calculation unit (effective value measurement unit) 5, and an AC / DC average value calculation unit. (AC / DC average value measuring unit) 6, DC average value calculating unit (DC average value measuring unit) 7, operation unit 8, control unit 9, and display unit 10, and effective value Drms and average of input measurement target signal S 1 The values (the alternating DC average value Dava and the DC average value Davd) can be measured. Here, the AC / DC average value means an average value of DC superimposed alternating current (that is, alternating current on which direct current is superimposed).

  The A / D converter 2 includes an A / D converter and a sampling clock generator (both not shown). In this case, the sampling clock generation unit receives the period data Dt from the control unit 9 and generates a sampling clock at a period specified by the period data Dt. That is, the sampling clock generation unit can change the sampling clock cycle according to the input cycle data Dt. The A / D converter samples the input measurement target signal S1 in synchronization with the sampling clock output from the sampling clock generation unit and outputs sampling data D1 indicating the amplitude. With this configuration, the A / D conversion unit 2 causes the measurement target signal S1 whose cycle (or frequency) and input timing are unknown to be changed to a sampling clock asynchronous with the measurement target signal S1 (with respect to the cycle of the measurement target signal S1). Sampling is performed at a clock with a sufficiently early cycle), and sampling data D1 is output.

  The data cutout unit 3 receives the sampling data D1 and cuts out a predetermined number N (N is an integer) of sampling data D1 designated by the data Dp input from the control unit 9 and outputs it as data D2. In this case, the data cutout unit 3 may be configured to cut out the predetermined number N of sampling data D1 (data D2) in a discontinuous state with the predetermined number N of sampling data D1 (data D2) cut out immediately before. It may be configured to cut out in a state. In this example, the data cutout unit 3 cuts sampling data D1 (data D2) in a continuous state as an example. Further, the predetermined number N specified by the data Dp is defined so as to coincide with the number of correction data for the windowing process stored in advance in the windowing processing unit 4.

  The windowing processing unit 4 uses a predetermined number N (the same number as the input data) of correction data Dc (see FIG. 5) stored in advance for the input predetermined number N of data. A windowing process is executed, and the corrected data is output as window data D3. In this example, the windowing processing unit 4 inputs a predetermined number N of data D2 output from the data cutout unit 3, and executes the windowing processing using the correction data Dc for the windowing processing, thereby correcting the data. The subsequent predetermined number N of data D2 is output as window data D3. As the correction data Dc, data for windowing using a known window function such as a Blackman-Harris window function or a Hanning window function is used.

  For example, as shown in FIG. 2, the effective value calculation unit 5 includes a square processing unit 21, a filter processing unit 22, an average processing unit 23 (first average processing unit), a square root processing unit 24, and a correction unit 25 (first unit). Each time a predetermined number N of window data D3 is input, the effective value Drms of the measurement target signal S1 is calculated and output based on the input window data D3. In this case, the square processor 21 squares the input window data D3 and outputs the squared data D4. The filter processing unit 22 is configured by a low-pass filter (for example, a filter whose cut-off frequency is regulated to several Hz to several tens Hz). The filter processing unit 22 is configured by a digital filter such as an IIR (infinite impulse response) filter or an FIR (finite impulse response) filter, for example, and performs filtering processing to remove ripple components on the input data. Output. In this example, the filter processing unit 22 performs a filtering process on the input squared data D4 and outputs it as new squared data D5.

  The average processing unit 23 inputs a predetermined number N of data, calculates an average thereof, and outputs the average. In this example, the average processing unit 23 inputs a predetermined number N of squared data D5, calculates the average thereof, and outputs it as average data D6 (first average data). As a method for calculating the average, a general average calculation method of dividing the total sum of all input data by the total number of data may be employed, or a moving average method may be employed. The square root processing unit 24 is composed of a square root extractor and calculates and outputs the square root of the input data. In this example, the square root processing unit 24 calculates the square root of the average data D6 and outputs it as the square root data D7.

  The correction unit 25 corrects the attenuation during the windowing process (outputs the data before the attenuation) and outputs the input data (data subjected to the windowing process). In this example, the correction unit 25 corrects the attenuation of the window data D3 with respect to the data D2 (predetermined number N of sampling data D1) during the windowing process in the windowing processing unit 4 with respect to the square root data D7. Output. Thereby, the corrected data output from the correction unit 25 is data indicating the effective value Drms of the measurement target signal S1.

  As shown in FIG. 3, for example, the AC / DC average value calculation unit 6 includes an absolute value calculation unit 31, a filter processing unit 32, an average processing unit 33 (AC / DC average processing unit), and a correction unit 34 (second correction unit). ) And calculates and outputs an AC / DC average value Dava of the measurement target signal S1 based on the input window data D3. In this case, when the window data D3 (when the measurement target signal S1 is an AC signal (including an AC signal having a DC component), the absolute value calculation unit 31 has polarity data (the polarity is as shown in FIG. 5). Is generated), and absolute value data D8 indicating the absolute value is generated and output.

  The filter processing unit 32 is configured by a low-pass filter similar to the filter processing unit 22, and performs a filtering process to remove a ripple component on the input data and outputs the filtered data. In this example, the filter processing unit 32 performs a filtering process on the input absolute value data D8 and outputs it as new absolute value data D9.

  The average processing unit 33 is configured in the same manner as the average processing unit 23, inputs a predetermined number N of data, calculates an average of them, and outputs the average. In this example, the average processing unit 33 inputs a predetermined number N of absolute value data D9, calculates the average thereof, and outputs the average data D10 (AC / DC average data). As a method for calculating the average, as described in the description of the average processing unit 23, a general average calculation method or a moving average method can be employed.

  The correction unit 34 is configured in the same manner as the correction unit 25, and corrects the input data (windowed data) by correcting the attenuation during the windowing process (amplification to amplify the state before attenuation). Go) and output. In this example, the correction unit 34 corrects the attenuation of the window data D3 with respect to the data D2 (predetermined number N of sampling data D1) during the windowing process in the windowing processing unit 4 with respect to the average data D10. Output. Since the AC / DC average value calculation unit 6 includes the absolute value calculation unit 31 as described above, the average data D10 includes not only the DC component included in the window data D3, that is, the measurement target signal S1. AC components are also included. Thus, the corrected data output from the correction unit 34 is data indicating the AC / DC average value Dava of the measurement target signal S1.

  For example, as shown in FIG. 4, the DC average value calculation unit 7 includes a filter processing unit 41, an average processing unit 42 (DC average processing unit), and a correction unit 43 (third correction unit). Based on D3, the DC average value Davd of the measurement target signal S1 is calculated and output. In this case, the filter processing unit 41 is configured by a low-pass filter similar to the filter processing unit 22, and performs a filtering process to remove a ripple component on the input data and outputs the filtered data. In this example, the filter processing unit 41 performs a filtering process on the input window data D3 and outputs the result as new window data D11.

  The average processing unit 42 is configured in the same manner as the average processing unit 23, inputs a predetermined number N of data, calculates an average of them, and outputs the average. In this example, the average processing unit 42 inputs a predetermined number N of window data D11, calculates an average of them, and outputs the average data D12 (DC average data). As a method for calculating the average, as described in the description of the average processing unit 23, a general average calculation method or a moving average method can be employed.

  The correction unit 43 is configured in the same manner as the correction unit 25, and corrects the input data (data subjected to the windowing process) by correcting the attenuation during the windowing process (amplification to amplify the state before the attenuation). Go) and output. In this example, the correction unit 43 corrects the attenuation of the window data D3 with respect to the data D2 (predetermined number N of sampling data D1) during the windowing process in the windowing processing unit 4 with respect to the average data D12. Output. Unlike the AC / DC average value calculation unit 6, the DC average value calculation unit 7 does not include the absolute value calculation unit 31, and therefore the average data D12 is included in the window data D3, that is, the measurement target signal S1. It consists only of DC components. Thus, the corrected data output from the correction unit 43 is data indicating the DC average value Davd of the measurement target signal S1.

  The operation unit 8 includes a selection switch (not shown) that can select setting data Ds for setting the sampling period in the A / D conversion unit 2, and sets the setting data Ds according to the operation content with respect to the selection switch. Output to 9. The control unit 9 includes a CPU and a memory, and executes a sampling cycle setting process for the A / D conversion unit 2 based on the input setting data Ds. The control unit 9 also includes an effective value Drms, an AC / DC average value Dava, and a DC average value Davd (hereinafter collectively referred to as the RMS value calculated by the RMS value calculating unit 5, the AC / DC average value calculating unit 6 and the DC / average value calculating unit 7, respectively. Display process of displaying “effective value Drms etc.” on the display unit 10 is also executed. The display unit 10 includes a monitor device such as a liquid crystal display, for example, and displays the effective value Drms and the like output from the control unit 9 numerically. Note that the display unit 10 may be configured by a printing device such as a printer instead of the monitor device.

  Next, an operation of measuring the effective value Drms and the like for the measurement target signal S1 by the effective value measuring apparatus 1 will be described.

  In the effective value measuring apparatus 1, when the operation unit 8 is operated in the operating state, the operation unit 8 outputs setting data Ds corresponding to the operation content to the control unit 9 as shown in FIG. In this example, the operation unit 8 outputs period data Dt indicating a sampling period to the control unit 9 as the setting data Ds. The control unit 9 inputs the cycle data Dt and outputs the cycle data Dt to the A / D conversion unit 2 (by executing the sampling cycle setting process), thereby sampling the A / D conversion unit 2. Set the cycle. Further, the control unit 9 sets the number of sampling data D1 to be cut out to a predetermined number N by outputting the data Dp to the data cutout unit 3.

  As a result, the A / D conversion unit 2 starts sampling the measurement target signal S1 at the set sampling period and starts outputting the sampling data D1 to the data extraction unit 3. Further, as shown in FIG. 5, the data cutout unit 3 cuts out (divides) the sampling data D1 of the measurement target signal S1 by a predetermined number N and sequentially outputs it as data D2. In this case, the cut out data D2 is data on the divided waveform S2 of the measurement target signal S1.

  Further, the windowing processing unit 4 sequentially inputs the data D2 (predetermined number N of sampling data D1) output from the data extraction unit 3, and uses the correction data Dc for windowing processing to the data D2 A windowing process is executed, and the corrected data D2 is output as window data D3 (data indicating the waveform S3). In FIG. 5 to FIG. 7, in order to facilitate understanding of the invention, the timings of starting and ending the cutout of the data D2 are shown in a state of being synchronized (matched) with the zero cross point of the measurement target signal S1. Actually, the cycle of the measurement target signal S1 is unknown, and the sampling cycle of the A / D converter 2 and the cycle of the measurement target signal S1 are asynchronous. It does not necessarily coincide with the zero cross point of the target signal S1.

  Further, the effective value calculation unit 5, the AC / DC average value calculation unit 6 and the DC average value calculation unit 7 simultaneously calculate the effective value Drms, the AC / DC average value Dava and the DC average value Davd based on the window data D3. Start (in parallel).

  Specifically, in the effective value calculation unit 5, the square processing unit 21 first squares a predetermined number N of window data D3 and outputs square data D4 representing the waveform S4 shown in FIG. Next, the filter processing unit 22 removes the ripple component included in the predetermined number N of square data D4, and outputs data representing the waveform S5 shown in FIG. 7 as new square data D5. Subsequently, as shown in FIG. 2, the average processing unit 23 calculates the average data D6 by averaging a predetermined number N of squared data D5, and the square root processing unit 24 calculates the square root of the average data D6. , And output as square root data D7. Finally, the correction unit 25 performs a process of correcting the attenuation during the windowing process on the square root data D7 and outputs the result to the control unit 9 as the effective value Drms of the measurement target signal S1.

  Further, in the AC / DC average value calculation unit 6, first, the absolute value calculation unit 31 generates and outputs absolute value data D8 for a predetermined number N of window data D3. Next, the filter processing unit 32 removes the ripple component included in the predetermined number N of absolute value data D8 and outputs the new absolute value data D9. Subsequently, the average processing unit 33 averages a predetermined number N of absolute value data D9 to calculate average data D10. Finally, the correction unit 25 calculates the attenuation during the windowing process for the average data D10. The correction process is performed, and the result is output to the control unit 9 as the AC / DC average value Dava of the measurement target signal S1.

  Further, in the DC average value calculation unit 7, first, the filter processing unit 41 removes the ripple component included in the predetermined number N of window data D3 and outputs the new window data D11. Subsequently, the average processing unit 42 averages a predetermined number N of window data D11 to calculate the average data D12. Finally, the correction unit 43 corrects the attenuation during the windowing process for the average data D12. To the control unit 9 as a DC average value Davd of the measurement target signal S1.

  In this case, the control unit 9 determines the effective value Drms input from the effective value calculation unit 5, the AC / DC average value Dava input from the AC / DC average value calculation unit 6, and the DC average value Davd input from the DC average value calculation unit 7. Are simultaneously displayed on the display unit 10. Thereby, the measurement of the effective value Drms and the like for the measurement target signal S1 by the effective value measuring apparatus 1 is completed. Since the effective value calculation unit 5, the AC / DC average value calculation unit 6 and the DC average value calculation unit 7 repeatedly execute the calculation of the effective value Drms and the like and output it to the control unit 9, the control unit 9 Each time a new effective value Drms or the like is input from the calculation unit 5, the AC / DC average value calculation unit 6, and the DC average value calculation unit 7, it is displayed on the display unit 10. Therefore, the latest effective value Drms and the like are displayed on the display unit 10.

  As described above, in the effective value measuring apparatus 1, the windowing process is performed on the cut-out predetermined number N of sampling data D1 (data D2) to obtain window data D3. After the effective value calculation unit 5 performs basic processing for calculating effective values such as square processing, filtering processing, average processing, and square root processing, the square root data D7 obtained by these processing is subjected to windowing processing. The effective value Drms of the measurement target signal S1 is calculated by performing a process of correcting the amount of attenuation. In addition, the AC / DC average value calculation unit 6 performs an exchange of absolute value calculation processing, filtering processing, and average processing on the window data D3 in parallel (simultaneously) with the calculation operation of the effective value Drms by the effective value calculation unit 5. After performing the basic processing for calculating the DC average value, the average data D10 obtained by these processings is subjected to processing for correcting the attenuation during the windowing processing, and the measurement target signal S1 is exchanged. The DC average value Dava is calculated. In addition, the DC average value calculation unit 7 also calculates the AC average value of the filtering process and the average process for the window data D3 in parallel (simultaneously) with the calculation operation of the effective value Drms by the effective value calculation unit 5. After performing the basic processing, the average data 12 obtained by these processings is subjected to processing for correcting the attenuation during the windowing processing, and the DC average value Davd of the measurement target signal S1 is calculated. .

  Therefore, according to the effective value measuring apparatus 1, the cycle of the measurement target signal S1 and the sampling cycle in the A / D converter 2 are asynchronous because the cycle of the measurement target signal S1 is unknown. However, due to the variation in the phase of the measurement target signal S1 included in the predetermined number N of sampling data D1 due to the windowing process (in other words, due to the change in the cut-out position with respect to the measurement target signal S1). Errors that occur in the effective value Drms and the like can be greatly reduced. In addition, according to the effective value measuring apparatus 1, the effective value calculation unit 5, the AC / DC average value calculation unit 6 and the DC average value calculation unit 7 execute the calculation operation in parallel (simultaneously). Can be measured simultaneously.

  Next, experimental results (simulation results) about the calculation accuracy (measurement accuracy) of the effective value Drms and the like by the effective value measuring apparatus 1 are shown in FIGS. According to FIG. 8, the error of the effective value measured by the conventional effective value measuring apparatus that does not execute the windowing process is about 3.6%, whereas the error of the effective value measuring apparatus 1 is 0. It is greatly reduced to less than 01%. Further, according to FIG. 9, when the measurement target signal S1 is an AC signal (for example, AC 100 volts), the error of the AC / DC average value measured by a conventional effective value measuring apparatus that does not execute the windowing process is about Whereas it is 4.9%, in the effective value measuring apparatus 1, the error is greatly reduced to about 0.015%. Further, even when the measurement target signal S1 is an AC / DC signal (for example, a signal in which DC 100V is superimposed on AC 100V), the AC / DC average value measured by a conventional effective value measuring apparatus that does not perform windowing processing is used. Whereas the error is about 23%, in the effective value measuring apparatus 1, the error is greatly reduced to about 1.8%. Further, according to FIG. 10, when the measurement target signal S1 is an AC signal (a signal obtained by superimposing DC100 volts on AC100 volts as an example), the measurement is performed by a conventional effective value measuring apparatus that does not perform windowing processing. While the error of the DC average value is about 23%, in the effective value measuring apparatus 1, the error is greatly reduced to about 1.8%.

  In the effective value measuring apparatus 1, the sampling cycle of the A / D conversion unit 2 can be changed by an operation on the operation unit 8. Therefore, according to the effective value measuring apparatus 1, a predetermined number N of sampling data D1 (data D2) cut out due to variations in numerical values such as the effective value Drms of the measurement target signal S1 displayed on the display unit 10. ), The number of waveforms of the measurement target signal S1 included in the predetermined number N of extracted sampling data D1 may be increased by increasing the sampling period. This can prevent a decrease in measurement accuracy such as the effective value Drms.

  On the contrary, when the numerical value such as the effective value Drms of the measurement target signal S1 displayed on the display unit 10 hardly varies, the waveform of the measurement target signal S1 included in the predetermined number N of extracted sampling data D1. It is also possible to shorten the calculation cycle of the effective value Drms and the like by reducing the number. Therefore, by shortening the sampling cycle and reducing the number of waveforms of the measurement target signal S1 included in the predetermined number N of the extracted sampling data D1, the calculation cycle is shortened while maintaining the measurement accuracy of the effective value Drms and the like. (The update cycle of the effective value Drms and the like can be advanced).

  The configuration of the effective value measuring apparatus is not limited to the above configuration. For example, in the above-described effective value measuring apparatus 1, the effective value calculation unit 5, the AC / DC average value calculation unit 6, and the DC average value calculation unit 7 are all based on the common window data D3 after the windowing process. Although a configuration for performing a calculation such as Drms is employed, a configuration in which a windowing process is performed in each of the effective value calculation unit 5, the AC / DC average value calculation unit 6, and the DC average value calculation unit 7 may be employed. Hereinafter, an effective value measuring apparatus 1A having this configuration will be described. In addition, about the structure same as the effective value measuring apparatus 1, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  As shown in FIG. 11, the effective value measuring apparatus 1A includes an effective value calculation unit 5A instead of the effective value calculation unit 5, and includes an AC / DC average value calculation unit 6A instead of the AC / DC average value calculation unit 6. Although it is different from the effective value measuring apparatus 1 in that a DC average value calculation unit 7A is provided instead of the DC average value calculation unit 7, the other configurations are the same.

  Specifically, as shown in FIG. 12, the effective value calculation unit 5A is similar to the effective value calculation unit 5 of the effective value measuring apparatus 1, and the square processing unit 21, the filter processing unit 22, the average processing unit 23, In addition to the square root processing unit 24 and the correction unit 25, the windowing processing unit 26 (first windowing processing unit) is further provided. In the effective value measuring apparatus 1, as described above, the windowing processing unit 4 includes: Whereas the effective value calculation unit 5A is arranged before the square processing unit 21 and the filter processing unit 22 constituting the effective value calculation unit 5, the windowing processing unit 26 includes the square processing unit 21 and the filter processing. Arranged downstream of the unit 22 (between the filter processing unit 22 and the average processing unit 23).

  Further, as shown in FIG. 13, the AC / DC average value calculation unit 6 </ b> A is similar to the AC / DC average value calculation unit 6 of the effective value measuring apparatus 1, and includes an absolute value calculation unit 31, a filter processing unit 32, and an average processing unit. 33 and the correction unit 34, and further includes a windowing processing unit 35 (second windowing processing unit). As described above, in the effective value measuring apparatus 1, the windowing processing unit 4 includes the AC / DC average. Whereas the absolute value calculation unit 31 and the filter processing unit 32 constituting the value calculation unit 6 are arranged in the previous stage, in the AC / DC average value calculation unit 6A, the windowing processing unit 35 is connected to the filter processing unit 32. It is arranged in the subsequent stage (between the filter processing unit 32 and the average processing unit 33).

  Further, as shown in FIG. 14, the DC average value calculation unit 7A includes a filter processing unit 41, an average processing unit 42, and a correction unit 43 in the same manner as the DC average value calculation unit 7 of the effective value measuring apparatus 1. The effective value measuring apparatus 1 further includes a windowing processing unit 44 (third windowing processing unit). As described above, the windowing processing unit 4 performs the filter processing that constitutes the DC average value calculation unit 7. In the DC average value calculation unit 7A, the windowing processing unit 44 is arranged downstream of the filter processing unit 41 (between the filter processing unit 41 and the average processing unit 42). It is arranged.

  With this configuration, also in the effective value measuring apparatus 1A, the effective value calculation unit 5A, the AC / DC average value calculation unit 6A, and the DC average value calculation unit 7A have the data D2 about the measurement target signal S1 output from the data cutout unit 3. Are simultaneously calculated, and an effective value Drms and the like for the measurement target signal S1 are simultaneously calculated and output to the control unit 9.

  Specifically, in the effective value calculation unit 5A, the square processing unit 21 performs a square process on the data D2 (predetermined number N of sampling data D1) output from the data extraction unit 3, and is shown in FIG. A predetermined number N of squared data D21 representing the waveform S21 is output, and the filter processing unit 22 performs a filtering process on the squared data D21 to generate a new predetermined number N of squared data representing the waveform S22 shown in FIG. D22 is output. Next, the windowing processing unit 26 performs a windowing process on the squared data D22 using the correction data Dc for the windowing process, and a predetermined number N of window data representing the waveform S23 shown in FIG. D23 (first window data) is output. Subsequently, the average processing unit 23 averages the predetermined number N of window data D23 and outputs the averaged data as one average data D24 as shown in FIG. In the subsequent stage, the operation is performed in the same manner as the effective value calculation unit 5, the square root processing unit 24 calculates the square root of the average data D24 and outputs it as the square root data D25, and the correction unit 25 outputs the square root data D25. A process for correcting the attenuation during the windowing process is performed and output to the control unit 9 as the effective value Drms of the measurement target signal S1.

  In the AC / DC average value calculation unit 6A, first, the absolute value calculation unit 31 generates and outputs absolute value data D26 for a predetermined number N of data D2. Next, the filter processing unit 32 removes a ripple component included in the predetermined number N of absolute value data D26 and outputs the new absolute value data D27. Subsequently, the windowing processing unit 35 performs a windowing process on the absolute value data D27 using the correction data Dc for the windowing process to obtain a predetermined number N of window data D28 (second window data). ) Is output. Next, the average processing unit 33 averages a predetermined number N of window data D28 to calculate average data D29. Finally, the correction unit 34 corrects the attenuation during the windowing process for the average data D29. Processing is performed and output to the control unit 9 as the AC / DC average value Dava of the measurement target signal S1.

  In DC average value calculation unit 7A, first, filter processing unit 41 removes a ripple component included in a predetermined number N of data D2 and outputs the result as new data D30. Next, the windowing processing unit 44 performs a windowing process on the data D30 using the correction data Dc for the windowing process, and outputs a predetermined number N of window data D31 (third window data). To do. Subsequently, the average processing unit 42 calculates the average data D32 by averaging the predetermined number N of window data D31. Finally, the correction unit 43 corrects the attenuation during the windowing process for the average data D32. To the control unit 9 as a DC average value Davd of the measurement target signal S1.

  As described above, in the effective value measuring apparatus 1A, since the windowing process is executed for each calculation of the effective value Drms and the like, the measurement target signal S1 and the measurement target signal S1 are Even if the sampling period in the A / D conversion unit 2 is asynchronous, the phase of the measurement target signal S1 included in the predetermined number N of sampling data D1 varies (in other words, the measurement target signal S1 The generated error (due to fluctuations in the cutout position with respect to) can be greatly reduced by the windowing process. The experimental results (simulation results) about the calculation accuracy (measurement accuracy) of the effective value Drms and the like by the effective value measuring apparatus 1A are shown in FIGS.

  According to FIG. 8, the error of the effective value measured by the conventional effective value measuring apparatus that does not execute the windowing process is about 3.6%, whereas the error of the effective value measuring apparatus 1A is 0. It is greatly reduced to about 01%. Further, according to FIG. 9, when the measurement target signal S1 is an AC signal (for example, AC 100 volts), the error of the AC / DC average value measured by a conventional effective value measuring apparatus that does not execute the windowing process is about Whereas it is 4.9%, in the effective value measuring apparatus 1A, the error is greatly reduced to about 0.015%. Also, when the measurement target signal S1 is an AC / DC signal (for example, a signal in which DC 100V is superimposed on AC 100V), the AC / DC average value measured by a conventional effective value measuring apparatus that does not perform windowing processing is used. While the error is about 23%, the error is significantly reduced to about 1.8% in the effective value measuring apparatus 1A. Further, according to FIG. 10, when the measurement target signal S1 is an AC signal (a signal obtained by superimposing DC100 volts on AC100 volts as an example), the signal is measured by a conventional effective value measuring apparatus that does not perform windowing processing. The error of the DC average value is about 23%, whereas in the effective value measuring apparatus 1A, the error is greatly reduced to about 1.8%.

  In addition, since the A / D conversion unit 2, the data extraction unit 3, the operation unit 8, and the control unit 9 of the effective value measuring apparatus 1A are the same as those in the effective value measuring apparatus 1, the effective value measuring apparatus 1A also has the same configuration. Similar to the effective value measuring apparatus 1, the sampling period of the A / D conversion unit 2 can be changed by an operation on the operation unit 8. Therefore, the effective value measuring apparatus 1A also determines that the number of waveforms of the measurement target signal S1 included in the predetermined number N of extracted sampling data D1 (data D2) is the same as the effective value measuring apparatus 1 described above. In some cases, the sampling period can be lengthened to increase the number of waveforms of the measurement target signal S1 included in the cut-out predetermined number N of sampling data D1, so that the measurement accuracy can be improved.

  In the effective value measuring apparatus 1A, the configuration in which the filter processing unit 22 is disposed upstream of the windowing processing unit 26 in the effective value calculating unit 5A has been described above. However, the filter processing unit is provided downstream of the windowing processing unit 26. In this case, even when this configuration is adopted, the calculation accuracy of the effective value Drms can be improved.

  Further, in the above-described effective value measuring devices 1 and 1A, the effective value calculation units 5 and 5A, the AC / DC average value calculation units 6 and 6A, and the DC average value calculation units 7 and 7A include the filter processing units 22, 32, 41 is employed. However, when the ripple component included in the sampling data D1 is small, each of the effective value calculation units 5, 5A, AC and DC is excluded without including the filter processing units 22, 32, 41. The average value calculation units 6 and 6A and the direct current average value calculation units 7 and 7A can also be configured. Thereby, the apparatus configuration can be simplified.

  In the above-described effective value measuring apparatuses 1 and 1A, a configuration is adopted in which the sampling period of the A / D conversion unit 2 is changed by an operation on the operation unit 8. However, the control unit 9 inputs the effective value Drms. Is determined, and at least one of the variation of the AC / DC average value Dava and the variation of the DC average value Davd is determined, and the sampling period is determined based on the determination result (variation). Thus, it is possible to adopt a configuration (in this configuration, the operation unit 8 is not necessary) that is changed (lengthened or shortened).

  In this configuration, for example, when the degree of variation in the effective value Drms of the measurement target signal S1 is large (for example, when it varies beyond a preset allowable range), the control unit 9 has a predetermined number N of cut outs. By determining that the number of waveforms of the measurement target signal S1 included in the sampling data D1 is small and changing the period data Dt, the sampling period of the A / D converter 2 is lengthened. According to this configuration, when the degree of variation in the effective value Drms is large, the number of waveforms of the measurement target signal S1 included in the predetermined number N of sampling data D1 can be automatically increased, and thereby the effective value Drms. Thus, it is possible to automatically prevent a decrease in the measurement accuracy.

  Further, the data cutout unit 3 cuts out the sampling data D1 input from the A / D conversion unit 2 by a predetermined number N specified by the data Dp input from the control unit 9, and is constituted by a predetermined number of sampling data D1 The data D2 is divided and sequentially output, and the average value processing units 5 and 5A, the AC / DC average value calculation units 6 and 6A, and the DC average value calculation units 7 and 7A that are arranged in the subsequent stages are average processing units 23 and 33, Although the configuration (batch processing configuration) for executing each process every time the constituent elements up to 42 input a predetermined number N of all data has been described above, other configurations can be adopted.

  Specifically, the data cutout unit 3 cuts out and outputs a predetermined number N of the sampling data D1 input from the A / D conversion unit 2 in real time for each data, and outputs the average processing units 23 and 33 arranged in the subsequent stages. , 42 are inputted in real time one by one while each processing is sequentially executed and outputted for one data, and each average processing unit 23, 33, 42 inputs one data. Configuration that outputs average data D6, D10, D12, D24, D29, D32 when calculating the average of a predetermined number N of data while calculating the average with the data already input (average processing unit 23, It is also possible to employ a configuration in which each of the components up to 33 and 42 is processed in real time. According to this configuration, the processing time from the data extraction unit 3 to the average processing units 23, 33, and 42 can be shortened, and thus the measurement time for the effective value Drms and the like can be shortened.

  Further, in the above-described effective value measuring apparatuses 1 and 1A, the number of correction data for the windowing process stored in advance in each windowing processing unit 4, 26, 35, 44 is fixed (fixed). The multiplying processing units 4, 26, 35, and 44 may store correction data for a plurality of windowing processes having different numbers of data, and can arbitrarily select one of them. Thereby, in the effective value measuring apparatuses 1 and 1A in which the number of correction data is fixed (fixed), the number of sampling data D1 cut out by the data cutout unit 3 is also a predetermined number N (fixed) that is the same as the number of correction data. Therefore, in order to increase the number of waveforms of the measurement target signal S1 included in the predetermined number N of extracted sampling data D1, it is necessary to lengthen the sampling period.

  However, in the effective value measuring apparatus configured to be able to arbitrarily select one of a plurality of correction data (correction data having different numbers of data) for the windowing process, the sampling period is fixed and the windowing is performed. The correction data having a large number of data is selected as the correction data for the windowing processing in the processing units 4, 26, 35, and 44, and the predetermined number N of the sampling data D1 cut out by the data cutout unit 3 corresponding thereto is also selected. By increasing the number, the number of waveforms of the measurement target signal S1 included in the sampling data D1 (data D2) cut out by the data cutout unit 3 can be increased. Conversely, the sampling data selected by the data cutout unit 3 corresponding to the correction data having a small number of data is selected as the correction data for the windowing processing in the windowing processing units 4, 26, 35, and 44. By reducing the predetermined number N of the data D1, the number of waveforms of the measurement target signal S1 included in the sampling data D1 (data D2) cut out by the data cutout unit 3 can be reduced. Therefore, according to the effective value measuring apparatus employing this configuration, the number of waveforms of the measurement target signal S1 included in the sampling data D1 (data D2) extracted by the data extraction unit 3 can be increased or decreased as necessary.

  Further, the effective value measuring devices 1 and 1A employ a configuration for simultaneously measuring the effective value Drms and the like, but the effective value measuring device 1 includes an effective value calculating unit 5 and an AC / DC average value calculating unit 6. The effective value measuring device 1A includes the effective value calculation unit 5A and the AC / DC average value calculation unit 6A, and does not include the DC average value calculation unit 7A. Only the Drms and the AC / DC average value Dava can be measured. Further, the effective value measuring apparatus 1 includes the effective value calculating unit 5 and the DC average value calculating unit 7, and does not include the AC / DC average value calculating unit 6. In the effective value measuring apparatus 1A, the effective value calculating unit 5A. Further, as a configuration including the DC average value calculation unit 7A and not including the AC / DC average value calculation unit 6A, only the effective value Drms and the DC average value Davd may be measured.

DESCRIPTION OF SYMBOLS 1,1A RMS value measuring device 2 A / D conversion part 3 Data extraction part 4,26,35,44 Windowing part 5,5A RMS value calculation part 6,6A AC / DC average value calculation part 7,7A DC average value Arithmetic unit 21 Square processing unit 23, 33, 42 Average processing unit 24 Square root processing unit 25, 34, 43 Correction unit D1 Sampling data D2 data D3, D23, D28, D31 Window data D4, D21 Squared data D6, D10, D12, D24, D29, D32 Average data D25 Square root data Dc Correction data Dava AC / DC average value Davd DC average value Drms RMS S1 Signal to be measured

Claims (8)

A windowing processing unit that performs windowing on a predetermined number of sampling data for the measurement target signal and outputs the result as window data;
A square processing unit that squares the predetermined number of the window data and outputs the squared data, a first average processing unit that averages the predetermined number of the squared data and outputs the average data, and outputs the first average data. A square root calculation unit that calculates a square root and outputs the square root data, and a first correction unit that corrects an attenuation during the windowing process and outputs the square root data as an effective value of the measurement target signal. An effective value measuring unit for executing an effective value measuring process,
An absolute value processing unit that calculates an absolute value of the predetermined number of the window data and outputs the absolute value data, an AC / DC average processing unit that averages the predetermined number of the absolute value data and outputs the average value as AC / DC average data, And a second correction unit that corrects the attenuation during the windowing process with respect to the AC / DC average data and outputs the AC / DC average value of the measurement target signal to execute the AC / DC average value measurement process. An AC / DC average value measuring unit,
The effective value measuring device in which the effective value measuring unit and the AC / DC average value measuring unit execute the effective value measuring process and the AC / DC average value measuring process in parallel. A windowing processing unit that performs windowing on a predetermined number of sampling data for the measurement target signal and outputs the result as window data;
A square processing unit that squares the predetermined number of the window data and outputs the squared data, a first average processing unit that averages the predetermined number of the squared data and outputs the average data, and outputs the first average data. A square root calculation unit that calculates a square root and outputs the square root data, and a first correction unit that corrects an attenuation during the windowing process and outputs the square root data as an effective value of the measurement target signal. An effective value measuring unit for executing an effective value measuring process,
A DC average processing unit that averages the predetermined number of the window data and outputs it as DC average data, and corrects the attenuation during the windowing process for the DC average data and corrects the DC average value of the signal to be measured. A DC average value measurement unit that has a third correction unit that outputs as a DC average value measurement process,
The effective value measuring device in which the effective value measuring unit and the DC average value measuring unit execute the effective value measuring process and the DC average value measuring process in parallel. A windowing processing unit that performs windowing on a predetermined number of sampling data for the measurement target signal and outputs the result as window data;
A square processing unit that squares the predetermined number of the window data and outputs the squared data, a first average processing unit that averages the predetermined number of the squared data and outputs the average data, and outputs the first average data. A square root calculation unit that calculates a square root and outputs the square root data, and a first correction unit that corrects an attenuation during the windowing process and outputs the square root data as an effective value of the measurement target signal. An effective value measuring unit for executing an effective value measuring process,
An absolute value processing unit that calculates an absolute value of the predetermined number of the window data and outputs the absolute value data, an AC / DC average processing unit that averages the predetermined number of the absolute value data and outputs the average value as AC / DC average data, And a second correction unit that corrects the attenuation during the windowing process with respect to the AC / DC average data and outputs the AC / DC average value of the measurement target signal to execute the AC / DC average value measurement process. AC / DC average value measurement unit,
A DC average processing unit that averages the predetermined number of the window data and outputs it as DC average data, and corrects the attenuation during the windowing process for the DC average data and corrects the DC average value of the signal to be measured. A DC average value measurement unit that has a third correction unit that outputs as a DC average value measurement process,
The effective value measurement unit, the AC / DC average value measurement unit, and the DC average value measurement unit execute the RMS value measurement process, the AC / DC average value measurement process, and the DC average value measurement process in parallel. measuring device. A square processing unit that squares a predetermined number of sampling data for the measurement target signal and outputs the squared data as a square data, and performs a first windowing process on the predetermined number of squared data and outputs the first window data as a first window data. A windowing processing unit, a first average processing unit that averages the predetermined number of the first window data and outputs the first average data, and calculates a square root of the first average data and outputs the square root data as square root data , And a first correction unit that corrects the attenuation during the first windowing process with respect to the square root data and outputs it as an effective value of the signal to be measured, and performs an effective value measurement process to execute an effective value measurement process And
An absolute value processing unit that calculates an absolute value of the predetermined number of the sampling data and outputs the absolute value data, and performs a second windowing process on the predetermined number of the absolute value data and outputs it as second window data A second windowing processing unit, an AC / DC average processing unit that averages the predetermined number of the second window data and outputs the result as AC / DC average data, and the second windowing process for the AC / DC average data An AC / DC average value measuring unit that performs an AC / DC average value measurement process and has a second correction unit that corrects the attenuation of the signal and outputs the AC / DC average value of the measurement target signal.
The effective value measuring device in which the effective value measuring unit and the AC / DC average value measuring unit execute the effective value measuring process and the AC / DC average value measuring process in parallel. A square processing unit that squares a predetermined number of sampling data for the measurement target signal and outputs the squared data as a square data, and performs a first windowing process on the predetermined number of squared data and outputs the first window data as a first window data. A windowing processing unit, a first average processing unit that averages the predetermined number of the first window data and outputs the first average data, and calculates a square root of the first average data and outputs the square root data as square root data , And a first correction unit that corrects the attenuation during the first windowing process with respect to the square root data and outputs it as an effective value of the signal to be measured, and performs an effective value measurement process to execute an effective value measurement process And
A third windowing processing unit that performs a third windowing process on the predetermined number of the sampling data and outputs the result as third window data, averages the predetermined number of the third window data, and outputs the averaged DC data. A DC average processing unit, and a third correction unit that corrects the attenuation during the third windowing process for the DC average data and outputs it as a DC average value of the signal to be measured. A DC average value measurement unit for executing measurement processing,
The effective value measuring device in which the effective value measuring unit and the DC average value measuring unit execute the effective value measuring process and the DC average value measuring process in parallel. A square processing unit that squares a predetermined number of sampling data for the measurement target signal and outputs the squared data as a square data, and performs a first windowing process on the predetermined number of squared data and outputs the first window data as a first window data A windowing processing unit, a first average processing unit that averages the predetermined number of the first window data and outputs the first average data, and calculates a square root of the first average data and outputs the square root data as square root data , And a first correction unit that corrects the attenuation during the first windowing process with respect to the square root data and outputs it as an effective value of the signal to be measured, and performs an effective value measurement process to execute an effective value measurement process And
An absolute value processing unit that calculates an absolute value of the predetermined number of the sampling data and outputs the absolute value data, and performs a second windowing process on the predetermined number of the absolute value data and outputs it as second window data A second windowing processing unit, an AC / DC average processing unit that averages the predetermined number of the second window data and outputs the result as AC / DC average data, and the second windowing process for the AC / DC average data An AC / DC average value measurement unit that performs an AC / DC average value measurement process by having a second correction unit that corrects the attenuation of the signal and outputs the AC / DC average value of the measurement target signal;
A third windowing processing unit that performs a third windowing process on the predetermined number of the sampling data and outputs the result as third window data, averages the predetermined number of the third window data, and outputs the averaged DC data. A DC average processing unit, and a third correction unit that corrects the attenuation during the third windowing process for the DC average data and outputs it as a DC average value of the signal to be measured. A DC average value measurement unit for executing measurement processing,
The effective value measurement unit, the AC / DC average value measurement unit, and the DC average value measurement unit execute the RMS value measurement process, the AC / DC average value measurement process, and the DC average value measurement process in parallel. measuring device. An A / D converter that samples the measurement target signal at a set sampling period and generates the sampling data;
A cutout unit that cuts out the predetermined number of sampling data from the sampling data generated by the A / D conversion unit;
An operation unit for inputting setting data for setting the sampling period;
The effective value measurement according to claim 1, further comprising: a control unit configured to set the sampling period in the A / D conversion unit based on the setting data input by an operation on the operation unit. apparatus. An A / D converter that samples the measurement target signal at a set sampling period and generates the sampling data;
A cutout unit that cuts out the predetermined number of sampling data from the sampling data generated by the A / D conversion unit;
The control unit according to claim 1, further comprising: a control unit that determines the sampling period based on a degree of variation in the effective value output from the correction unit and sets the sampling period in the A / D conversion unit. RMS measurement device.

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