JPS60244868A - Multielement arithmetic measuring method of alternating current signal - Google Patents

Abstract

PURPOSE:To allow even a general operational element to perform sufficiently processing by dividing the time of an optional period and reading time-division data continuously, then calculating respective sampling data at a time to considerably prolong a data processing time. CONSTITUTION:Respective inputs in an optional period of an AC voltage and current signal input waveform are time-divided into numers of sampling sections with the same time limit and respective time-division sampling data are read by sample holding circuits 14 and 15 successively. Read results are stored in a memory part 19 at every time, time-division identical-time-limit sampling data on the voltages and currents of active power and apparent power are processed mutually by an arithmetic processor 18, and arithmetic results are totalized and outputted as arithmetic measurement data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for measuring solutes in alternating current signals, and is intended to measure alternating current signals with a simple configuration and with high accuracy.

The configuration of a conventional example and its problems The case of measuring the voltage, current, and active and apparent power of an AC signal will be described.

When the instantaneous values and periods of the voltage and current of the input signals are v, i, and T, respectively, the electrical quantities are as follows.First, the configuration of the conventional example will be explained with reference to FIG. In the figure, 1, 2
are current and voltage signal input terminals, 3 is a digital output terminal for measured values, and 4, 5, and 6.7 are current and voltage signal input terminals, respectively.
Active power.

It is a voltage and apparent power converter, and the above (
The results of analog calculations of equations 1) to (4) are converted into DC output and output. Numeral 8 is a multiplexer which receives a plurality of inputs according to instructions from the arithmetic processing unit 10.

One of W, V, and vA is selected and output to the A/D converter 9. The arithmetic processing unit 10 controls the entire measuring device, and is responsible for switching the measuring circuit, issuing measurement commands to the A/D converter,
Reads the measurement results and outputs the data to the output terminal.

As described above, since one converter is provided for each measurement item, when there are many measurement items, the device becomes large and expensive.Objective of the InventionThe present invention solves these conventional drawbacks. The purpose is to measure AC signals with a simple configuration and with high accuracy.

Structure of the Invention As a structure for this purpose, the present invention includes a sample and hold circuit, an A/D converter, a multiplexer, a memory section, an arithmetic processing unit, and an output section. Each input is time-divided in the same time period in the sampling period, each time-division sampling data is sequentially read, and the reading result is stored in the memory unit each time.
After that, the memory section divides the voltage for each time-division sampling data.

The current is used as a single input, and the active power and apparent power are calculated using the same time-division sampling data of voltage and current, and the calculation results are then aggregated and the results are output as calculated measurement data. It is something.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

In the figure, 11 and 12 are current and voltage signal input terminals, respectively, and 13 is a measured value output terminal.

14.15 is a sampling period (τ/N) unit for sampling the instantaneous value of the AC signal, and 18
1 is an arithmetic processing unit that has a function of controlling the entire measuring device.O19 is a memory unit that stores each measurement data of each sampling period.

The operation will be explained below with reference to FIGS. 3 to 5. In FIG. 3, a) shows a current input waveform, and b) shows a voltage input waveform. When the period τ of current and voltage signal input is divided equally into N sections, the length of one section is τA,
Among these sections, the sampling value of the current n-th section is the finger, vn.

FIG. 4 is a timing explanatory diagram showing the operation order of each part within a time-divided interval, in which (1) is a time-divided interval, and (2) is sampling measurement of i, v instantaneous values for each time division.
The t1 time period is measured by a sampling command given to the sample hold circuit from the arithmetic processing unit. (3) is the output of the sample hold circuit, and the t2 time sample value is held. (Kiku is a sampling value read command to read the output of the above sample hold circuit by the arithmetic processing unit through the multiplexer and A/D converter during time t2, and (5) is the sampling value read in the above to the designated address of the memory section each time. This is the timing of memory operation to store data.

As explained above, the first step is to time-divide the voltage and current equally over an arbitrary period, and store the time-divided sampling value data individually in the memory section. These tasks are performed in the T1 time period shown in the explanatory diagram. In FIG. 5, T1 is shown as one cycle, and although T1 will be explained as one cycle in the following embodiment, it is actually better to use a plurality of arbitrary cycles.

Subsequently, in the T2 time period shown in FIG. 5, the following numerical calculations are performed from all the sampled value memory data.

2) I’=Σin2 (″) -1 3) W’: Σ1n-vn (cumulative product) n=1 4) V person' = Jin - Vn 1 Next, aggregation calculations are performed using the following formula.

5)''j--Bow 1 e) I =, /Teman7) W2W'/Ns) VA = MA'/N Then, this result is output in the T5 time period.

The calculation results are T, which is approximate to equations 1), 2), 3), and 4).

W, MA can be set. Here, by increasing the number of divisions N and by appropriately selecting the measurement period, highly accurate sampling measurement can be achieved.

It should be noted that the above-mentioned arithmetic expression shows one example, and by further increasing the number of inputs, it becomes possible to measure a polyphase circuit as well.

Effects of the Invention As detailed above, the present invention can time-divide an arbitrary period, read the time-divided data continuously, and calculate the latter sampling data all at once, thereby significantly reducing data processing time. This makes it possible to sufficiently perform the above-mentioned processing even with a general-purpose arithmetic element. Furthermore, it also has the effects described below.

(1) Even when the input waveform fluctuates greatly, it is possible to perform highly accurate measurement faithful to the input waveform with respect to the measurement cycle. Therefore, even a distorted waveform can be accurately measured.

(2) The simultaneous sampling method of instantaneous values of multiple inputs enables calculation output between multiple inputs.

Therefore, as will be explained in the embodiment, the active power value can be determined only by calculation without requiring a measuring circuit.

(3) Since an arithmetic processing unit is used for measurement, even when display and recording functions are provided, the same arithmetic processing unit and memory section can be shared, and the entire device can be configured simply.

(4) It provides a method that can be made smaller and lighter with a simple circuit configuration and has excellent economical effects.

[Brief explanation of drawings]

Figure 1 is a block diagram of the equipment used in the conventional measurement method.
Fig. 2 is a block diagram of an embodiment of the device used in the measurement method of the present invention, and Figs. 3, 4, and 6 are signal waveform diagrams of each part. 0 11... Current signal input Terminal, 12...
Voltage signal input terminal, 13...output terminal, 14.1
5...Sample hold circuit, 16...
・Multiplexer, 17...A/D converter, 1
8... Arithmetic processing unit, 19... Memory section. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 5

Claims (1)

[Claims] It has a sample and hold circuit, an A/D converter, a multiplexer/memory section, an arithmetic processing unit, and an output section, and time-divides the arbitrary period of the AC voltage and current signal input waveform into multiple sampling periods with the same time period. Each time-division sampling data is read sequentially, and the read result is stored in the appropriate memory section.Then, the voltage and current are input as individual inputs for each time-division sampling data, and the active power and apparent power are input as voltages. , a multi-element calculation measurement method for AC signals, characterized in that time-division same time period sampling data of current are calculated respectively, the calculation results are then aggregated, and the results are output as calculation measurement data.