JPH0356034A - Digital type voltage regulating relay - Google Patents

Abstract

PURPOSE:To decrease the number of parts by arithmetically operating sampling frequency from a digital obtained by A/D conversion, acquiring a correction factor, signal obtaining the execution value of the digital signal on the basis of the correction factor and making the digital signal unrelated to the frequency. CONSTITUTION:An analog signal is input from an input terminal 1, sample-held through an analog filter 2 and input to a multiplexer 5. An output from the multiplexer 5 is A/D converted 6, and input to a CPU 7. An output from the CPU 7a is input to a frequency computing element 9 through a digital filter 8, and a sampling period is arithmetically operated. A correction factor is arithmetically operated 10 from the sampling period, and the effective value of a digital signal is arithmetically operated 11 on the basis of the correction factor, and input to a voltage judging apparatus 12. Accordingly, the voltage juding apparatus 12 judges the value of voltage regardless of frequency and outputs it, thus decreasing the number of hardware and reducing cost, the inhibiting the effect of the harmonics.

Description

[Detailed Description of the Invention] A. INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to a digital voltage regulating lightning device.

B. Summary of the Invention The present invention provides a highly reliable digital voltage regulating relay by sampling a normal AC waveform as a human input signal and performing frequency calculation, correction coefficient calculation, and effective value calculation based on this data. Obtain type voltage regulating relay.

C. Conventional technology Figure 4 shows conventional digital voltage regulation @! This shows the schematic configuration of the electric appliance, where l is a voltage transformer that detects analog voltage from power lines, etc., 2 is an analog filter, and 3 is an effective value conversion circuit (RMS converter) that converts the AC voltage signal of analog filter 2 into an effective value. , 4 is a sample hold circuit, 5
is a multiplexer, 6 is an analog/digital (A/D') conversion circuit that converts the analog voltage signal of the multiplexer 5 into a digital voltage signal, and 7 is an arithmetic processing unit that performs arithmetic processing based on the digital signal of the A/D conversion circuit 6. (C
PU).

In the digital voltage regulating relay shown in FIG. 4, the voltage transformer l. Analog filter 2. RMS converter 3, sample hold circuit 4. Multiplexer 5 and A/D
Transducer 6 forms the input.

In this input section, the effective value conversion circuit 3 converts the input voltage into a DC voltage proportional to the effective value, and then the sample and hold circuit 4 samples the input voltage at predetermined time intervals. In the calculation process $7, the deviation between the sampled input data and the reference voltage setting value, which is the center value of the control target for the system voltage, is constantly calculated.

D. Problems to be solved by the invention A voltage regulating relay must have an error performance of about ±1% due to its characteristics, but it is also necessary to guarantee performance with a similar error even when the frequency changes. .

Generally, an effective value conversion circuit is used, but although this effective value conversion circuit is expensive, its performance is affected by harmonics.

The present invention has been made in view of the above-mentioned problems, and its purpose is to perform frequency calculation in an arithmetic processing section. By performing correction coefficient calculation and effective value calculation, a high performance and highly reliable digital voltage adjustment joint 7M. It is to provide a vessel.

E. Means and Effects for Solving the Problems In order to achieve the above-mentioned objects, the present invention provides an input section that samples an analog input voltage signal and converts it into a digital voltage signal, and an input section that performs arithmetic processing based on the digital voltage signal. In a voltage regulating relay comprising a calculation processing unit that adjusts the voltage, the calculation processing unit is combined with frequency calculation means that calculates a frequency of sampling data based on the digital voltage signal, and a frequency calculation unit that calculates the frequency of sampling data based on the digital voltage signal. correction coefficient calculation means for calculating a correction coefficient based on frequency; effective value calculation means for calculating an effective value of the digital voltage signal based on the correction coefficient calculated by the correction coefficient calculation means; and correction coefficient calculation means. A digital voltage regulating relay is constituted by a voltage value determining means that obtains a frequency-independent effective value from the calculation result of the calculation result and the calculation result of the effective value calculation means.

This reduces the number of hardware parts, making the device inexpensive and highly reliable, while suppressing the effects of harmonics and improving functionality.

F. EXAMPLES Examples of the present invention will be explained below with reference to FIGS. 1 to 3, starting from red.

FIG. 2 shows a schematic configuration of a digital voltage regulating relay according to an embodiment of the present invention, which essentially consists of a voltage transformer 1. Analog filter 2. Sample hold circuit 4. Multiplexer 5 is composed of an A/D converter 6 and an arithmetic processing section 7a.

As shown in FIG. 1, the calculation processing section 7a includes a frequency calculation section 9 that calculates a frequency based on the digital signal of the digital filter 8, and a correction coefficient based on the frequency calculated by the frequency calculation section 9. A correction coefficient calculation unit 10 and an effective value calculation unit 11 that calculates an effective value based on the correction coefficient.
and a voltage value calculation unit l2 that calculates a frequency-independent effective value voltage value from the calculation results of the correction coefficient calculation unit 10 and the effective value calculation unit 11.

In the digital voltage regulating relay configured as described above, the input is a normal AC waveform sampled, and the frequency is determined from this data as in step Sl in FIG. For example, the current sampling data is expressed as τ at an + i air angle.
゜If the previously sampled value is an-In and the previous one is an-to... then α”a'n-l
anXan-2 = 2A"sin"(ωt-r)-2A"sin (c
)j sin(ωt-2r)=2A” { (sin
ωt + cos r − cos ωt sin r)”
−sin ωt (sin ωt cos 2r: −
cosrsin 2r) )=2A” cos(ω
t-ωv) sin'r=2A"sin"r...
−(1) is obtained. Here, a n=4 2A Sin
(t) t, 'ah-+ 1J 2A sin
((L) t r), gn-t::7 2A sin (ωt2τ).

Similarly, β=an"-* an@aan-*=2A"S1n"
(2r)・・・・・・・・・(2) β／α−4 cos'τ ・・・・・・
...(3) The electrical angle in a certain period of time is calculated using 4 cos'' τ, and in other words, the frequency can be found.

Next, the effective value is α = 2A'sin' r, which has been found using equation (1). Find sin' τ from the previous 4 cos' τ, and calculate the correction coefficient by multiplying this K by the previous α. ,X
=cr ・K=2A'sin"r・(1/sin"
v)2A' - (4) Since the effective value can be found regardless of the frequency, the effective value calculation is executed as shown in step S2. As a result, error correction based on the frequency is performed as shown in step S3, and then relay calculation is performed in the voltage value determination section 12 as shown in step S4.

G. Effects of the Invention The present invention is as described above, and according to the digital voltage regulating appliance of the present invention, effective value conversion is performed by software of the arithmetic processing section without using an effective value conversion circuit. Therefore, the cost of hardware is reduced by 1, and since the number of hardware items is reduced, reliability is improved. Furthermore, since a dinotal filter can be applied, it is less affected by high rise waves, the analog filter at the input section is not expensive enough to eliminate aliasing errors, and it is resistant to secular changes in offset.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of a digital voltage regulating relay according to an embodiment of the present invention, FIG. 2 is a block diagram showing a schematic configuration of a digital voltage regulating relay according to an embodiment of the invention, and FIG. FIG. 2 is an operation flowchart of the voltage regulating U electric appliance, and FIG. 4 is a block diagram showing a schematic configuration of a conventional digital voltage regulating relay. 1... Voltage transformer, 2... Analog filter, 4...
...sample hold circuit, 5...multiplexer,
6... Analog/digital converter, 7a... Arithmetic processing section, 8... Digital filter, 9... Frequency computing section, 10... Correction coefficient computing section, l1... Effective value computing section , 12... Voltage value determination unit. 2 people outside Figure 1

Claims (1)

[Claims] (1) In a voltage adjustment relay that includes an input section that samples an analog input voltage signal and converts it into a digital voltage signal, and an arithmetic processing section that performs arithmetic processing based on the digital voltage by the input section and adjusts the voltage, The processing section includes a frequency calculation means for calculating the frequency of the sampling data based on the digital voltage signal, a correction coefficient calculation means for calculating a correction coefficient based on the frequency calculated by the frequency calculation means, and a correction coefficient calculation means for calculating the correction coefficient based on the frequency calculated by the frequency calculation means. effective value calculation means for calculating the effective value of the digital voltage signal based on the correction coefficient calculated by the means; and an effective value independent of frequency from the calculation result of the correction coefficient calculation means and the calculation result of the effective value calculation means. What is claimed is: 1. A digital voltage regulating relay characterized in that it is constructed by means for determining a voltage value.