JPS5950369A - Electric quantity measuring device - Google Patents

Abstract

PURPOSE:To eliminate an error of an output signal, by executing a compensation so as to eliminate an error generated in an optical transfer path of an optical beam after being divided into two by an analyser, in an electric quantity measuring device for measuring an electric quantity by utilizing the polarization of light. CONSTITUTION:A light source 70 consists of light emitting diodes 71, 72 for irradiating the light of wavelength lambda1, lambda2. A polarizer 21 is a wavelength selecting type polarizer, and polarizes light of wavelength lambda2 irradiated from a coupler 80, but does not polarize light of wavelength lambda1. Two lights of wavelength lambda2 passing through an analyzer 30 contain a signal component of an opposite phase to each other, and light of wavelength lambda1 does not contain a signal component in light intensity. In an operating means 110, the first gain adjusting device 111 and the second gain adjusting device 114 adjust the gain of an output signal of the first photoelectric converter 90 and the second photoelectric converter 100, and compensated so as to eliminate an error due to a loss variation generated in an optical transfer path of an optical beam, and an error generated in an output signal Vout can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical quantity measuring device that measures current, voltage, power, magnetic field, etc. (hereinafter referred to as electrical quantity) using polarized light.

FIG. 1 is a block diagram of a conventional example of this type of electrical quantity measuring device.

In FIG. 1, 10 is a light source such as a light emitting diode;
0 is a light application sensor, 30 is an analyzer, 40 is a first photoelectric converter 50 is a 20th photoelectric converter, and 60 is a calculation means.

In the optical sensor 20, 21 is a polarizer, 22 is a λ/
4 plates, 23 is an electro-optic effect element, and 24 is a magneto-optic effect element. A voltage m is applied to the electro-optic effect element 23, and a current i is supplied to the magneto-optic effect element 24, whereby the electro-optic effect element 23 and the magneto-optic effect element 24 change the polarization state of the light passing therethrough.

The light beam, which has become circularly polarized by being irradiated from the light source 10 onto the polarizer 21 and the λ/4 plate 22, undergoes a phase change proportional to the applied voltage V by the electro-optic effect element 23, and becomes elliptically polarized. . This southerly polarized light beam undergoes rotation of the plane of polarization in proportion to the amount of supplied current, and the principal axis of the circularly polarized light is rotated.

Furthermore, this light beam is separated into polarization components in two specific orthogonal directions by the analyzer 30, and the polarization components of the light intensity signal are provided to the first photoelectric converter 40 and the second photoelectric converter 5014. In the first photoelectric converter 40, 41 is a photodiode, which converts one optical intensity signal Io(1+3) decomposed into polarization components in two specific orthogonal directions by the analyzer 30 into a photocurrent corresponding to the optical intensity. Convert to signal. Here, IO is a signal component generated by the Sld sensor, and IO is a light intensity signal when the signal component of SE/SKAMO is zero.

A current/voltage converter 42 converts the photocurrent signal from the photodiode 41 into a voltage signal and outputs the voltage signal.

- converts the other optical intensity signal Io(1-3) polarized by the analyzer 30 into a photocurrent signal corresponding to the optical intensity. 52 is a current-voltage converter, which converts the photocurrent signal from the photodiode 51 into a voltage signal and outputs the voltage signal. In the calculation means 60, 61 is an adder, which adds the output signal of the first photoelectric converter 40 and the output signal of the second photoelectric converter 50. A subtracter 62 subtracts the output signal of the second photoelectric converter 50 from the output signal of the first photoelectric converter 40. 63 is an operational amplifier to which the output of the adder 61 and the output of the reference voltage source 64 are applied. and,
The output of the operational amplifier 63 is given to the light emitting diode 10, and a feedback signal is given to the light emitting diode 10 so that the output voltage of the adder 61 becomes a constant value Vr.

In the forward air volume measuring device having such a configuration, the subtractor 62
The signal generated is extracted as an output signal, and this output signal becomes a power signal corresponding to the product of the voltage V applied to the electro-optic effect element 23 and the current l supplied to the magneto-optic effect element 24. The power is measured by When V=constant (-1j=o) and 1==0, the output signal corresponds to the value of the applied voltage V, and the voltage is thereby measured. v=0. When i = constant (key 0), the output signal is current 1
The current is measured directly against the ICL.

However, in such electrical quantity measuring devices, the light transmission path is often long in photoanalysis), and the fluctuations due to light loss etc. in the light I-R path are different between the two paths, so the device There was a point where an error occurred in the output signal.

The present invention was developed in order to eliminate the above-mentioned problems, and corrects the light beam after it is divided into two by an analyzer to remove the error that occurs in each light propagation path a. However, it is an object of the present invention to provide an electrical quantity measuring device that eliminates errors in output signals.

FIG. 2 is a schematic diagram of an embodiment of the electrical quantity measuring device according to the present invention. In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals.

In FIG. 2, 70 is a light source, 80 is a coupler, 90 is a first photoelectric converter, 100 is a second photoelectric converter, and 110 is a calculation means.

The light source 70 includes a light emitting diode 71 that emits light with a wavelength of λ2 and a light emitting diode 72 that emits light with a wavelength of λ2. The coupler 80 combines the light emitted by the light emitting diodes 71 and 72. The polarizer 21 is a wavelength-selective polarizer, and polarizes the light of the wavelength λ2 of the light emitted from the coupler 80, but does not polarize the light of wavelength λ2. Therefore, among the light that passes through the polarizer 21, the light with wavelength λ2 has a signal component in the light intensity, but the light with wavelength λ
The light □ does not have a signal component in its light intensity. In the first photoelectric converter 90, 91 is a demultiplexer, and the analyzer 30
One of the light beams separated by the wavelength □(
is separated into light of wavelength λ2 and light of wavelength λ2. 92. '93 is a photodiode, which has a wavelength λ separated by a demultiplexer 91.
The light of □ and the light of wavelength λ2 are converted into photocurrent signals according to the respective light intensities.

Reference numerals 94 and 95 indicate current-voltage converters υ, which convert the photocurrent signals from the photodiodes 92 and 93 into electrical signals and output the electrical signals. In the second photoelectric conversion means 100, 101 is a demultiplexer, which separates the other light beam separated by the analyzer 30 into the aforementioned light of wavelength ^ and light of wavelength λ2.

102 and 103 are replaced by photodiodes. 1.04
．． 195 is a current-voltage converter, and photodiode 1
Converts the photocurrent signal from 02.103 into a voltage signal and outputs it. In the calculation means 110, 1111d is a first gain adjuster and is supplied with the output signal of the current-voltage converter 94. 112 is a subtracter, and the first gain adjuster 11
The output signal of the current-voltage converter 104 is subtracted from the output signal of the current-voltage converter 104. The output of the subtracter 112 is fed back to the first gain adjuster 111 as a feedback signal by the feedback circuit 113, so that the output signal of the first gain adjuster 111 becomes equal to the output signal of the current-voltage converter 104. The gain is adjusted as follows. 114 is a second gain adjuster to which the output of the current-voltage converter 95 and the feedback signal of the feedback circuit 113 are applied. The second gain adjuster 114 is the first gain adjuster 1
11, and by receiving the feedback signal from the feedback circuit 113, it performs gain adjustment in the same manner as the first gain adjuster 111. 115 is an adder that adds the output of the second gain adjuster 114 and the output of the current-voltage converter 105. 116 is an operational amplifier to which the output of the adder 115 and the output of the reference voltage source 117 are applied. The output of the operational amplifier 116 is given to the photodiode 72, and a feedback signal is given to the light emitting diode 72 so that the output voltage of the adder 115 becomes a constant value Vr.

A subtracter 118 subtracts the output of the current-voltage converter 105 from the output of the second gain adjuster 114. The output signal of this subtracter 118 becomes the output signal of the device.

In the electrical quantity measuring apparatus having such a configuration, one stroke force, voltage, electric power, etc. are measured in the same manner as the electrical quantity measuring apparatus shown in FIG.

Furthermore, for the light beam after it has been divided into two by the analyzer 30, errors in the output signal of the apparatus due to fluctuations in optical loss occurring in the respective optical transmission paths are removed in the following manner.

Regarding the light beam immediately after being divided into two by the analyzer 30, the first light? (l The light intensity signal of the light beam sent to the converter 90 is □10.7. The light intensity signal of the light beam sent to the second photoelectric converter 100 is □2+I22.

Here, □□: An optical intensity signal of wavelength λ□ among the optical signals sent to the first photoelectric converter 90.

■. □: Optical 1 intensity signal of wavelength λ2 among the optical beams sent to the first photo-□-electrical converter 90.

Step □2: Send to second photoelectric converter 100 With the hammer of the light beam, Light intensity signal of wavelength.

Engineering. □-42 photoelectric converter 100 Of the light beams that are Optical intensity signal of wavelength λ2.

Since the lights of two wavelengths λ that have passed through the analyzer 30 contain signal components S having opposite phases to each other, the light intensity signals 112 and 12
2 is ■, □=122(1+5)(1) ■. 2”f22 (1'S)
(2) becomes. On the other hand, since the light with the wavelength λ□ does not include the signal component S in its light intensity, the light intensity signal processing □1. Engineering □2 is
"11"fll"Eng.12(3).The first photoelectric converter 9o and the second photoelectric converter 10
The optical intensity signal that has changed due to optical loss in the optical transmission path before being sent to 0 is processed. ; and work □2 + I22 ■: L1 + "21" α (work 11 + work 2 □) (4) 1
12 ” ” 22 ” β (Eng. 12 ” ” 22 ) (5
). Here, α and β are coefficients caused by optical loss. Errors in the optical intensity signals that occur in the optical transmission path from the analyzer 30 to the first photoelectric converter 9o and from the analyzer 3o to the second photoelectric converter 100 are determined by the following: The coefficients α and β are different because of differences in optical loss, etc.

The wavelengths λ and λ light separated by the demultiplexer 91 are 2 photodiodes 92.93 and current-voltage converters 94.9.
Let the electrical signals converted by 5 be V and V, and 11
-21 The light of wavelength λ□ and A2 separated by the demultiplexer 101 is sent to the photodiode 102, 103 and the current-voltage converter 10.
The electrical signal converted by 4゜105 is V□2 and v2
2, V□1=咀=α工□□ (6)■21
” Engineering 21 = α Engineering. □ (7) v12
“112”β112(8) v22° 工22=β”22.
(9) If the output signal of the first gain adjuster 111 is vll, then vll = AGC"11
(11) 800 'first gain adjuster 11
Control gain of 1.

becomes. Substituting equation (6) into equation (l(), vllo
The first gain adjuster 111 receives the signal from the feedback circuit 113.
The gain is adjusted so that v'-v=o by the feedback signal. By substituting v'=, v and equation (8) into α◇formula 1 12, we get AGC'''111''ββ12 Here, from equation (3), we get □□bow. Since A
GCα“β (b).

If the output signal of the second gain adjuster 114 is v21,
Since the second gain adjuster 114 is the same as the first gain adjuster 111 and performs gain adjustment in the same way as the first gain adjuster 111, the control gain is also the same as that of the first gain adjuster 111.
11, '21 '800, '21', and from equation (9) v21°AGC '21 '
It becomes 61. Substituting the θne formula into the α1 formula, v2 = β. □ α→. The output signal v2'1. of the adder 115 is sent to the operational amplifier 116. +v22 is obtained from equation 64 and equation (9) as ■2'
1. +V22=β(121" 22). Substituting equations (1) and (2) into this, we get ■21 +v22 ”
β1r22(z +s) +T22(z −s)'?
.

°2β! 2□ This signal v + v22 is the neutral voltage V of the reference voltage source 117
Since it is controlled to be equal to r, Vr=
2β engineering becomes 220 ri. The output signal of the device is the output signal v2 of the subtracter 118
N-■22, Natteite, 04 type and (9) type Kara, ■2
1-v22°"2:L-"22)=β1f22(1
+5)-β22(1-8)j=2β2゜S, and from the CI equation, v21-v22°Vr-8'
H, the coefficients α and β related to the error of the optical intensity signal
is canceled, and the output signal v217v2° of the device depends only on the constant voltage value Vr and the signal component S. As a result, the light beam after being divided into two by the analyzer 30 is corrected to remove errors due to optical loss occurring in each optical transmission path, and errors in the output signal of the device are removed. Ru.

According to the electrical quantity measuring device having such a configuration, the first gain adjuster 111 and the second gain adjuster 114 adjust the gains of the output signals of the first photoelectric converter 90 and the second photoelectric converter 100. The optical beam after being divided into two by the analyzer 30 is corrected to remove errors due to loss fluctuations occurring in each optical transmission path. Therefore, errors occurring in the output signal of the device can be Can be removed.

FIG. 3 is a block diagram of main parts of another embodiment of the electrical quantity measuring device according to the present invention.

In FIG. 3, 119 is a divider, which divides the output signal V□1 of the first photoelectric converter 90 and the photoelectric converter 1 of
00 is divided by the output signal v12 to obtain the electric signal v1.
Output □/vi2. 120 is a gain adjuster, and the electric signal v21 output by the second photoelectric converter 100 is determined by the electric signal v1□/v12 sent from the divider 119.
The gain is adjusted and an electrical signal V' is output. The adder 115 adds the output signal V° of the gain adjuster 120 and the output signal V 2 of the first photoelectric converter 90 . Then, the output signal V21 + V2° of the adder 115 is sent to the operational amplifier 116. The subtracter 118 subtracts the output signal V 2 of the first photoelectric converter 90 from the output signal v2□ of the gain adjuster 120. Then, the output signal 2v21-22 of the subtracter 118 is outputted as the output signal of the device.

In the electrical quantity measuring device having such a configuration, the divider 11
Electrical signal ■1 given to gain adjuster 120 by 9
□/V1□ consists of equations (6) and (8), and (3)
From the formula, since □1=11°, it becomes. As shown in the equation θη, the output signal of the divider 119 V□□/v
12 is an error due to a loss of the light intensity signal that occurs in the light transmission path from the analyzer 30 to the photoelectric converter 90 of the broom 1;
This is related to an error in the light intensity signal that occurs in the light transmission path from the analyzer 30 to the second photoelectric converter 100. The gain adjuster 12 is controlled by such electric signals v1□/V□2.
0 adjusts the gain of the output signal v2□ of the first photoelectric converter 9o, and removes errors caused by optical loss occurring in each optical transmission path for the light beam after it is divided into two by the analyzer 30. Make corrections as follows. This then eliminates errors in the output signal of the device.

According to the electrical quantity measuring device having such a configuration, in addition to the effects obtained by the electrical power measuring device shown in FIG. can do.

In addition, although the case where the light source 7o was a light emitting diode was demonstrated in the Example, the light source 7o may be other than this.

Further, in the embodiment, a case has been described in which the light source 70 is composed of a light source that emits light with a wavelength λ□ and a light source that emits light with a wavelength λ2, but the light source 70 is not limited to this.
It may be one light source that irradiates one light and one wavelength of light. This allows the configuration of the device to be simplified.

Further, in the embodiment, a case has been described in which the optical sensor 20 has an electro-optic effect element 23, a magneto-optic effect element 24, etc., and is capable of detecting electric power, voltage, and current. The optical application sensor 20 is not limited to one that can detect only voltage without the magneto-optical element 24, and one that can detect only the current without the electro-optical element 23 and the λ/4 plate 2 sheet metal 2. According to the invention, the light beam after being seen into two parts by the analyzer is corrected to remove errors due to optical loss occurring in each optical transmission path, and errors in the output signal are removed. It is possible to provide an electrical quantity measuring device.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional example of an electrical quantity measuring device.
FIG. 2 is a block diagram of one embodiment of the electrical quantity measuring device according to the present invention, and FIG. 3 is a block diagram of another embodiment of the electrical quantity measuring device according to the present invention. 20... Optical application sensor, 30... Analyzer, 80...
・Coupler, 9o...first photoelectric converter, 100...
Second photoelectric converter, 110... calculation means. 1st [2]

Claims (1)

[Claims] A coupler that combines two lights of different wavelengths, an optical sensor that receives a light beam from the coupler and changes the polarization state of the light beam in accordance with the amount of electricity to be measured, and a light beam that is emitted from the optical sensor. an analyzer that divides a light beam into two orthogonal light beams, and a light intensity signal of one of the light beams emitted from the analyzer that divides the light intensity signal of one of the light beams emitted from the analyzer into light intensity signals of the two lights having different wavelengths. a first photoelectric conversion means for converting a light intensity signal into an electrical signal; and a light intensity signal of the other light beam emitted from the analyzer, which is divided into light intensity signals of two lights having different wavelengths. a second photoelectric conversion means for converting the light intensity signal into an electric signal; and a second photoelectric conversion means for converting the light intensity signal into an electric signal;
The gain of the electrical signals output by the photoelectric conversion means and the second photoelectric conversion means is adjusted, and the electric signals corresponding to the optical intensity signals of the same wavelength output from the first photoelectric conversion means and the second photoelectric conversion means are generated. 1. An electrical quantity measuring device characterized by comprising: calculating means for determining a sum signal and a difference signal of these signals and generating a signal related to the difference signal/sum signal as an output signal.