JPS6068734A - Voltage current transmission system by optical fiber - Google Patents

Abstract

PURPOSE:To allow a large input voltage to be received and also to improve the accuracy at phase difference detection by changing the level of a frequency pulse after V-F conversion so as to represent a zero point and a positive/negative level of an original waveform. CONSTITUTION:An AC input 2 fetched from a current transformer 1 is subject to full-wave rectification by a rectifier 3, and the rectified waveform is converted into a frequency pulse proportional to a voltage by a V-F converter 4. On the other hand, the polarity of the fetched AC input 2 is detected by a discriminator 5 so as to output a positive/negative signal. The level of the frequency pulse converted by the V-F converter 4 according to the output is changed by a pulse voltage switching device 6. Then the zero point of the fetched AC input 2 is detected by a detector 9 and an output pulse 11 is outputted by applying its output to a pulse voltage generator 10. Thus, a waveform being the synthesis of outputs of the generator 10 and the switching device 6 is converted into a light by an optical converter 12 and the light is transmitted by an optical fiber 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a system for transmitting electrical quantities by means of optical fibers.

Recently, optical fibers have come to be used as a means of transmitting electrical signals.

In a system that transmits 1fi of electricity extracted from the power system, the amount of electricity generated by humans is generally biased so that the maximum amount of electricity for fish is 4G, and then converted to V- and -F before being transmitted. In this method, applying a bias increases the maximum voltage and -1: the dynamic range of the converter becomes smaller.Also, when the original electricity m is reproduced from the transmitted signal, the conversion delay time increases. , it is difficult to accurately detect the zero point of the original electrical quantity due to conversion errors.

The present invention is designed to represent the zero point J3 and positive and negative values of the original waveform by changing the magnitude of the frequency pulse after VF conversion.Examples will be described below with reference to the drawings.

In FIG. 1(a), AC power 2 taken in from a current transformer 1 is full-wave rectified by a rectifier 3. This AC input waveform is shown in FIG. 2(a).

This rectified waveform is converted by a V-F converter 4 into a pulse having a frequency proportional to the voltage.

On the other hand, a positive/negative determiner 5 detects the positive/negative of the input AC human power 2 and outputs a positive/negative signal. According to this output, the V-
The magnitude of the pulse of the frequency converted by the F converter 4 is changed by the pulse voltage switch 6.

In other words, when a positive signal is detected by the positive/negative determiner 5, the output of the pulse voltage switch 6 becomes the magnitude of the output pulse 7 as shown in FIG. When it is detected 1c, it has the magnitude of the output horn pulse 8 shown in FIG. 2(b).

Next, the zero point of the input AC human power 2 is detected by a zero point detector, and the output is applied to the pulse voltage generator 1o, thereby producing an output pulse 11 shown in FIG. 2(b).

The output waveform shown in FIG. 2(b), which is a combination of the output of the pulse voltage generator 10 corresponding to the zero point of the AC input power 2 and the output of the pulse voltage switch 6 corresponding to the positive/negative of the AC input horn 2, is transferred to the optical converter. 12 converts it into light and transmits it through an optical fiber 13.
-ru.

On the receiver side shown in FIG. 1(b), the optical signal sent through the optical fiber 13 is received, the optical-to-electrical converter 14 converts it into a frequency pulse, and the central processing unit 15 converts the waveform into a frequency pulse.
Effective value measurement, phase difference measurement, harmonic measurement, etc. can be performed.

Moreover, by arranging a plurality of optical-electrical converters 14-... and optical fibers 13-..., a plurality of electricity M can be handled.

According to the present invention, compared to a method in which the bias is converted to V-F, the positive and negative values are expressed by the magnitude of the pulse, so that a large voltage can be input. Furthermore, since the zero point can be determined accurately, there is an advantage that the accuracy in detecting the phase difference is improved.

Furthermore, since transmission is performed using optical fiber, there are advantages such as a longer transmission distance and significantly improved signal reliability against noise.

[Brief explanation of the drawing]

Figure 1 <a> is a block diagram showing the transmitter side of the present invention, Figure 1 (b) is a block diagram similarly showing the receiver side, Figure 2 (a) is an AC input waveform of the transmitter, tl) respectively accept the output waveforms. In the figure, 1 is a current transformer 2 is an AC input 3 is a rectifier 4 is a V-F converter 5 is a positive/negative judge 6 is a pulse voltage switcher 9 [and a zero point detector 10] The pulse voltage generator 12 and the optical converter 13 are optical fiber 1711 optical-to-electrical converters.Patent applicant: Takagaku Seisakusho Co., Ltd.Procedure Correction Harm (voluntary) Kai Patent dated July 7, 1982 Director-General of the Agency, 6゜1, Indication of the case l111 Japanese Patent Application No. B743 (-1,0 No. 2, Title of the invention: Optical fiber voltage and current transmission system 3, Right case to be amended) Applicant's postal code: 100 Address: 2-2-1 Hitote-cho, Chiyo 11-ku, Higashisune Subject of amendment Contents of the amendment in the scope of claims and detailed description of the invention in Mei 111 (1) Mei 11 I 1-2, patent Amend the full text of the claims as shown in the attached sheet. 9(2) Page 3 of the specification, line 11, ``...The output is'' and ``Figure 2.
Added "for example" between "・". (3) Delete lines 12-13 of the same page [also using the sign/negative determiner 5]. (4) Same page 13-1 '4 bl The size of the output horn pulse 8 shown in FIG. 2(b) is obtained. '', an output pulse 8 having a different magnitude from the output pulse 7 is output. (5) On the same page, line 18, after "...is output.", "These output pulses 7, 8, and 11
are set to different sizes. ” has been added. (6) Page 4, line 13 of the specification: ``...Put the positive and negative J and 1 into the pulse...''
・Added "r J5 and zero point" between ". 2. Claims: A rectifier that performs full-wave rectification of AC input taken in from a current transformer;
V converts the rectified waveform into a pulse with a frequency proportional to the voltage
- an F converter, a positive/negative determiner that detects the positive/negative of the AC input and outputs a positive/negative signal; and a pulse loop size of the frequency converted by the V-F converter according to the output of the positive/negative determiner; a pulse voltage switcher for changing the AC input horn; a zero point detector for detecting the zero point of the AC input horn and outputting a zero point signal;
Is the output of the zero point detector the pulse? a pulse voltage generator that converts the output of the HJi-switcher into a pulse having a different magnitude, and an optical conversion that converts a signal obtained by combining the output waveform of the pulse voltage generator and the output waveform of the pulse voltage switch into light. At the same time, the output side of the optical converter and the receiver side are connected with an optical fiber, and in order to suppress reception, an optical-electrical converter is provided that converts the light received from the transmitter side into frequency pulses. A voltage and current transmission system using optical fiber, characterized by being equipped with a converter.

Claims (1)

[Claims] A rectifier that performs full-wave rectification of the AC input taken in from the variable WL 'PI, a V-F converter that converts the rectified waveform into a /< pulse with a frequency proportional to the voltage, and a V-F converter that detects the positive and negative of the AC input and converts it to positive and negative. a pulse voltage switch that changes the magnitude of the pulse of the frequency converted by the V-F converter according to the output of the positive/negative determiner, and a pulse voltage switch that detects the zero point of the AC input. a zero point detector that outputs a signal of zero + ia; a pulse voltage generator that converts the output of the zero point detector into pulses; and the output waveform of the pulse voltage generator and the pulse voltage switcher. The transmitter side is equipped with an optical converter that converts the signal obtained by combining the output waveforms of the
The output side of the optical converter and the receiver side are coupled by an optical fiber, and the receiver side is equipped with an optical-to-electrical converter that converts the light received from the transmitter side hx into frequency pulses. A voltage and current transmission system using optical fiber, which is characterized by: