JP3287799B2 - Distribution line monitoring and control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distribution line monitoring and control system for remotely controlling line equipment between a master station and a slave station.

[0002]

2. Description of the Related Art Conventionally, in this type of distribution line monitoring and control system, information (electric signals) of line devices for setting distribution line lines is frequency-modulated or phase-modulated by a modulation method such as FSK, FM, or PSK. Although data transmission has been performed using a metal cable, recently, an optical transmission method capable of higher-speed data transmission has been used. Further, when trying to multiplex other signals by an optical transmission method, generally, an FDM (frequency division multiplexing) method in which information to be multiplexed is transmitted on another carrier (single sine wave) or a multiplexing method is used. There is a TDM (Time Division Multiplexing) system for transmitting multiplexed information on a time axis and transmitting the multiplexed information.

[0003]

However, the above-mentioned FDM
In the system, when a mixer / distributor for an analog signal and another signal to be multiplexed are digital signals, a digital modulator / demodulator for a multiplexed signal is required, which complicates the system configuration and increases the manufacturing cost of the system. There was a problem that the cost was high. Further, in the TDM system, since it is necessary to synchronize signals with each other, a synchronization device is required. In this case, too, there is a problem that a system configuration is complicated and a system manufacturing cost is increased. .

The present invention has been made in view of the above problems, and has as its object to provide a distribution line monitoring and control system capable of performing optical transmission with a simple and inexpensive configuration.

[0005]

To achieve the above object, a distribution line monitoring and control system according to claim 1 of the present invention.
Both, the line device of the switch for setting the line of bridges to power distribution lines to the column, is connected to該線path equipment, the on-off control of the switches based on a control signal from the master station, switch in the power line monitoring and control system with an analog signal indicating the state and the slave station for transmitting to said master station, the slave station side, a clip circuit for generating a first digital signal by clipping the analog signal , The first day
Digital signal differs greatly in its fundamental frequency from
A second digital signal indicating the form of power supply to the road device
A signal generator for generating the first digital signal ;
A mixed-means you mixed serial second digital signal, be transmitted based on the mixed engaged signal by emitting an optical signal to the master station
An optical signal emitting means is provided that, on the other hand, the parent station side, a receiving means comprising a light receiver for receiving the optical signal, and said analog signal and a second digital signal from the optical signal receiving light respectively Moketako and a band-pass filter or a signal extraction means consisting of a low-pass filter separates and extracts
It is characterized by.

That is, an analog signal indicating the state of a switch from a slave station is clipped, a pseudo digital signal is generated, and a second digital signal is added to or multiplied by the digital signal and mixed therewith. Emits an optical signal based on the mixed signal. The signal received by the light receiver is reproduced into the original analog signal and digital signal by a filter or the like, and output to the master station.

Preferably, as set forth in claim 2,
The signal generator indicates a power supply mode to the line device.
As a second digital signal, the fundamental frequencies
The two different digital signals f1 and f2 are supplied to the power supply
It shall be generated complementarily according to the supply form,
In the means, power is generated complementarily according to the power supply mode.
One of the digital signals f1 and f2 generated is
To be always mixed with one digital signal
Is desirable.

In the master station, the received optical signal is
The first digital signal and the digital signal f
Each of the second digital signals consisting of one of f1, f2
It is desirable to be configured to separate and extract.

At this time, in the master station, the digital
Only one of the signals f1 and f2 is detected and transmitted to the line equipment.
It goes without saying that the power supply mode may be determined.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A distribution line monitoring and control system according to the present invention will be described with reference to FIGS. FIG.
1 is a configuration diagram illustrating a schematic configuration of a distribution line monitoring and control system according to the present invention. In the figure, a switch 12 for setting a line of a distribution line 11 bridged by the support 10 is installed on a support 10, and the switch 12 is connected to a slave station 13.

The slave station 13 includes two sets of light emitting devices 14 and 17 for up and down, optical fibers 15 and 18 and the light receiving device 1.
6 and 19 are connected to the master station 20 respectively.
The slave station 13 is connected to the light emitting device 14 and the light receiving device 19 via metal cables 21 and 22, respectively. The master station 20 is connected to the light receiving device 16 and the light emitting device 17 via metal cables 25 and 26. Each is connected.

Thus, between the slave station 13 and the master station 20,
Distribution line monitoring and control by transmitting and receiving the state signal and control signal of the switch 12 becomes possible. That is, the slave station 13 detects the ON / OFF state of the switch 12, sends a state signal indicating the state from the light emitting device 14 to the master station 20,
A control signal for performing on / off control of the switch 12 transmitted from the master station 20 is captured by the light receiving device 19, and on / off control of the switch 12 is performed based on the control signal.
For example, when a ground fault or the like occurs, the switch 12 is remotely controlled to switch the transmission line.

A power supply 23 is connected to the light emitting device 14. The power supply 23 has a battery 24 inside,
Switching the distribution line 11 or the battery depending on the situation, the power supply for the respective devices of the light emitting device 14 and light receiving device 19
I do. That is, the power supply 23 normally supplies the power from the distribution line 11 to each device of the light emitting device 14 and the light receiving device 19, but the power supply 23 is disconnected by disconnection of the distribution line 11 or switching of the transmission line by the switch 12. When the supply becomes impossible, the power supply is switched to the backup power supply battery 24 to supply the power. At this time, the power supply 23 sends a switching signal indicating that the backup power supply has been turned on to the light emitting device 14. When the power transmission of the distribution line 11 is resumed and the power supply from the distribution line 11 becomes possible, the power supply 23 switches the power supply to the distribution line 11 and stops the transmission of the switching signal.

FIG. 2 is a configuration diagram showing the configuration of the first embodiment of the light emitting device 14 and the light receiving device 16 for performing the upstream optical transmission shown in FIG. In the figure, the light emitting device 14 is
3. A clipping circuit 14a for clipping the analog state signal input from 3 and outputting a digitized signal
And periodic ON / OFF based on a switching signal from the power supply 23.
A signal generator 14b for generating a digital signal comprising OFF information, and a mixer 14 for mixing and multiplexing the two signals.
c and a light emitter 14d that emits an optical signal based on the multiplexed signal.

The clipping circuit 14a and the signal generator 1
If the fundamental frequencies of both signals output from 4b are close, the frequency components of both signals may overlap or cross-modulation may occur, making it difficult to identify the desired frequency. Therefore, in the present embodiment, the fundamental frequency of the digital signal output from the signal generator 14b is set to about several tens times the fundamental frequency of the signal output from the clipping circuit 14a, so that the frequency components of the two signals overlap. And mixing is performed while preventing the occurrence of cross modulation.

The light receiving device 16 includes a light receiver 16a for converting the received optical signal into an electric signal, a low-pass filter (LPF) 16b for reproducing a clipped digital signal from the electric signal into an original analog signal. , A band-pass filter (BPF) for extracting a multiplexed signal
16c and a peak detector 16d for detecting the presence or absence of the output of the BPF 16c and reproducing the multiplexed digital signal. In this embodiment, the LPF is used for reproducing the analog signal and the BPF is used for reproducing the multiplexed digital signal. However, the present invention is not limited to this. For example, when the frequencies of both signals are high, LPF to BP
It is also possible to change the F to F and the BPF to a high-pass filter.

Next, the operation of the present embodiment will be described with reference to the waveform diagrams of the respective parts in FIGS. In the present embodiment having the above configuration, as shown in FIG. 3A, for example, the state signal (analog signal) of the switch 12 composed of a modulation signal frequency-modulated or phase-modulated by a modulation method such as FSK or PSK is The signal is input from the slave station 13 to the clip circuit 14a, where it is clipped and converted into a digital signal (see FIGS. 3 (b) and 4 (b)). In addition, the signal generator 14 b
A periodic on / off digital signal is output based on the switching signal input from the controller (FIG. 4A and FIG. 5A).
reference). FIG. 4B is a waveform diagram in which the digital signal of FIG. 3B is enlarged along the time axis to show the relationship with the high-frequency digital signal of FIG.

The mixer 14c mixes both signals from the clip circuit 14a and the signal generator 14b by adding or multiplying them. That is, when the digital signal shown in FIG. 5A is input from the signal generator 14b, the mixer 14c converts the clipped digital signal into the signal generator 14b as shown in FIG. 5B. Are multiplexed and output. Further, as shown in FIG. 6A, the mixer 14c includes the signal generator 1
When there is no digital signal input from FIG.
As shown in (b), a signal having the same waveform as the clipped digital signal is output. FIGS. 5 and 6 are also waveform diagrams enlarged along the time axis. In addition, in the mixer 14c, when adding both signals, for example, an OR logic adder is used. When multiplying the two signals, for example, an AND logic multiplier can be used. Further, in FIG. 5B, the digital signal from the signal generator 14b is superimposed on the region of “0” of the clipped digital signal, but depending on the configuration of the mixer 14c, the “1” of the above signal is It is also possible to superimpose the digital signal from the signal generator 14b on the area.

The signal mixed by the mixer 14c is converted into an optical signal by the light emitter 14d, received by the light receiver 16a via the optical fiber 15, and converted into an electric signal.
It is input to the PF 16a and the BPF 16c. LPF16a
Then, the clipped digital signal is reproduced into the original analog signal as shown in FIG.
Then, the multiplexed digital signal is reproduced into the original digital signal as shown in FIGS. 5A and 6A,
The signal is identified by the peak detector 16d. The reproduced analog signal and digital signal are taken into the master station 20 via the metal cable 25 as distribution line monitoring control data.

As a result, in the present embodiment, F
An analog signal (modulated signal) based on a modulation method such as SK or PSK is converted into an optical signal and transmitted, and the receiving side reproduces the modulated signal and then sends it out to the master station. It can be used additionally. Further, in this embodiment, the modulated signal which has been clipped and digitized, and a digital signal comprising on / off information having a frequency different from the frequency of the modulated signal are mixed and transmitted, and both signals are reproduced on the receiving side. Therefore, optical multiplex transmission can be performed with a simple and inexpensive configuration.

FIG. 7 is a configuration diagram showing the configuration of a second embodiment of the light emitting device and the light receiving device for performing upstream optical transmission shown in FIG. In this embodiment, a gate circuit 14e is connected between the signal generator 14b and the mixer 14c, and the output of the digital signal from the signal generator 14b is controlled by a switching signal from the power supply 23. This allows
In the present embodiment, when a switching signal is generated, the gate is opened, the digital signal of the signal generator 14b is output to the mixer 14c, and the signal can be multiplexed. The gate is closed and the signal generator 14
The digital signal b can be prevented from being output to the mixer 14c.

Therefore, in the present embodiment, the digital signal output from the signal generator is controlled using a gate circuit whose production cost is lower than that of the first embodiment in which the signal generator is directly controlled, so that a further inexpensive configuration is achieved. Multiplex transmission. In these embodiments, the improved upstream optical transmission from the slave station to the master station is shown. However, the present invention is not limited to this, and the present invention is applied to the downstream optical transmission from the master station to the slave station. It is also possible to perform distribution line monitoring and control using the above system.

By the way, in the second embodiment, the signal generator 1
The output of 4b is input to the mixer 14c through a gate 14e that is opened and closed based on a switching signal input from the power supply 23, and is mixed with the output signal from the clip circuit 14a. In this case, the output of the signal generator 14b is mixed with the output signal from the clipping circuit 14a depending on the logic of the switching signal, and sometimes not mixed. That is, in the second embodiment, when the switching signal from the power supply 23 is on, the gate 14e can be opened to mix the output signal of the signal generator 14b with the output signal of the clipping circuit 14a. Is off, the gate 14e is closed, so that the output signal of the signal generator 14b is not mixed with the output signal of the clipping circuit 14a.

When the output of the signal generator 14b is mixed, the fundamental frequency component of the analog signal is halved compared to when the output is not mixed. The LPF 16b is used to extract an analog signal from the clipped digital signal, but the variation in the fundamental frequency component is directly reflected on the output amplitude of the LPF 16b, so the difference in output amplitude between superimposition and non-superposition (50%) Will occur. Therefore, in the second embodiment, an unnecessary dynamic range may be required for the analog signal demodulation circuit.

Therefore, in the third embodiment, the digital signal obtained by clipping the analog signal is added, for example, to the fundamental frequency f0 of the analog signal in accordance with the logic of the switching signal from the power supply 23.
One of the two frequencies f1 and f2, which is about 10 times apart from, ie, two frequencies f1 and f2 under the condition of f0 ≦ 10 × f1, f0 ≦ 10 × f2, f1 ≠ f2, is always mixed.

The two frequencies f1 and f2 correspond to the on or off state of the backup power supply, respectively. Specifically, as shown in FIG. 8, when the backup power supply signal is on, the gate 14e is opened to output the output of the signal generator 14b for generating the frequency f1, and when the backup power supply signal is off, the inverter 14g is turned off.
The gate 14f is opened with the switching signal whose logic is inverted by the above, and the output of the signal generator 14h for generating the frequency f2 is
Each is mixed with the output signal of the clip circuit 14a. Therefore, the output signal of the clip circuit 14a is always mixed with one of the frequencies f1 and f2 regardless of the logic of the switching signal. Of these two frequencies,
Which frequency is mixed can be identified by two BPFs corresponding to each frequency or a BPF passing only one frequency.

FIG. 8 shows an example in which a BPF 16c that passes only one frequency is provided in the configuration of this embodiment. Specifically, since the BPF 16c selectively passes only the frequency f1 from the output signal of the light receiver 16a, the digital signal from the peak detection circuit 16d is turned on only when the frequency f1 is mixed. When the frequency f2 is mixed, the output signal of the photodetector 16a does not pass through the BPF 16c, so that the digital signal from the peak detection circuit is turned off. As a result, a digital signal corresponding to the on / off state of the switching signal from the power supply 23 on the slave station side can be output to the master station 20.

In this embodiment, the frequency f2 is set to be about five times the frequency f1 in order to simplify the structure of the BPF 16c so that the frequency f1 can be selectively passed even if the selectivity is not so high. Set to. Further, the present invention is not limited to this, and it is of course possible to make the frequencies f1 and f2 closer to each other than in the third embodiment by increasing the selectivity of the BPF 16c.

As a result, in the third embodiment, the difference between the output amplitudes of the LPF can be almost reduced irrespective of the logic of the switching signal of the power supply, and even if the dynamic range of the FSK demodulation circuit is small, demodulation is not performed. , That is, it is difficult to require an unnecessary dynamic range. In the third embodiment, two signal generators corresponding to the frequencies f1 and f2 are provided. However, a single signal generator capable of switching and outputting the frequencies f1 and f2 is used to switch from the power supply. The frequencies f1 and f2 output by the signal generator may be switched according to the on / off state of the signal.

In the third embodiment, the correspondence between the logic (on and off) of the switching signal from the power supply and the frequencies f1 and f2 is merely an example, and the combination of the logic is limited to this embodiment. It is not something that can be done. Also, in the present invention, three or more signal generators and gates are provided on the slave station side, and the same number of BPFs are provided on the master station side, and different types of digital signals are output to the signal generators. It is also possible to superimpose and output to the master station. In this case, the gate opening / closing timing is determined by logic according to the number. As a result, not only the status signal from the clip circuit but also more types of information can be transmitted from the slave station to the master station.

[0031]

As described above, according to the present invention, a line device for setting a line of a distribution line and a line device connected to the line device and controlling the line device based on a control signal from a master station. > are both, in the distribution line monitoring and control system and a slave station which transmits the analog signal indicating the state of該線path devices to said master station, the slave station side, a first digital to clip the analog signal A clip circuit for generating a signal ,
The first digital signal has a large fundamental frequency.
Differently, a second data indicating a power supply mode to the line equipment is described.
A signal generator for generating a Ijitaru signal, and mixing means for mixing said second digital signal to said first digital signal, and emitting an optical signal based on the mixed signal
Provided an optical signal emitting means for sending to said master station, said parent station extracts light receiving means for receiving the optical signal, the analog signal from the optical signal receiving light and a second digital signal respectively Since the signal extracting means is provided , optical transmission can be performed with a simple and inexpensive configuration.

Further, according to the present invention, a power supply for the line equipment is provided.
As the second digital signal indicating the supply mode, the basic
Two kinds of digital signals f1, having different frequencies,
f2 is generated complementarily according to the power supply mode,
In the mixing means, complementary according to the power supply mode
One of the digital signals f1 and f2 generated
Since mixing constantly serial first digital signal, simple, and both to be able to perform optical transmission with an inexpensive configuration, the effect of such it is unnecessary to require unnecessary dynamic range to the demodulation circuit of the analog signal Kanade Can be done .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a schematic configuration of a distribution line monitoring and control system according to the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a first embodiment of a light emitting device and a light receiving device that perform upstream optical transmission illustrated in FIG. 1;

FIG. 3 is a waveform diagram of each unit shown in FIG.

FIG. 4 is a waveform chart of each unit shown in FIG. 2;

FIG. 5 is a waveform chart of each unit shown in FIG. 2;

FIG. 6 is a waveform chart of each unit shown in FIG. 2;

FIG. 7 is a configuration diagram showing a configuration of a second embodiment of the light emitting device and the light receiving device for performing the upstream optical transmission shown in FIG. 1;

FIG. 8 is a configuration diagram showing a schematic configuration of a third embodiment of the distribution line monitoring and control system according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Support 11 Distribution line 12 Switch 13 Slave station 14 and 17 Light emitting device 14a Clip circuit 14b and 14h Signal generator 14c Mixer 14d Light emitting device 14e and 14f Gate 14g Inverter 15, 18 Optical fiber 16, 19 Light receiving device 16a Light receiving device 16b Low-pass filter (LPF) 16c Band-pass filter (BPF) 16d Peak detector 20 Master station 21, 22, 25, 26 Metal cable 23 Power supply 24 Battery

Continued on the front page (72) Inventor Junichi Kasahara 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Katsunori Kurashima 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. In-company (72) Inventor Ryuji Uchino 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (56) References JP-A-4-190644 (JP, A) JP-A-6-104871 ( JP, A) JP-A-56-166735 (JP, A) JP-A-4-290020 (JP, A) JP-A-54-138305 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) H02J 13/00 H04J 14/00 H04J 14/02

Claims (2)

(57) [Claims] And the line equipment to set the lines 1. A distribution line is connected to該線path equipment, both by controlling the state of the line equipment based on the control signal from the master station, an analog signal indicating the state of該線path equipment And a slave station for sending the master station to the master station. The slave station side includes : a clipping circuit that clips the analog signal to generate a first digital signal ;
Its fundamental frequency differs greatly from digital signals.
A second digital signal indicating a mode of power supply to the track equipment
A signal generator for generating a first digital signal;
When a mixing means for mixing the second digital signal, the master station emits optical signals based on the <br/> mixed signal
An optical signal emitting means for sending, the master station side, receiving unit and a signal extracted from the optical signal receiving light separating said analog signal and a second digital signal respectively for receiving the optical signal A distribution line monitoring and control system comprising extraction means. 2. The signal generator according to claim 1 , further comprising:
The second digital signal indicating the source supply mode is
Two types of digital signals f having different main frequencies
1, f2 are generated complementarily according to the power supply mode.
Be those, wherein mixing means are complementarily raw according to the power supply form
One of the digital signals f1 and f2 generated is
2. A signal which is always mixed with one digital signal.
3. The distribution line monitoring and control system according to 1.