JPH01284774A - Optical monitor system - Google Patents

Abstract

PURPOSE:To easily form the monitor system for monitoring the state of an observed point by connecting a monitor terminal equipment to an optical input/ output device only when necessary and controlling the transmitting operation of the monitor terminal equipment under the control of a center monitor station. CONSTITUTION:Light signal input/output devices 7 consisting of only passive elements are interposed at respective predetermined points on an optical transmission line consisting of an optical fiber. Portable monitor terminal equipments 10 are installed at necessary points nearby the devices 7. A master station 20 which receives data information and monitor information sent through the optical transmission line 5' and performs prescribed processing to grasp the states of monitored points is provided at one end of the optical transmission line 5'. The devices 10 are connected to the equipments 7 through optical cords 50a and 50b when necessary. Consequently, the monitor system which has high cost performance and becomes able to operate only when necessary is easily constituted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a system configuration for monitoring power supply lines such as overhead power transmission and distribution lines and power lines, and particularly to a system configuration for monitoring power supply lines only when necessary. Regarding system configuration.

[Prior Art] For example, in a power supply line such as an overhead power transmission line,
When an accident such as a ground fault or short circuit occurs, it is necessary to promptly deal with the accident, so a system for monitoring the state of power transmission lines as shown in FIG. 5 has been used conventionally.

In FIG. 5, three steel towers 1a are representative.

1b and IC are exemplified. The steel tower 1a includes, for example, a sensor 2a that detects power transmission line current information at the location of the steel tower 1a, and a junction box (transmission terminal) that receives a detection signal from the sensor 2a, performs predetermined processing, and sends it out.
3a, and an optical fiber junction box 4a for transmitting information from the junction box 3a in the form of an optical signal.

Junction boxes 3a to 3C and connection boxes 4a to 4c
are connected to each other by optical cables 9. Similarly,
Sensors 2b are also installed on the steel towers 1b and lc.

2 C% junction box 3b, 3c, junction box 4
b and 4c are provided, respectively. The connection boxes 4a to 4C are
Connect the optical fibers included in each 0PGW (optical fiber composite overhead ground wire) 5 to the corresponding junction box 3a~
Connect to the optical fiber that becomes the transmission path for the signal from 3C.

Signals transmitted via optical fibers included in 0PGW5 are sent to a central monitoring station. Next, the operation will be briefly explained.

Each of the sensors 2a to 2c detects the current flowing through the overhead ground wire included in the 0PGW 5, for example, and provides detection information to the corresponding jack boxes 3a to 3c. Each of the junction boxes 3a to 3C performs predetermined processing (for example, detection of current value information and current phase information) on the ground wire current information sent from the corresponding sensor, and transmits the processing results from the preceding junction box. Multiplex the derived processing information and send it to the next junction box.
It is sent out via an optical fiber included in the PGW 5. As a result, the current information detected by each sensor 2a to 2c is 0PG.
It is sent to the central monitoring station via an optical fiber included in W5. The central monitoring station monitors the power transmission line current information detected by each sensor sent from each junction box, and monitors whether or not an abnormality is occurring in the power line, and where the abnormality is occurring when an abnormality occurs. .

[Problems to be Solved by the Invention] As mentioned above, in conventional monitoring systems, for example, in the case of a system that monitors power transmission line current, the information is processed to become power transmission line current information and then sent to a central monitoring station. It was necessary to provide a junction box for this purpose, and configure the signal processing section and signal transmission terminal device of this junction box using an active circuit and a power supply, and it was necessary to constantly send out power transmission line current detection information.

However, depending on the type of maintenance monitoring of overhead power transmission lines, for example, it may not be necessary to constantly or permanently send monitoring information to the central monitoring station.

For example, when an accident occurs, a telephone contact is made between a supervisor dispatched to the scene and a central monitoring station located, for example, in a substation. Communication between the site and the central monitoring station for monitoring construction work being carried out near power lines using cranes, etc. Observation of snow cover (or snow cap) on power transmission lines and towers, which is only necessary in winter.

In these cases, it is only necessary to send information to a central monitoring station on a temporary or seasonal basis, and it is cost-effective to provide a transmission terminal that requires active circuits and power supplies specifically for this purpose. This makes the system inefficient.

Therefore, in order to deal with the above-mentioned case, a system in which transmission terminals are installed on-site only when necessary and information is exchanged with a central monitoring station is desirable from the viewpoint of cost performance.

Therefore, an object of the present invention is to provide a monitoring system with a simple configuration and excellent cost performance, which can establish an information exchange system with a central monitoring station only when necessary.

[Means for Solving the Problems] An optical monitoring system according to the present invention includes an optical transmission line made of an optical fiber, and is inserted into each of a plurality of predetermined points on the optical transmission line, and outputs an optical signal. optical signal input means consisting only of passive elements, and equipment-specific information that is installed at the site and coupled to the corresponding optical signal input/output means when necessary, and sent from the central monitoring station via the optical transmission line. It consists of a portable monitoring terminal device that responds by sending an optical signal onto the optical transmission path.

[Function] The optical signal input means inserted into the optical transmission line is composed only of passive elements such as optical branchers and optical multiplexers and demultiplexers, so an operating power source is not required and the terminal terminal device is Since it is portable, it can be installed on-site only when necessary, and since monitoring information is sent out under the control of a central monitoring station, it is possible to construct a highly cost-effective monitoring system that can be operated only when necessary.

[Embodiment of the Invention] FIG. 1 is a diagram showing a schematic configuration of an optical monitoring system that is an embodiment of the present invention. Optical transmission line 5 made of optical fiber
An optical signal input/output device 7 consisting of only passive elements is inserted at each of a plurality of predetermined points, and a portable monitoring terminal device 10 is installed at a necessary point near the optical signal input/output device 7. be done.

A master station 20 is provided at one end of the optical transmission line 5' for receiving data information and monitoring information transmitted via the optical transmission line 5' and performing predetermined processing to grasp the status of the monitored point. It will be done. The master station 20 includes a display device (CRT) 21 for monitoring video information sent from monitored points, and performs predetermined processing on the transmitted data information to display information indicating the status of each monitored point. An information processing device 22 made of, for example, a computer is provided for deriving the information. The optical transmission line 5' is composed of, for example, a single-mode optical fiber or a multi-mode optical fiber in order to wavelength-multiplex and transfer information. The master station 2o transmits the terminal device specific information modulated with wavelength λ1, and each terminal device 1o emits light only when the device specific information sent from the master station 2o specifies its own station. It becomes possible to send information, and the wavelength λ
The monitoring information modulated in step 2 is sent out. For the optical transmission line 5' used in a monitoring system that becomes operational only when necessary, it is necessary to reduce the number of optical fibers as much as possible from the viewpoint of cost performance, etc., and in this embodiment, bidirectional A single-core optical fiber is used.

FIG. 2 is a diagram schematically showing the configuration of the main parts of the optical monitoring system shown in FIG. 1, and shows the configuration within the broken line block shown in FIG. 1. In FIG. 2, the optical transmission line 5'
is combined into 0PGW5.

The optical input/output device 7 connects the optical transmission line 5 with the optical fiber connection box 4.
′ is inserted in series. As the optical fiber junction box 4,
For example, an optical fiber junction box provided corresponding to a steel tower as shown in FIG. 5 is used. The optical transmission line 5' is fusion-spliced at a connection point 40 within the connection box 4. The optical input/output device 7 and the junction box 4 are connected by an optical cable 9 in order to perform optical signal communication using the optical transmission line 5'. Optical transmission line 5'
The branch path is provided by the optical cable 9.

The optical input/output device 7 includes an optical combiner/brancher 71 for branching and combining applied optical signals, and an optical combiner/brancher 7.
an optical wavelength multiplexer/demultiplexer 72 that demultiplexes the optical signal from 1 according to the wavelength and wavelength-multiplexes the optical signal given from the monitoring terminal 10; and an interface for exchanging optical signals with the monitoring terminal 10; Optical connectors 73a and 73b
Equipped with. The operation of the optical combiner/brancher 71 is basically as shown in FIG. At the same time, the optical signals from the optical wavelength self-wavelength filter 72 are combined and sent onto the optical transmission line 5'. Therefore, when the intensity of the optical signal given from the optical transmission line 5' is Po, the optical combiner/brancher 71 has the same intensity, that is, the intensity P.

/2 optical signals, combines the optical signals given from each device, and sends out an optical signal with an intensity equal to the sum of the combined optical signal intensities. The optical wavelength multiplexer/demultiplexer 72 receives the optical signal given from the optical combiner/brancher 71, and as shown schematically in FIG. ) and wavelength λ2 (control information sent from the master station), and each optical connector 73a, 7
3b, and optical connectors 73a, 7
The optical signal from 3b is wavelength-multiplexed and sent to the optical combiner/brancher 71. In the configuration shown in FIG. 2, an example is shown in which the optical connector 73a serves as an interface portion for a signal with a wavelength λ2, and the optical connector 73b serves as an interface portion for a signal with a wavelength λ1. Between the first input/output device 7 and the terminal monitoring device 10 is an optical cord with a connector 50a,
50b. Optical connectors 51a and 52b are provided at both ends of the optical cord 50a, respectively.
Optical connectors 51b are provided at both ends of the optical cord 50b.

52b are provided respectively. The optical code 50a is used to transmit control information modulated with a wavelength λ2 given from the master station, and the monitoring information modulated with a wavelength λ1 given from the monitoring device 10 is transmitted to the optical code 50b.

The monitoring terminal device 10 includes optical connectors 101a and 101b serving as an interface section for optical signals, and an optical connector 101.
an optical-to-electrical converter 102 for receiving an optical signal of wavelength λ2 given from a and converting it into an electrical signal; a storage device 103 for storing device specific information assigned to the monitoring terminal device 10; - A decoder 104 that detects a match or mismatch between the device specific information constituted by the electrical converter 102 and the device specific information stored in the storage device 103, and a decoder 104 that captures an image of the situation near the installation point of the monitoring terminal device 10 and derives a video signal. For example, an ITV (industrial television camera) 105, a sensor 106 that detects information on a predetermined object to be measured, a multiplexer 108 that receives and multiplexes monitoring information via a signal terminal 107, and multiplexed information by the multiplexer 108. In response to the coincidence detection signal from the decoder 104, the ten electrical-to-optical converters for converting electrical signals into optical signals are brought into conduction state, and the optical signals from the electrical-to-optical converters 109 are connected to each other through the optical connector 101b. and a switch 110 configured using, for example, an optical switch, which sends the signal to the optical input/output device 7 side. Next, the operation will be briefly explained.

In a state where this monitoring system is not required, the monitoring terminal device 10 is not provided, and the optical input/output device 7 is simply inserted in series in the optical transmission line 5' combined with the 0PGW 5. . Since the optical input/output device 7 is composed only of passive elements consisting of an optical combiner/brancher 71 and an optical wavelength multiplexer/demultiplexer 72, it does not require any power source for its operation and is simply used for inputting and outputting optical information. The connector part is now installed.

When necessary, the portable monitoring terminal device 10 is connected to the optical input/output device 7 via optical cords 50a and 50b.

The monitoring terminal device 10 operates by being supplied with operating power from a power source 111. ITV1 provided in the terminal monitoring device 10
05 images the situation near the device 10 and provides the video information to the multiplexer 108 via the connector 107. On the other hand, the sensor 106 derives a detection signal indicating the operating status of a predetermined object to be measured, and supplies it to the multiplexer 108 via the connector 107. The electrical signal from the multiplexer 108 is given to an electrical-optical converter 109, where it is converted into an optical signal of wavelength λ1.

Now, when device specifying information (address signal) for specifying the device is sent from the central monitoring station (Fig. 1, 20) onto the optical transmission line 5' by a signal with wavelength λ2, this device specifying information is transferred to the optical input/output device. 7. Provided to the optical-to-electrical converter 102 of the terminal monitoring device 10 via the optical cord 50a. The decoder 104 is
Upon receiving the device identification information from the optical-to-electrical converter 102,
It is compared with the device specific information stored in the storage device 103, and a mismatch is detected. If the decoder 104 detects a match in the device identification information, this indicates that the terminal device 10 is being accessed from a central monitoring station, and in response to the decoder 104 output, the switch 110 becomes conductive (conducting) and the electrical The optical signal with the wavelength λ1 changed by the optical converter 109 is given to the optical input/output device 7 via the optical cable 50b. The signals are multiplexed and given to the optical combiner/brancher 71.The optical combiner/brancher 71 is the optical wavelength multiplexer/demultiplexer 7.
The optical signals from 2 are combined and sent onto the optical transmission line 5' via the optical cable 9. At the central monitoring station, the optical signal sent via the optical transmission line 5' is received, and the monitor television (CRT) 21 included therein monitors the video information sent from the ITV 105, and the video information derived from the sensor 106 is monitored. The sensor information is subjected to predetermined processing to monitor the situation at the monitoring point. With the above-described configuration, only the terminal device 10 designated by the device specifying information from the central monitoring station becomes capable of transmitting an optical signal and becomes capable of communicating with the central monitoring station. In other terminal devices 10, the device specific information does not match the device specific information provided in the device, so the switch 1
10 remains in a non-communicable state because it is in a non-conductive state.

When accessing a predetermined monitoring terminal device 10, the central monitoring station 20 communicates with the corresponding terminal device 10 by sequentially transmitting device identification information preset for each device onto the optical transmission line 5'. It becomes possible. This makes it possible to monitor the situation at each location by receiving information about each location detected by each terminal device 10.

Now, the number of optical input/output devices that can be installed when using a single mode optical fiber will be explained using specific numerical values. Now, the wavelength λ1 of the optical signal sent by each terminal device 10 is 1.3 μm, the wavelength λ2 of the optical signal of the control information sent by the central monitoring station is −1.55 μm, a laser diode is used as the light source, and an APD is used as the light receiving element.
A case where an avalanche photodiode (avalanche photodiode) is used will be explained.

Now, the insertion loss that occurs when an optical combiner/brancher is inserted into an optical fiber transmission line is 3.5 dB.

The insertion loss when an optical wavelength multiplexer/demultiplexer is inserted into an optical fiber transmission line is 0.5 dB.

Optical fiber transmission loss is 0.5dB/Km.

The emission output of the laser diode is -5 dBm.

The light receiving power of the APD is -50 dBm.

3dB system margin.

Let N be the maximum number of nodes configured when installing optical input/output devices, and assuming a 20 Km power transmission line as an optical fiber transmission line, [-(-50)-31 > 3.5XM + 0.5 + 20XO05 Therefore, 9≧N1, and using the above system parameters, 20
It becomes possible to provide input devices at a maximum of nine locations along a power transmission line of Km.

As mentioned above, the optical input/output device is composed only of passive elements such as the optical combiner/brancher and the optical wavelength multiplexer/demultiplexer, so there is no need for a power source for its operation, and the device configuration can be made inexpensive. , easy to maintain.

Furthermore, since the monitoring terminal device is portable, it is possible to easily configure a system that is used only when necessary, and the cost performance of the system can be improved.

Furthermore, by providing an optical input/output device in advance at a predetermined point on the optical transmission line 5' corresponding to the point where the monitoring terminal device 10 is installed, there is no need to newly install an optical input/output device as necessary. , it is possible to configure a highly flexible and cost-effective monitoring system.

In addition, in the above-described configuration, the 00000000 is provided corresponding to the steel tower as a connection box for connecting the optical fiber transmission line 5'.
If a junction box for connecting the optical fibers included in the PGW 5 is used, there is no need to provide a new junction box, and the system can be easily configured.

Furthermore, by installing the optical input/output device 7 in a junction box that has been conventionally provided for steel towers, it is possible to add a new monitoring system that operates only when necessary using the conventional monitoring system. A monitoring system with excellent cost performance, flexibility, and ease of device configuration can be constructed.

In the above embodiment, the optical transmission line 5' is configured to be combined with the 0PGW provided on the overhead power transmission line and transmitted, but for example, in order to monitor the power line installed underground, By providing an optical transmission line 5' in parallel with the existing monitoring system, it becomes possible to provide a monitoring system for the power line as well, which operates only when necessary for the product.

[Effects of the Invention] As described above, according to the present invention, an optical input/output device consisting only of passive elements and operating without a power supply is provided at a predetermined point of an optical transmission line, and this optical input/output device is operated only when necessary. A monitoring terminal device is connected to the device, and the transmission operation of the monitoring terminal device is controlled under control from a central monitoring station. In monitoring systems for power lines in distribution lines and tunnels, etc.
It is possible to configure a monitoring system to monitor the status of the observation point only when necessary, and it is possible to realize an optical=m system that is excellent in terms of flexibility, equipment configuration, cost performance, and maintenance. can.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing an example of the configuration of an optical monitoring system that is an embodiment of the present invention. FIG. 2 is a diagram schematically illustrating a schematic configuration of an optical input/output device and a monitoring terminal device used in an optical monitoring system that is an embodiment of the present invention, and an example of their connection form. FIG. 3 is a diagram illustrating the principle of the operation of the optical combiner/brancher. FIG. 4 is a diagram showing the principle of operation of an optical wavelength multiplexer/demultiplexer. FIG. 5 is a diagram showing an example of the configuration of a power transmission/distribution line monitoring system using a conventionally used 0PGW. In the figure, 4 is an optical fiber junction box, 5 is 0PGW, 5
' is an optical transmission line, 7 is an optical input/output device, 10 is a monitoring terminal device, 20 is a central monitoring station, 50a and 50b are optical cords,
71 is an optical combiner/brancher, 72 is an optical wavelength multiplexer/demultiplexer, 103
104 is a decoder, 108 is a multiplexer, 110 is a switch, and 111 is a power supply. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. 20th

Claims (1)

[Claims] A system for monitoring the state of a predetermined point along a power supply line, comprising: an optical transmission line that transmits information in the form of an optical signal; and a plurality of children of the optical transmission line. A means for inputting and outputting optical signals, which is inserted at each predetermined point and consists of only passive elements, and a means for inputting and outputting optical signals, which is provided at a predetermined point of the power supply line only when necessary, and is inserted into a corresponding optical signal input and output means. a portable monitoring terminal device which is coupled to monitor the state of the point and sends the monitoring information onto the optical transmission path via a corresponding optical signal input/output means; a master station that includes information processing means for transmitting information identifying a terminal device onto the optical transmission path and performing predetermined processing on monitoring information received via the optical transmission path, further comprising: means for storing self-identifying information; means for detecting coincidence/mismatch between the specific information transmitted from the master station and the specific information stored in the storage means; and a coincidence signal from the detection means. an optical monitoring system comprising means for providing monitoring information derived by the terminal device in response to the corresponding optical signal input/output means.