JPH1019939A - Protective control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the realization of a multiple system even when sensors detecting a state of an object of measurement are constructed of single ones respectively. SOLUTION: A current flowing through a transmission line 14 is converted into an optical signal by an optical CT sensor 16 and this optical signal is transmitted to an optical branch unit 24 through an optical fiber 22. The optical branch unit 24 makes the optical signal from the optical fiber 22 branch into optical signals of two systems and transmits the optical signals to system relays 34 and 36 through optical fibers 30 and 32. The system relays 34 and 36 outputs trip commands for tripping a breaker 26, when a voltage detected by an optical PT sensor 12 and the current detected by the optical CT sensor 16 exceeds set values respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection control system, and more particularly to a protection control system suitable for converting the state of a power system into an optical signal and protecting the power system based on the optical signal.

[0002]

2. Description of the Related Art As a power system protection control system, a voltage of a power system is introduced through a transformer for an instrument, and a current of the power system is introduced through a current transformer for an instrument. It is known that when the value exceeds the limit, a circuit breaker of the system is cut off assuming that an abnormality has occurred in the system. When adopting such a protection control system in an electric power system, for example, in a system of 275,000 volts or more, a system of two systems is adopted. That is, an instrument transformer is arranged in the system, two current transformers are arranged, and two system relays for judging whether the system is abnormal based on the outputs of the transformer and each current transformer are arranged. ,
A system has been adopted which protects the power system by reliably detecting an abnormality in the power system even when one of the protection control systems fails.

In recent years, in place of a current transformer for an instrument, for example, as described in Japanese Patent Publication No. 4-76068, an optical system for converting a current signal into an optical signal in response to a current flowing through a system. Attempts have been made to employ an electromagnetic measurement device of the type described above. The use of an optical electromagnetic measurement device can reduce the size compared to the case of using a current transformer for an instrument.

[0004]

In the prior art, the protection control system for the power system is divided into two systems, and if one system fails, the other system protects the system. Since two devices must be arranged, the system configuration becomes complicated. Further, even if an optical electromagnetic measurement device is used instead of the current transformer for the instrument, it is not possible to achieve two lines by simply using one optical electromagnetic measurement device.

An object of the present invention is to provide a protection control system capable of achieving multi-system even if a single sensor for detecting the state of a protection target is configured.

[0006]

In order to achieve the above object, the present invention provides a light-to-light conversion sensor for converting an electric signal into an optical signal in response to an electric signal to be measured and a plurality of outputs of the light-to-light conversion sensor. Optical splitter that splits into optical signal transmission systems, and a plurality of protection control information generators that take in optical signals from each optical signal transmission system of the optical splitter and generate protection control information on a protection target based on each optical signal. And a protection control system comprising:

In adopting the above protection control system, the following elements can be added.

(1) Each protection control information generator determines whether or not an abnormality has occurred in a protection target from an output of the photoelectric converter that converts an optical signal into an electric signal, and protects the result of the determination. A determination circuit that outputs as control information; an abnormality detection circuit that compares the output of the photoelectric converter with a set value to detect an abnormality in the optical signal transmission system; and outputs an abnormality determination of the determination circuit based on the abnormality detection of the abnormality detection circuit. And an abnormality determination output prohibition circuit for forcibly prohibiting the operation.

(2) Light connecting the light-to-light conversion sensor and the protection control information generator based on the output of the abnormality detection circuit of one protection control information generator and the output of the abnormality detection circuit of the other protection control information generator An abnormal point determining circuit for determining an abnormal point in a portion related to the signal transmission system is provided. (3) The abnormal point determining circuit is configured to output one of the protection control information generators when an abnormality is detected only from the abnormality detection circuit. The protection control information generator outputs a determination result indicating that an abnormality has occurred in a portion between the input side of the photoelectric converter and the output side of the optical splitter connected to the photoelectric converter, and outputs the protection result of the other side. When an abnormality detection is output only from the abnormality detection circuit of the control information generator, the abnormality is detected between the input side of the photoelectric converter of the other protection control information generator and the output side of the optical splitter connected to this photoelectric converter. Indicates that an abnormality has occurred in the site Output the judgment result, and when the abnormality detection circuit of both protection control information generators outputs an abnormality detection, the optical splitter connected to both protection control information generators and the lightning device connected to the optical splitter A determination result indicating that an abnormality has occurred in a portion between the conversion sensor and the conversion sensor is output.

The present invention also provides a plurality of current light-to-light conversion sensors for converting a current into an optical signal in response to a current signal among electric signals to be measured, and a voltage signal among electric signals relating to a protection object. A plurality of voltage light-to-light conversion sensors for converting a voltage to an optical signal; a plurality of current light splitters for branching the output of each current light-to-light conversion sensor to a plurality of light signal transmission systems; and each voltage light-to-light conversion sensor A plurality of voltage optical splitters for splitting the output of each of the plurality of optical signal transmission systems,
A plurality of current protection control information generators that take in optical signals from each optical signal transmission system of each current optical splitter and generate protection control information on a protection target based on each optical signal, and each voltage optical splitter And a plurality of voltage protection control information generators that take in each optical signal from each optical signal transmission system and generate protection control information on a protection target based on each optical signal. .

In configuring a protection control system having respective protection control information generators for current and voltage, elements for current and voltage are added as the elements shown in the above (1) to (3). Can be.

According to the above-mentioned means, the output of the electro-optical conversion sensor for detecting the state of the protection target is split into a plurality of optical signal transmission systems by the optical splitter, and the output of the protection target is determined based on the optical signal of each optical signal transmission system. Since the protection control information regarding the protection target is generated, even if a single sensor is used to detect the state of the protection target, it is possible to increase the number of systems. Further, since the light-to-light conversion sensor and the optical branching device are constituted by passive elements, a highly reliable system without an electric failure mode can be realized.

On the other hand, with respect to the mechanical failure mode of the optical signal transmission system connecting the light-to-light conversion sensor and each protection control information generator, the abnormal part is specified by the abnormal part determination circuit, so that the system is abnormal. Even if the error occurs, the system can be quickly recovered from the abnormal state. Further, when the optical signal transmission system becomes abnormal, the output of the abnormality determination circuit forcibly prohibits the output of the abnormality determination of the determination circuit by the output of the abnormality detection circuit.
It is possible to prevent unauthorized response of the system.

[0014]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a protection control system according to an embodiment of the present invention. In FIG. 1, the protection control system is adopted in, for example, an electric power system of 275,000 volts or more to achieve multi-system, and a bus 10
To PT (Potential Transforme)
r) A sensor 12 is installed, and an optical CT (Current Transform) is applied to a transmission line 14 branched from the bus 10.
er) 16 is provided. The optical PT sensor 12 is configured as a voltage electro-optical conversion sensor that converts a voltage signal into an optical signal in response to an electric signal of the bus 10, for example, a voltage signal, with the bus 10 as a measurement target.
An optical splitter 20 is connected to the output side of 2 via an optical fiber 18. The optical CT sensor 16 is configured as a current light-to-light conversion sensor that converts a current signal into an optical signal in response to an electric signal, for example, a current signal flowing through the power transmission line 14 with the transmission line 14 as a measurement target. Sensor 16
An optical splitter 24 is connected via an optical fiber 22 to the output side. Note that a circuit breaker 26 is inserted in the transmission line 14 connected to the load.

The optical splitter 20 is configured as a voltage optical splitter for splitting an optical signal from the optical fiber 18 into two optical signal transmission systems. 28 are connected. The optical splitter 24 is configured as a current optical splitter for splitting an optical signal from the optical fiber 22 into two optical signal transmission systems. Optical fibers 30 and 32 are provided on the output side of the optical splitter 24. It is connected. The optical fiber 26 is connected to a system relay 34 as one optical signal transmission system, and the optical fiber 28 is connected to a system relay 36 as another optical signal transmission system.
The optical fiber 30 is connected to a system relay 34 as one optical signal transmission system, and the optical fiber 32 is connected to a system relay 36 as the other optical signal transmission system.

The system relay 34 includes optical fibers 26, 3
It is configured as a first protection control information generator that generates protection control information on a protection target such as the transmission line 14 based on the optical signal from 0, and the system relay 36 converts the optical signal from the optical fibers 28 and 32 into It is configured as a second protection control information generator that generates protection control information on a protection target based on the information. Each system relay 34, 36 is connected to the transmission line 1
4 is a protection target, a voltage signal detected by the optical PT sensor 12 and an optical signal corresponding to a current signal detected by the optical CT sensor 16 are respectively taken in, and the detected voltage exceeds the set voltage or the detected current exceeds the set current. In such a case, protection control information (shutdown command, trip command) for shutting off the circuit breaker 26 is generated. Each of the system relays 34 and 36 includes a current protection control information generator and a voltage protection control information generator. FIG. 2 shows a specific configuration of the current protection control information generator.

The current protection control information generators 38 and 40 include photoelectric converters 42 and 44, determination circuits 46 and 48, abnormality detection circuits 50 and 52, and logic gates 54 and 56, respectively.

The photoelectric converters 42 and 44 are configured as photoelectric conversion means for converting optical signals from the optical cables 30 and 32 into electric signals, respectively.
6, and 48 are input to the abnormality detection circuits 50 and 52.
The determination circuits 46 and 48 compare the electric signal from the photoelectric converters 42 and 44 with the current set value, and when the electric signal exceeds the current set value, output “1” as an abnormality determination output indicating an abnormal state of the protection target. Is output to the logic gates 54 and 56, respectively. Abnormality detection circuit 5
Reference numerals 0 and 52 compare the electric signals from the photoelectric converters 42 and 44 with a set value (threshold value), and determine that an abnormality has occurred in the optical signal transmission system when the level of the electric signal exceeds the set value. It is configured to output a 1 "signal to the logic gates 54 and 56.

The logic gates 54 and 56 receive the signals from the determination circuits 46 and 48 as they are, invert the signals from the abnormality detection circuits 50 and 52, and input the inverted signals. And an abnormality determination output prohibition circuit. That is, when the signal of “1” is output from the determination circuits 46 and 48 and the signal of “0” is output from the abnormality detection circuits 50 and 52, “1” is provided as protection control information indicating that an abnormality has occurred in the protection target. Is output. This signal is used as a cutoff command for tripping the circuit breaker 26. On the other hand, when the "1" signal is output from the abnormality detection circuits 50 and 52, the "0" signal is output from the logic gates 54 and 56 even if the "1" signal is output from the determination circuits 46 and 48. When an abnormality occurs in the optical signal transmission system, the judgment circuit 4
Even if the signal of "1" indicating the result of the abnormality determination is output by the signals 6 and 48, the output of the abnormality determination is forcibly prohibited. That is, when an abnormality in the optical signal transmission system is detected by the abnormality detection circuits 50 and 52, the outputs of the logic gates 54 and 56 are forcibly set to "0" and the determination circuit 4
6, 48. When an abnormality in the optical signal transmission system is detected by the abnormality detection circuits 50 and 52, the output of the abnormality detection circuits 50 and 52 is input to the abnormality part determination circuit 58 shown in FIG. .

The abnormal part judging point 58 is the AND gate 6
0, an abnormality alarm output circuit 62, 64, 66.
Is input to one of the input terminals and the abnormal alarm output circuit 62,
The output of the abnormality detection circuit 52 is input to the other input terminal of the AND gate 60 and the abnormality alarm output circuit 66. The output of the AND gate 60 is input to the abnormality alarm output circuit 64. The AND gate 60 is connected to the abnormality detection circuit 50,
52 is configured as a logic gate that outputs a signal according to the logical product of the outputs of the outputs 52 to the abnormality alarm output circuit 64. When the signal of “1” is output from the abnormality detection circuit 50, the abnormality alarm output circuit 62
An alarm output indicating that an abnormality has occurred in the optical signal transmission system including the optical cable 22, the optical splitter 24, and the optical cable 30 is generated. When the outputs of the abnormality detection circuits 50 and 52 both become “1”, the abnormality alarm output circuit 64 performs an AND operation.
When the output of the gate 60 becomes "1", the optical CT sensor 16, the optical cable 22, the optical splitter 24, and the optical cable 3
An alarm output indicating that an abnormality has occurred in the optical signal transmission system including 0 and 32 is generated. When the output of the abnormality detection circuit 52 becomes “1”, the abnormality alarm output circuit 66 outputs the optical CT sensor 16, the optical cable 22, and the optical branching device 2.
4. An alarm output indicating that an abnormality has occurred in the optical signal transmission system including the optical cable 32 is generated.

By monitoring the determination result of the abnormal part determination circuit 58, it is possible to specify that an abnormality has occurred in each optical signal transmission system when an abnormality has occurred in the two optical signal transmission systems.

An abnormality determination circuit 68 shown in FIG. 4 can be used as the abnormality location determination circuit. The abnormal part determination circuit 68 includes an AND gate 70, logic gates 72 and 7,
4. An abnormality alarm output circuit 76, 78, 80 is provided, and the output of the abnormality detection circuit 50 is
0 is input to one input terminal of the logic gate 72, and the output of the abnormality detection circuit 52 is input to the other input terminal of the AND gate 70 and one input terminal of the logic gate 74. The output of the AND gate 70 is input to the other input terminals of the logic gates 72 and 74, and is also input to the abnormality alarm output circuit 78. The outputs of the logic gates 72 and 74 are output from the abnormality alarm output circuit 7 respectively.
6, 80.

The AND gate 70 is connected to the abnormality detecting circuits 50, 5
A signal according to the logical product of the two output signals is output. The logic gate 72 receives the signal from the abnormality detection circuit 50 as it is, and inverts the signal from the AND gate 70 and inputs the inverted signal. The logic gate 74 inverts the signal from the AND gate 70 and inputs the signal, and also receives the signal from the abnormality detection circuit 52 as it is, and outputs a signal according to the logical product of the input signals. That is, the logic gate 72 outputs a signal of “1” when only the output of the abnormality detection circuit 50 becomes “1”, and outputs a signal of “0” otherwise. The logic gate 74 is connected to the abnormality detection circuit 52
Outputs a signal of "1" only when the output of "1" becomes "1", and outputs a signal of "0" otherwise. That is, when the outputs of the abnormality detection circuits 50 and 52 both become "1" and the output of the AND gate 70 becomes "1", the outputs of the logic gates 72 and 74 are forced to "0". It is configured.

The abnormal alarm output circuit 76 outputs an abnormal alarm indicating that an abnormality has occurred in the optical signal transmission system only when the output of the logic gate 72 becomes "1". The abnormality alarm output circuit 78 outputs an abnormality alarm indicating that an abnormality has occurred in the optical signal transmission system when the output of the AND gate 70 becomes "1". Further, the abnormality alarm output circuit 80 outputs an abnormality alarm indicating that an abnormality has occurred in the optical signal transmission system only when the output of the logic gate 74 becomes "1". When an abnormality alarm is output from the abnormality alarm output circuit 76, it is possible to specify that an abnormality has occurred in a portion of the optical signal transmission system including the optical splitter 24, the optical cable 30, and the photoelectric converter 42. When an abnormality alarm is output from the abnormality alarm output circuit 80, it can be specified that an abnormality has occurred in a portion of the optical signal transmission system including the optical splitter 24, the optical fiber 32, and the photoelectric converter 44. Further, the abnormal alarm output circuit 78
When an abnormality alarm is output from the
Since the abnormality is detected by both 0 and 52, the optical sensors 16, which are detection targets common to the abnormality detection circuits 50 and 52,
It is possible to specify that an abnormality has occurred in a portion of the optical signal transmission system including the optical fiber 22 and the optical splitter 24.

An abnormality in the optical signal transmission system is caused, for example, by a failure such as disconnection of the cores of the optical fibers 22, 30, and 32 or a poor connection of a connector. The abnormality caused by the mechanical failure mode of the optical signal transmission system can be recovered at an early stage.

In the above embodiment, the protection control information generator for current has been described. However, the protection control information generator for voltage can be configured in the same manner as the protection control information generator for current. In this case, the determination circuit is configured to compare the input signal with the voltage set value. Further, in this case, by connecting the abnormal part determination circuit 58 or 68 to the output side of the voltage protection control information generator, the optical PT sensor 12, the optical fiber 18, the optical splitter 2
0, it is possible to identify an abnormal part due to a mechanical failure mode of the optical signal transmission system including the optical fibers 26 and 28 and the photoelectric converter.

[0028]

As described above, according to the present invention,
Even if the sensor for detecting the state of the measurement target is configured as a single sensor, the output of the sensor for detecting the state of the measurement target is converted into an optical signal, and the optical signal is branched into a plurality of optical signal transmission systems.
Since the protection control information about the protection target is generated based on the optical signal of each optical signal transmission system, a multi-system can be realized even if a single sensor is used to detect the state of the measurement target. be able to. Further, when an abnormality occurs in the optical signal transmission system, the generation of the abnormality determination output of the protection target generated based on the optical signal is forcibly prohibited, so that the system can be prevented from being illicitly responded. In addition, because an abnormal alarm is output according to the logic of the detection output of the abnormal detection circuit, an abnormal portion of the optical signal transmission system can be identified according to the content of the abnormal alarm, and the abnormality caused by the abnormality of the optical signal transmission system can be specified. Recovery work can be performed quickly.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a protection control system according to an embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a system relay.

FIG. 3 is a circuit configuration diagram of an abnormal part determination circuit.

FIG. 4 is a circuit configuration diagram of another abnormal portion determination circuit.

[Explanation of symbols]

Reference Signs List 10 bus 12 optical PT sensor 14 transmission line 16 optical CT sensor 18, 22, 26, 28, 30, 32 optical fiber 20, 24 optical splitter 34, 36 system relay 42, 44 photoelectric converter 46, 48 decision circuit 50, 52 abnormality detection circuit 54, 56 logic gate 58, 68 abnormality location determination circuit 60, 70 AND gate 62, 64, 66, 76, 78, 80 abnormality alarm output circuit 72 74 logic gate

Claims (8)

[Claims] 1. An electro-optical conversion sensor that converts an electric signal into an optical signal in response to an electric signal to be measured, an optical splitter that splits an output of the electro-optical conversion sensor into a plurality of optical signal transmission systems, and an optical splitter. And a plurality of protection control information generators that respectively take in the optical signals from the respective optical signal transmission systems and generate protection control information on the protection target based on the respective optical signals. 2. A protection control information generator, comprising: a photoelectric converter for converting an optical signal into an electric signal; and determining whether or not an abnormality has occurred in an object to be protected based on an output of the photoelectric converter. A determination circuit that outputs information, an abnormality detection circuit that compares an output of the photoelectric converter with a set value to detect an abnormality of the optical signal transmission system, and outputs an abnormality determination output of the determination circuit by detecting an abnormality of the abnormality detection circuit. 2. The protection control system according to claim 1, further comprising an abnormality determination output prohibition circuit that forcibly prohibits the output. 3. An optical signal connecting an electro-optical conversion sensor and a protection control information generator based on an output of an abnormality detection circuit of one protection control information generator and an output of an abnormality detection circuit of the other protection control information generator. 3. The protection control system according to claim 2, further comprising an abnormal part determination circuit that determines an abnormal part of a part related to the transmission system. 4. The protection circuit according to claim 1, wherein when the abnormality detection is output from only the abnormality detection circuit of one of the protection control information generators, the input side of the photoelectric converter of one of the protection control information generators and the photoelectric conversion unit. Output a determination result indicating that an abnormality has occurred in a portion between the output side of the optical branching device connected to the device and an abnormality detection output only from the abnormality detection circuit of the other protection control information generator A determination result indicating that an abnormality has occurred in a portion between the input side of the photoelectric converter of the other protection control information generator and the output side of the optical splitter connected to the photoelectric converter is output, and both of them are output. When an abnormality detection is output from the abnormality detection circuit of the protection control information generator, an abnormality is detected in a portion between the optical splitter connected to both the protection control information generators and the electro-optical conversion sensor connected to the optical splitter. Outputs the judgment result indicating that The protection control system according to claim 3, wherein the protection control system comprises: 5. A plurality of current-to-light conversion sensors for converting a current signal into an optical signal in response to a current signal among electrical signals to be measured, and a voltage signal in response to a voltage signal among electrical signals relating to a protection target. A plurality of voltage light-to-light conversion sensors, a plurality of current light branching devices for branching the output of each current light-to-light conversion sensor to a plurality of light signal transmission systems, and a plurality of voltage light-to-light conversion sensors. Multiple voltage optical splitters for branching the output to multiple optical signal transmission systems, and optical signal transmission from each optical signal transmission system of each current optical splitter. Protection control for protection target based on each optical signal. A plurality of protection control information generators for generating information, and a plurality of protection control information generators for respectively taking in optical signals from each optical signal transmission system of each voltage optical splitter and generating protection control information on a protection target based on each optical signal. Voltage protection And a protection control information generator. 6. A protection control information generator for current and voltage, which determines from a photoelectric converter for converting an optical signal into an electric signal and whether an abnormality has occurred in a protection target from an output of the photoelectric converter. A determination circuit that outputs the determination result as protection control information, an abnormality detection circuit that compares the output of the photoelectric converter with a set value to detect an abnormality in the optical signal transmission system, and a determination circuit that detects an abnormality in the abnormality detection circuit 6. The protection control system according to claim 5, further comprising an abnormality determination output prohibiting circuit for forcibly prohibiting the output of the abnormality determination. 7. An electro-optical conversion sensor and current protection control information generation based on an output of an abnormality detection circuit of one current protection control information generator and an output of an abnormality detection circuit of the other current protection control information generator. An abnormal location determination circuit for current which determines an abnormal location of a portion relating to an optical signal transmission system connecting the optical device, an output of an abnormality detection circuit of one voltage protection control information generator, and an output of an abnormality detection circuit of the other voltage protection control information generator. 7. An abnormal part for voltage judging circuit for judging an abnormal part in a part relating to an optical signal transmission system connecting an electro-optical conversion sensor and a protection control information generator for voltage based on an output of the abnormality detecting circuit. Protection control system. 8. The photoelectric converter of one of the protection control information generators when the abnormality detection circuit for the current and the voltage respectively outputs abnormality detection only from the abnormality detection circuit of one of the protection control information generators. A determination result indicating that an abnormality has occurred in the portion between the input side of the optical converter and the output side of the optical splitter connected to this photoelectric converter is output, and only from the abnormality detection circuit of the other protection control information generator When an abnormality detection is output, it is determined that an abnormality has occurred in a portion between the input side of the photoelectric converter of the other protection control information generator and the output side of the optical splitter connected to the photoelectric converter. The result is output, and when an abnormality detection is output from the abnormality detection circuit of both protection control information generators, the optical branching device connected to both protection control information generators and the electro-optical conversion sensor connected to the optical branching device An abnormality occurred in the area between 8. The protection control system according to claim 7, wherein a determination result indicating the fact is output.