CN115376304A - Transmission device and transmission method for protection signaling of power system - Google Patents
Transmission device and transmission method for protection signaling of power system Download PDFInfo
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- CN115376304A CN115376304A CN202110558974.1A CN202110558974A CN115376304A CN 115376304 A CN115376304 A CN 115376304A CN 202110558974 A CN202110558974 A CN 202110558974A CN 115376304 A CN115376304 A CN 115376304A
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- 230000005540 biological transmission Effects 0.000 title claims abstract description 324
- 230000011664 signaling Effects 0.000 title claims abstract description 318
- 238000000034 method Methods 0.000 title claims abstract description 36
- 238000004891 communication Methods 0.000 claims description 11
- 230000003287 optical effect Effects 0.000 claims description 10
- 238000012544 monitoring process Methods 0.000 claims description 6
- 239000013307 optical fiber Substances 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 238000007781 pre-processing Methods 0.000 claims description 3
- 238000005538 encapsulation Methods 0.000 claims description 2
- 238000012546 transfer Methods 0.000 claims 13
- 238000010586 diagram Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 3
- 230000001012 protector Effects 0.000 description 3
- 230000003068 static effect Effects 0.000 description 2
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- G—PHYSICS
- G08—SIGNALLING
- G08C—TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS
- G08C23/00—Non-electrical signal transmission systems, e.g. optical systems
- G08C23/06—Non-electrical signal transmission systems, e.g. optical systems through light guides, e.g. optical fibres
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00016—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00016—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus
- H02J13/00017—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus using optical fiber
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00019—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using optical means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00028—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment involving the use of Internet protocols
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
- H02J13/00036—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers
- H02J13/0004—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving switches, relays or circuit breakers involved in a protection system
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Emergency Protection Circuit Devices (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention provides a transmission device and a method for protection signaling of a power system, wherein the transmission device comprises: the power system includes a plurality of power stations connected via a wide area network, each power station having a transmission device, the transmission device including: a first transmission unit for transmitting protection signaling with a first power station; a second transmission unit for transmitting the protection signaling with a second power station; and the processor is used for receiving the protection signaling sent by the first transmission unit, determining to issue the protection signaling or forwarding the protection signaling to the second transmission unit according to the protection signaling, receiving the protection signaling sent by the second transmission unit, and determining to issue the protection signaling or forward the protection signaling to the first transmission unit according to the protection signaling. The invention can realize single-point to multi-point signaling transmission.
Description
Technical Field
The present invention relates to the field of power systems, and in particular, to a transmission apparatus and a transmission method for protection signaling of a power system.
Background
A relay protector is one of important devices in an electric power system, and is used for detecting a fault or an abnormal condition occurring in the electric power system, thereby sending a protection signaling to directly isolate and remove a fault portion. The transmission device of the protection signaling is used as interface equipment connected with the relay protector and is responsible for transmitting the protection signaling from the relay protector to a remote power station safely and timely so as to realize wide area network protection of the high-voltage transmission line.
As shown in fig. 1, in the prior art, three power stations, namely, a power station 10, a power station 11, and a power station 12, are assumed. Each power station comprises transmission means of protection signalling for the transmission of protection signalling with the same power station. In fig. 1, each power station is shown to comprise two transmission devices of protection signaling, respectively a transmission device 101 of protection signaling, a transmission device 102 of protection signaling, a transmission device 103 of protection signaling, a transmission device 104 of protection signaling, a transmission device 105 of protection signaling, and a transmission device 106 of protection signaling. In order to enable the protection signaling to be transmitted over a long distance between two electric power stations, the two electric power stations capable of communication are transmitted through a Wide Area Network (WAN). In this way, each transmission device for protection signaling can only transmit protection signaling with the same transmission device for protection signaling of one power station, that is, transmit signaling point to point. That is, the transmission apparatus 101 of the protection signaling in fig. 1 can communicate only with the transmission apparatus 103 of the protection signaling. If the power station needs to transmit the protection signaling with a second power station, only one transmission device for the protection signaling can be added, for example, the transmission device 102 for the protection signaling in the power station 10 is added to communicate with the transmission device 105 for the protection signaling in the power station 12, and the transmission device 104 for the protection signaling in the power station 11 is added to communicate with the transmission device 106 for the protection signaling in the power station 12. Thus, the cost of the power system is greatly increased.
Disclosure of Invention
In view of the above, the present invention provides a transmission apparatus for protection signaling of an electric power system, the electric power system including a plurality of electric power stations, each of the electric power stations being connected to each other via a wide area network, each of the electric power stations having a transmission apparatus, the transmission apparatus including:
a first transmission unit for transmitting protection signaling with a first power station;
a second transmission unit for transmitting the protection signaling with a second power station;
and the processor is used for receiving the protection signaling sent by the first transmission unit, determining to issue the protection signaling or forwarding the protection signaling to the second transmission unit according to the protection signaling, receiving the protection signaling sent by the second transmission unit, and determining to issue the protection signaling or forward the protection signaling to the first transmission unit according to the protection signaling.
The transmission device for the protection signaling can respectively transmit data with two power stations through two transmission units, and for the same transmission unit, the point-to-point transmission is still realized, and the independence and the safety of the transmission of the protection signaling are still ensured. In addition, the normal work of another transmission unit is not influenced by the fault of one transmission unit, and the timeliness and the reliability of signaling transmission are guaranteed to the maximum extent on the basis that single-point to multipoint transmission can be realized.
According to the transmission apparatus as described above, optionally, the transmission apparatus further includes:
and the processor sends the protection instruction to a relay protection device of the power station where the processor is located through the interface cards.
According to the transmission apparatus as described above, optionally, the first transmission unit directly transmits the protection signaling with the first power station through a wide area network;
the second transmission unit directly transmits protection signaling with the second power station through the wide area network.
According to the transmission apparatus as described above, optionally, if the connection port of the wide area network is a TDM port, the first transmission unit and the second transmission unit both include: an LID module which transmits protection signaling through a TDM port;
if the connection port of the wide area network is an optical fiber port, the first transmission unit and the second transmission unit both include: the FOM module is used for carrying out optical signal modulation processing or optical signal encapsulation processing on the protection signaling, and the LID module is used for carrying out preprocessing on the protection signaling.
According to the transmission apparatus as described above, optionally, the first transmission unit transmits the protection signaling with the first power station through a multiplexer, and the second transmission unit transmits the protection signaling with the second power station through the multiplexer.
According to the transmission apparatus as described above, optionally, the first transmission unit directly communicates with the first power station through the FOM module, and the second transmission unit directly communicates with the second power station through the FOM module.
The transmission apparatus as described above optionally further includes:
and the alarm unit is used for sending monitoring information under the condition that the transmission device does not transmit the protection signaling so as to monitor the communication condition of the wide area network and output an alarm signal.
According to the transmission apparatus as described above, optionally, the message structure transmitted by the TDM port is synchronization information, type information, address information, data information, and check information in sequence.
According to the transmission apparatus as described above, optionally, the TDM port of the LID module of the first transmission unit and the TDM port of the LID module of the second transmission unit have different transmission protocols.
According to the transmission apparatus as described above, optionally, the first transmission unit and the second transmission unit transmit protection signaling with a multiplexer through an E1 channel, the multiplexer is configured to transmit the protection signaling with the first power station and the second power station, the first transmission unit has an E1 port, and the second transmission unit has an E1 port.
According to the transmission apparatus as described above, optionally, in a case where the first transmission unit and the second transmission unit each include one LID module, one of the first transmission unit and the second transmission unit serves as a main transmission unit, and the other serves as a backup transmission unit, and the backup transmission unit can copy the protection signaling transmitted by the main transmission unit.
According to the transmission apparatus as described above, optionally, the E1 channel includes a frame header and N groups of time slots, where each group of time slots corresponds to a group of transmission signaling, and N is a positive integer greater than or equal to 4.
According to the transmission device, optionally, the protection signaling received by the transmission device is a plurality of consecutive protection signaling, and information of each protection signaling is the same, and the first transmission unit or the second transmission unit determines whether the number of the same consecutive protection signaling is greater than or equal to a preset threshold, and if the determination result is yes, sends the protection signaling to the processor.
The invention also provides an electric power station for an electric power system, comprising a transmission device for protection signaling of the electric power system as described in any one of the above.
The invention further provides an electric power system comprising a plurality of electric power stations, each electric power station being connected via a wide area network, each electric power station having a transmission device according to any one of the above.
The present invention further provides a transmission method of protection signaling for an electric power system, the electric power system including a plurality of electric power stations, each electric power station being connected to each other via a wide area network, each electric power station having a transmission device of digital protection signaling, the transmission method including:
receiving protection signaling from a first power station;
and determining that the destination of the protection signaling is a second electric power station according to the information of the protection signaling.
The protection signaling is forwarded to a second power station.
According to the transmission method described above, optionally, the method further includes:
and sending a monitoring message through the corresponding wide area network under the condition that the wide area network does not transmit the protection signaling so as to monitor the communication condition of the wide area network.
According to the transmission method described above, optionally, the message structure of the protection signaling is synchronization information, type information, address information, data information, and check information in sequence.
According to the transmission method as described above, optionally, the received protection signaling is different from a transmission protocol or a transmission interface used when forwarding the protection signaling.
According to the transmission method as described above, optionally, after receiving the protection signaling from the first power station and before determining that the protection signaling is destined for the second power station according to the information of the protection signaling, the method further includes:
judging whether the number of the same continuously received protection signaling reaches a preset threshold value or not;
and if the judgment result is yes, determining that the destination of the protection signaling is a second electric power station according to the information of the protection signaling.
According to the transmission method as described above, optionally, the receiving of the protection signaling from one first power station includes: the protection signaling of a first power station sent by a multiplexer is received through an E1 channel, wherein the E1 channel comprises a frame header and N groups of time slots, each group of time slots corresponds to a group of transmission signaling, and N is a positive integer greater than or equal to 4.
According to the transmission method as described above, optionally, after receiving the protection signaling from one first power station, the method further includes:
copying the protection signaling in real time;
the protection signaling and the copied protection signaling are respectively sent through two ports.
Drawings
The foregoing and other features and advantages of the invention will become more apparent to those skilled in the art to which the invention relates upon consideration of the following detailed description of a preferred embodiment of the invention with reference to the accompanying drawings, in which:
fig. 1 is a schematic diagram of a power system including a transmission device for protection signaling of the prior art.
Fig. 2A is a schematic structural diagram of a transmission apparatus for protection signaling of an electric power system according to an embodiment of the present invention.
Fig. 2B and 2C are schematic structural diagrams of a transmission apparatus for protection signaling of a power system according to the present invention directly transmitting protection signaling with other power stations.
Fig. 2D is a schematic structural diagram of the transmission device for protection signaling of the power system according to the present invention, which transmits the protection signaling with other power stations through the multiplexer.
Fig. 2E is a schematic structural diagram of the transmission apparatus for protection signaling of an electric power system simultaneously transmitting 4 sets of protection signaling according to the present invention.
Fig. 2F is a schematic structural diagram of a transmission device backup protection signaling for protection signaling of a power system according to the present invention.
Fig. 3 is a flowchart illustrating a transmission method of protection signaling for an electric power system according to an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by referring to the following examples.
The power system comprises a plurality of power stations, and the power stations can be connected through a wide area network to transmit protection signaling. In the present invention, one power station has 1 transmission device for protection signaling, and the transmission device can transmit protection signaling in different directions, and the specific structure of the transmission device is shown in fig. 2A. As shown in fig. 2B, the power station 11 has 1 transmission device 111 therein, the power station 12 has one transmission device 121 therein, and the power station 10 has one transmission device 20 therein. There are three power stations, the power station 11 and the power station 10 can transmit protection signaling to each other, and the power station 12 and the power station 10 can also transmit protection signaling to each other, as shown in fig. 2B, the power station 10 can transmit protection signaling in both directions D1 and D2. Further, as shown in fig. 2C, the transmission of the protection signaling between the electric power station 11 and the electric power station 12 may be forwarded by the electric power station 10, and as shown by an arrow in fig. 2C, for the electric power station 11, it may transmit the protection signaling between the electric power station 10 and the D3 direction, or may transmit the protection signaling between the electric power station 12 and the D4 direction. Therefore, the transmission device can realize the transmission mode of the single-point to multi-point protection signaling of the electric power station.
The invention provides a transmission device for protection signaling of an electric power system, which can realize single-point to multi-point signaling transmission, namely the transmission device can transmit the protection signaling in different transmission directions.
Fig. 2A is a schematic structural diagram of a transmission apparatus for protection signaling of a power system according to the present invention. The transmission apparatus 20 for protection signaling of a power system includes a first transmission unit 201, a second transmission unit 202, and a processor 203. The first transmission unit 201 is configured to transmit a protection signaling with a first power station 11, the second transmission unit 202 is configured to transmit a protection signaling with a second power station 12, and the processor 203 is configured to receive the protection signaling sent by the first transmission unit 201, determine to issue the protection signaling or forward the protection signaling to the second transmission unit 202 according to the protection signaling, and receive the protection signaling sent by the second transmission unit 202, and determine to issue the protection signaling or forward the protection signaling to the first transmission unit 201 according to the protection signaling. The power station where the transmission apparatus is located is a power station 10.
As an exemplary illustration, as shown in fig. 2B and fig. 2C, a wide area network is connected between the first transmission unit 201 and the first power station 11, and through the wide area network, the first transmission unit 201 can directly transmit the protection signaling with the first power station 11, that is, the physical connection can ensure the transmission of the protection signaling between the first transmission unit 201 and the first power station 11. Similarly, a wide area network is connected between the second transmission unit 202 and the second power station 12, and the second transmission unit 202 can directly transmit the protection signaling to the second power station 12 through the wide area network. More specifically, the transmission device 20 is connected to the transmission device 111 in the first power station 11 and the transmission device 121 in the second power station 12. As another exemplary illustration, as shown in fig. 2D, the first transmission unit 201 and the second transmission unit 202 may be connected to a multiplexer 21 (MUX), and the multiplexer 21 may be physically connected to other power stations and may transmit the protection signaling, that is, the first transmission unit 201 transmits the protection signaling with the first power station through the multiplexer 21, and the second transmission unit 202 transmits the protection signaling with the second power station through the multiplexer 21. Since many power stations in the prior art have the multiplexer 21, and the multiplexer 21 is mainly used for multiplexing the low-rate data and converting the multiplexed low-rate data into higher-rate data for transmission, the transmission device of the embodiment can also be matched with the multiplexer 21, so that the transmission device can be well compatible with a hardware structure in the prior art.
The processor 203 (Processing Unit) is configured to receive the protection signaling sent by the first transmission Unit 201, determine to issue the protection signaling or forward the protection signaling to the second transmission Unit 202 according to the group of protection signaling, and receive the protection signaling sent by the second transmission Unit 202, and determine to issue the protection signaling or forward the protection signaling to the first transmission Unit 201 according to the group of protection signaling. The information of the protection signaling includes an address of a sending end of the protection signaling, that is, a source address, since each source address is matched with a destination address in advance, the processor 203 determines whether the source addresses are matched according to the preset information, and if the source addresses are matched, the processor 203 further determines whether to issue or forward the protection signaling according to a DATA segment in the protection command, that is, the processor 203 sends the protection signaling downwards or the processor 203 forwards the protection signaling to the second transmission unit 202, so that the protection signaling can be sent to the second power station 12 through the second transmission unit 202 to implement communication between the first power station 11 and the second power station 12, that is, as shown in a "T" type communication architecture shown by a dotted line in fig. 2B, similarly, the protection signaling sent by the second power station 12 can also be forwarded to the first power station 11 through a transmission device of the protection signaling. The processor may be at least one of the following devices: microprocessor (Micro Processor), digital Signal Processor (DSP), programmable logic array (FPGA).
The transmission device for the protection signaling can respectively transmit data with two power stations through two transmission units, and for the same transmission unit, the point-to-point transmission is still realized, so that the independence and the safety of the transmission of the protection signaling are still ensured. In addition, the normal operation of another transmission unit is not influenced by the fault of one transmission unit, and the timeliness and reliability of the protection signaling transmission are ensured to the maximum extent on the basis of realizing single-point to multipoint transmission.
In this embodiment, if the wan is a Digital Line, the first transmission unit 201 and the second transmission unit 202 may respectively include an LID (Line Interface Digital, digital Interface module) 2011, and the LID module 2011 transmits the protection signaling through a TDM (Time-Division Multiplexing) port. The LID module 2011 can preprocess the protection signaling to form a message structure as shown in table 1, implement different digital transmission coding modes (AMI code and HDB3 code), match different TDM ports, calculate a transmission error rate, monitor a line transmission state in real time, quickly switch to a backup line when a fault occurs, reliably receive the protection signaling, and the like.
If the wide area network between two power stations is an optical Fiber line, the first transmission unit 201 includes an LID module 2011 and an FOM (Fiber-optical Modem) module 2012, and the second transmission unit 202 may also include an LID module 2011 and an FOM module 2012. Specifically, for example, the FOM module 2012 of the first transmission unit 201 receives the protection signaling, then performs optical signal modulation processing, and sends the protection signaling to the LID module 2011 of the first transmission unit 201 to perform protection signaling preprocessing, the LID module 2011 of the first transmission unit 201 sends the protection signaling to the processor 203, if the processor 203 identifies that the protection signaling should be forwarded to the second power station 12 according to the protection signaling, the processor sends the protection signaling to the LID module 2011 of the second transmission unit 202, the LID module 2011 preprocesses the protection signaling, the FOM module 2012 encapsulates the preprocessed signaling, and the FOM module 2012 of the second transmission unit 202 sends the protection signaling to the second power station 12 through an optical port (not shown in the figure) of the FOM module 2012. Wherein a port of the FOM module 2012 can be directly connected to a second power station via an optical fiber.
Alternatively, the protocols employed by the TDM ports of the two transmission units may be the same or different. As an exemplary illustration, if the adopted protocols are the same, the structures of the two transmission units are the same. As an illustrative example, if the protocols used are different, for example, one TDM port uses an x.21 port or a g.703.1 port of 64kbps and the other TDM port uses a g.703.6 port or a fiber port of 2Mbps, so that the different protocols are adapted to different required transmission lines. For example, if the wide area network corresponding to one transmission unit is an optical fiber line and the wide area network corresponding to another transmission unit is a digital line, the transmission unit corresponding to the optical fiber line may have both the LID module 2011 and the FOM module 2012, and the transmission unit corresponding to the digital line may have one LID module 2011, which may be specifically selected according to actual needs, that is, according to actual physical connection, related hardware configuration and software configuration are implemented.
The message structure transmitted by the TDM port is synchronization information (SYNC), TYPE information (TYPE), address information (ADR), DATA information (DATA), and check information (CRC) in sequence, which is specifically shown in table 1. The SYNC indicates a message synchronization signal (Telegram alignment signal), the TYPE indicates a TYPE of the message, the address information includes a source address of the message, and the verification information is used for consistency verification. After receiving the protection signaling, the transmission unit performs consistency check, the consistency check detects whether a check value included in the check information is correct, if so, determines whether the address information matches with a preset address of a communicable power station, and if so, the consistency check passes, decodes the protection signaling, and sends the protection signaling downwards or forwards the protection signaling. How to decode belongs to the prior art, and is not described herein again. If the consistency check does not pass, the protection signaling is discarded. The issue and forward flow is described as an exemplary illustration: a) After receiving the protection signaling, the transmission device 20 determines the starting position of the message of the protection signaling according to the SYNC, if the message fails, the message is discarded, otherwise, the process enters b); b) Determining whether the signaling message is a protection signaling message according to TYPE, if the TYPE is wrong, discarding the message, otherwise entering c); c) Checking whether the CRC is correct, if the CRC is wrong, discarding the message, and if not, entering d); d) Checking whether the ADR is matched with a preset destination address, if not, discarding the message, otherwise, entering e); e) DATA is checked, each DATA having a preconfigured static route, and the processor 203 determines whether to issue the protection signaling or forward the protection signaling according to the static route.
The time for transmitting this protection signaling is very critical and has been specified in the standard IEC 60834-1. In order to ensure the timely transmission of the protection signaling, the transmission speed of the TDM port may be 2Mbps, which can cause very small delay due to forwarding, for example, less than 0.1ms.
TABLE 1
| SYNC | TYPE | ADR | DATA | CRC |
As shown in fig. 2A, transmission apparatus 20 further includes a set of interface cards 204, and processor 203 sends protection instructions down through interface cards 204. The downward transmission of the protection command here means transmission of the protection command to the relay protection device of the same power station. In fig. 2, there are 4 interface cards 204, and the number of interface cards 204 may be adjusted according to actual needs. Each interface card 204 may transmit 4 sets of protection signaling simultaneously.
Optionally, the transmission device 20 further comprises an alarm unit 205, wherein the alarm unit 205 is configured to monitor an operational status of the transmission device. Since the transmission device itself is a transceiver, it is known whether or not it transmits the protection signaling, and in the case where the protection signaling is not transmitted, the transmission device continuously transmits monitoring information to monitor the communication line condition of the wide area network. Optionally, the alarm unit 205 may also implement an alarm by self-detection, for example, when the transmission fails or the power is insufficient, the alarm may be performed.
Optionally, the transmission device 20 further comprises a power module 206, and the power module 206 is used for providing power.
In the presence of the multiplexer 21, both the first transmission unit 201 and the second transmission unit 202 may be connected to one multiplexer 21 through the E1 channel, and the protection signaling is transmitted through the multiplexer 21, and the multiplexer 21 is used to transmit the protection signaling with the first power station 11 and the second power station 12. Each transmission unit has one E1 port, and two E1 ports enable transmission of protection signaling in two directions. In practical applications, each E1 port can support simultaneous transmission of 2 signaling groups, and each signaling group may include 4 or 8 signaling. Such a technique is called a channelized E1 technique (CE 1 technique). In this way, for a transmission apparatus including two transmission units having 4E 1 ports, transmission of protection signaling in 4 directions can be realized in the presence of the multiplexer 21. As shown in fig. 2E, the transmitting device can simultaneously transmit the protection signaling channel E1 in the four directions a, B, C and D, and uses PCM (Pulse Code Modulation) for decoding or encoding.
In the frame structure of the E1 channel, the transmission speed is 2.048Mbps,8 bits form a time slot (Ts), and 32 time slots form a frame (F). The 32 timeslots can be divided into a frame header and a plurality of groups of timeslots, for example, N groups of timeslots, according to actual needs, each group of timeslots corresponds to a group of transmission signaling, where N is a positive integer greater than or equal to 4. As an exemplary illustration, in the case of N =4, slots 1-5 are allocated to the first set of transmission signaling, slots 6-10 are allocated to the second set of transmission signaling, and slots 11-31 are reserved for subsequent extended functionality, e.g., one set every 5 slots. Correspondingly, in the frame structure of the E1 channel corresponding to another transmission unit, the time slots 1-5 are allocated to the third group for signaling transmission, the time slots 6-10 are allocated to the fourth group for signaling transmission, and the time slots 11-31 are reserved for subsequent extended functions. Specifically, as shown in table 2 and table 3, the frame structure of the E1 channel corresponding to the first transmission unit 201 and the frame structure of the E1 channel corresponding to the second transmission unit 202 are respectively shown. Where FAS (Frame Alignment Signal) indicates the Frame header, which is located at time slot 0. The structure of each protection signaling may be as shown in table 1.
TABLE 2
TABLE 3
After receiving the protection signaling through the E1 channel, the transmission device analyzes the protection signaling, for example, performs a consistency check after removing the frame header, where the consistency check mode is consistent with the foregoing one, and is not described herein again.
As an exemplary illustration, in a case where a transmission unit needs to transmit protection signaling through an E1 channel and in a case where the first transmission unit and the second transmission unit each include one LID module, one LID module of the two transmission units may serve as a backup transmission unit and the other LID module may serve as a main transmission unit. For example, the first transmission unit 201 is a unit that mainly transmits protection signaling, and has 1E 1 port. The second transmission unit 202, as a backup transmission unit, also has 1E 1 port and can duplicate the protection signaling transmitted by the first transmission unit 201, so that these 2E 1 ports send the same protection signaling at the same time. As an exemplary illustration, as a transmission device on the transmitting side, the received protection signaling is duplicated, and the two same protection signaling are respectively transmitted through 2E 1 ports. And as the transmission device at the receiving side, after the failure of the main transmission unit is identified, the transmission device is automatically switched to the backup transmission unit to receive the protection signaling so as to avoid the loss of the protection signaling. Therefore, when the transmission device receiving the protection signaling identifies that the port or the transmission line in the main transmission unit of the transmission device sending the protection signaling has a fault, the transmission device automatically switches to the backup transmission unit to receive the protection signaling, and can ensure the normal transmission and reception of the protection signaling. Meanwhile, each E1 channel can respectively transmit two groups of different protection signaling, namely the transmission device can simultaneously support one-to-many transmission and 1+1 line backup transmission. As shown in fig. 2F, the transmission apparatus is capable of simultaneously transmitting the protection signaling in both directions a and B and backing up the protection signaling in both directions a and B, and the dotted line represents the backup line.
Optionally, the protection signaling received by the transmission device is multiple continuous protection signaling, and information of each protection signaling is the same, and the first transmission unit 201 or the second transmission unit 202 determines whether the number of the same continuous protection signaling received reaches a preset threshold, and if the determination result is yes, sends the number of the same continuous protection signaling to the processor 203. To ensure that the protection signaling is not lost, multiple identical protection signaling are typically sent consecutively. After receiving the same protection signaling, the first transmission unit 201 or the second transmission unit 202 determines whether the protection signaling should be transmitted according to the received number, and when the number of the protection signaling reaches a preset threshold, it indicates that the protection signaling can be safely received.
The invention also provides a transmission method of the protection signaling for the power system, wherein the power system comprises a plurality of power stations, and each power station is connected with each other through the wide area network. Each power station has a transmission means of digital protection signalling.
As shown in fig. 3, the transmission method includes:
Specifically, the protection signaling sent by the first power station may be directly received through a physically connected wide area network, or may be received through a multiplexer.
If the protection signaling is an optical signal, the optical signal is processed after the protection signaling in the form of the optical signal is received, and how to process the optical signal belongs to the prior art, which is not described herein again.
The protection signaling has a source address, whether a preset destination address is matched is determined according to the source address, and whether the protection signaling needs to be sent downwards or the protection signaling needs to be forwarded to the second power station is determined according to the protection signaling.
And if the matched destination address is the second electric power station, forwarding the protection signaling to the second electric power station.
Optionally, in a case where the protection signaling is not transmitted, the communication condition of the wide area network is monitored by sending a monitoring message to the corresponding wide area network.
Optionally, the message structure of the protection signaling is synchronization information, type information, address information, data information, and check information in sequence.
Optionally, the received protection signaling is different from a transmission protocol or a transmission interface used when forwarding the protection signaling. In this way, different physical connections can be matched.
Optionally, the receiving of the protection signaling from the first power station comprises: the protection signaling of a first electric power station sent by a multiplexer is received through an E1 channel, and a time slot of the E1 channel comprises a frame header and N groups of time slots, wherein each group of time slots corresponds to one group of transmission signaling, and N is a positive integer greater than or equal to 4.
Optionally, after receiving the protection signaling from the first power station, the method further includes:
copying the protection signaling in real time;
the protection signaling and the copied protection signaling are respectively sent through two ports. As an exemplary illustration, as a transmission device on the transmitting side, the received protection signaling is duplicated, and the two same protection signaling are respectively transmitted through 2E 1 ports. And the transmission device serving as the receiving side automatically switches to the backup transmission unit to receive the protection signaling after recognizing that the main transmission unit of the transmission device has a fault so as to avoid the loss of the protection signaling.
Optionally, after receiving the protection signaling from the first power station and before determining, according to the information of the protection signaling, that the protection signaling is destined for the second power station, the method further includes:
judging whether the number of the same continuously received protection signaling reaches a preset threshold value or not;
and if so, performing the operation of determining that the destination of the protection signaling is a second electric power station according to the information of the protection signaling.
The specific process of the transmission method is consistent with the foregoing embodiments, and is not described herein again.
By the transmission method for the protection signaling of the power system, the same power station can realize the transmission of the protection signaling from one point to multiple points, so that the cost is saved.
The invention also provides an electric power station for an electric power system, which comprises the transmission device for the protection signaling of the electric power system.
The invention also provides a power system which comprises a plurality of power stations, each power station is provided with a transmission device, and the transmission of the group of protection signaling from single point to multi-point is realized through the transmission device, and the transmission device is the transmission device.
The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (22)
1. Transmission apparatus for protection signalling for an electric power system comprising a plurality of electric power stations each connected via a wide area network, wherein each of said electric power stations has a transmission apparatus comprising:
a first transmission unit for transmitting protection signaling with a first power station;
a second transmission unit for transmitting the protection signaling with a second electric power station;
and the processor is used for receiving the protection signaling sent by the first transmission unit, determining to issue the protection signaling or forwarding the protection signaling to the second transmission unit according to the protection signaling, receiving the protection signaling sent by the second transmission unit, and determining to issue the protection signaling or forward the protection signaling to the first transmission unit according to the protection signaling.
2. The transmission apparatus according to claim 1, characterized in that the transmission apparatus further comprises:
and the processor sends the protection instruction to a relay protection device of the power station where the processor is located through the interface cards.
3. The transmission apparatus according to claim 1, wherein the first transmission unit transmits the protection signaling directly with the first electric station via a wide area network;
the second transmission unit directly transmits the protection signaling with the second power station through the wide area network.
4. The transmission apparatus according to claim 1, wherein if the connection port of the wide area network is a TDM port, the first transmission unit and the second transmission unit each include: an LID module that transmits protection signaling through a TDM port;
if the connection port of the wide area network is an optical fiber port, the first transmission unit and the second transmission unit both include: the FOM module is used for carrying out optical signal modulation processing or optical signal encapsulation processing on the protection signaling, and the LID module is used for carrying out preprocessing on the protection signaling.
5. The transmission apparatus according to claim 4, wherein the first transmission unit transmits the protection signaling with the first power station through a multiplexer, and the second transmission unit transmits the protection signaling with the second power station through the multiplexer.
6. The transmission apparatus of claim 4, wherein the first transmission unit is in direct communication with the first power station via a FOM module, and wherein the second transmission unit is in direct communication with the second power station via a FOM module.
7. The transmission apparatus according to claim 1, further comprising:
and the alarm unit is used for sending monitoring information under the condition that the transmission device does not transmit the protection signaling so as to monitor the communication condition of the wide area network and output an alarm signal.
8. The transmission apparatus according to claim 4, wherein the message structure transmitted by the TDM port is, in order, synchronization information, type information, address information, data information, and check information.
9. The transfer apparatus of claim 4, wherein the TDM port of the LID module of the first transfer unit is of a different transfer protocol than the TDM port of the LID module of the second transfer unit.
10. The transmission apparatus according to claim 1, wherein the first transmission unit and the second transmission unit transmit the protection signaling with a multiplexer through an E1 channel, the multiplexer is configured to transmit the protection signaling with the first power station and the second power station, the first transmission unit has an E1 port, and the second transmission unit has an E1 port.
11. The transfer device of claim 10, wherein in the case where the first transfer unit and the second transfer unit each include one LID module, one of the first transfer unit and the second transfer unit serves as a primary transfer unit and the other serves as a backup transfer unit, and the backup transfer unit is capable of copying protection signaling transferred by the primary transfer unit.
12. The transmission apparatus as claimed in claim 8, wherein the E1 channel includes a frame header and N groups of slots, wherein each group of slots corresponds to a group of transmission signaling, and N is a positive integer greater than or equal to 4.
13. The transmission apparatus according to any one of claims 1 to 12, wherein the protection signaling received by the transmission apparatus is multiple consecutive protection signaling, and information of each protection signaling is the same, and the first transmission unit or the second transmission unit determines whether the number of the same protection signaling received consecutively is greater than or equal to a preset threshold, and if yes, sends the protection signaling to the processor.
14. Power station for an electric power system, characterized in that it comprises a transmission device for protection signaling of an electric power system according to any of claims 1-13.
15. An electric power system comprising a plurality of electric power stations each connected via a wide area network, wherein each of the electric power stations has a transmission device according to any one of claims 1 to 12.
16. A method for transmitting protection signalling for an electric power system comprising a plurality of electric power stations each connected to each other by a wide area network, wherein each electric power station has means for transmitting digital protection signalling, said method comprising:
receiving protection signaling from a first power station;
and determining that the destination of the protection signaling is a second electric power station according to the information of the protection signaling.
The protection signaling is forwarded to a second power station.
17. The transmission method according to claim 16, further comprising:
and sending a monitoring message through the corresponding wide area network under the condition that the wide area network does not transmit the protection signaling so as to monitor the communication condition of the wide area network.
18. The transmission method according to claim 16, wherein the message structure of the protection signaling is synchronization information, type information, address information, data information, and check information in sequence.
19. The transmission method according to claim 16, wherein the received protection signaling is different from a transmission protocol or a transmission interface used when forwarding the protection signaling.
20. The method according to claim 16, further comprising, after receiving the protection signaling from the first power station and before determining that the protection signaling is destined for the second power station according to the information of the protection signaling:
judging whether the number of the same continuously received protection signaling reaches a preset threshold value or not;
and if so, performing the operation of determining that the destination of the protection signaling is a second electric power station according to the information of the protection signaling.
21. Transmission method according to any of claims 16-20, wherein receiving protection signalling from a first power station comprises: the protection signaling of a first power station sent by a multiplexer is received through an E1 channel, wherein the E1 channel comprises a frame header and N groups of time slots, each group of time slots corresponds to a group of transmission signaling, and N is a positive integer greater than or equal to 4.
22. The transmission method according to claim 21, further comprising, after receiving the protection signaling from the first power station:
copying the protection signaling in real time;
the protection signaling and the copied protection signaling are respectively sent through two ports.
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| CN202110558974.1A CN115376304A (en) | 2021-05-21 | 2021-05-21 | Transmission device and transmission method for protection signaling of power system |
| PCT/EP2022/063504 WO2022243401A1 (en) | 2021-05-21 | 2022-05-19 | Transmission apparatus and method for protection signaling of power system |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1237024A (en) * | 1998-03-05 | 1999-12-01 | 东芝株式会社 | Controlling system, protection controlling system for power system and storage medium for storing program |
| CN106411790A (en) * | 2016-09-29 | 2017-02-15 | 北京东土科技股份有限公司 | Data transmission method based on protection and control system of intelligent substation |
| CN109327809A (en) * | 2017-08-01 | 2019-02-12 | 中国电力科学研究院 | A kind of real-time retransmission method of Substation process-level information and device |
| CN111800324A (en) * | 2020-06-23 | 2020-10-20 | 广西电网有限责任公司电力科学研究院 | Intelligent substation HSR node forwarding method and device |
| KR20210008255A (en) * | 2019-07-12 | 2021-01-21 | 구스텍 주식회사 | Remote shutdown control system |
| US20210111555A1 (en) * | 2019-10-12 | 2021-04-15 | Schweitzer Engineering Laboratories, Inc. | Primary and system protection for an electric power delivery system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59162711A (en) * | 1983-03-04 | 1984-09-13 | 株式会社東芝 | Protective relaying device |
| US8553530B1 (en) * | 2009-03-06 | 2013-10-08 | Dragonwave Inc. | Operating state control in redundancy protection systems |
-
2021
- 2021-05-21 CN CN202110558974.1A patent/CN115376304A/en active Pending
-
2022
- 2022-05-19 WO PCT/EP2022/063504 patent/WO2022243401A1/en active Application Filing
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1237024A (en) * | 1998-03-05 | 1999-12-01 | 东芝株式会社 | Controlling system, protection controlling system for power system and storage medium for storing program |
| CN106411790A (en) * | 2016-09-29 | 2017-02-15 | 北京东土科技股份有限公司 | Data transmission method based on protection and control system of intelligent substation |
| CN109327809A (en) * | 2017-08-01 | 2019-02-12 | 中国电力科学研究院 | A kind of real-time retransmission method of Substation process-level information and device |
| KR20210008255A (en) * | 2019-07-12 | 2021-01-21 | 구스텍 주식회사 | Remote shutdown control system |
| US20210111555A1 (en) * | 2019-10-12 | 2021-04-15 | Schweitzer Engineering Laboratories, Inc. | Primary and system protection for an electric power delivery system |
| CN111800324A (en) * | 2020-06-23 | 2020-10-20 | 广西电网有限责任公司电力科学研究院 | Intelligent substation HSR node forwarding method and device |
Non-Patent Citations (1)
| Title |
|---|
| 陈刚: "航天测控通信系统网络技术", 30 September 2020, 国防工业出版社, pages: 30 - 35 * |
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