A digital relay protection distribution terminal device and its operation method

Abstract

This invention discloses a relay protection distribution terminal device and its operation method. The device includes a housing, a CPU board, a first terminal communication channel, and a second terminal communication channel. The CPU board is located inside the housing and is connected to a data acquisition unit installed on a circuit breaker via the first and second terminal communication channels. It independently acquires circuit breaker messages collected by the data acquisition unit. The messages are transmitted simultaneously in the first and second terminal communication channels using data block interleaving and redundant transmission technology with dual protocols. The CPU board runs a relay protection program to verify, reassemble, and identify power distribution line faults in the messages acquired through the first and second terminal communication channels, and controls tripping when a power distribution line fault occurs. This invention improves the reliability of message transmission using cables, reduces the occurrence of maloperation of the relay protection distribution terminal due to failure to receive correct messages when a power distribution line fault occurs, thereby improving the anti-interference and reliability of the digital relay protection distribution terminal.

Description

Technical Field

[0001] This invention belongs to the field of relay protection technology and relates to a digital relay protection distribution terminal device and its operation method. Background Technology

[0002] Relay protection is the first line of defense for maintaining the safe and stable operation of the power system. It is necessary to quickly and reliably isolate system faults that endanger the safety of the power grid. Currently, relay protection functions are also widely configured in the distribution terminals used in the distribution network.

[0003] With technological advancements, primary equipment in power distribution systems, including circuit breakers, voltage transformers, and current transformers, is showing a trend towards deep integration. This means that voltage and current transformers are now integrated within the terminals of the circuit breaker, rather than being externally mounted. In this case, the output power of the voltage and current transformers decreases, thus requiring a smaller signal output. Typically, the rated secondary output voltage of an externally mounted transformer is 100V, and the rated secondary output current of a current transformer is 1A. With the adoption of smaller signal output, the rated secondary output voltage of the voltage transformer is converted to 3.25V, and the secondary output of the current transformer is also converted to a smaller voltage signal, with a corresponding rated value of 1V. Because the signal amplitude of the transformer's secondary output is much smaller than that of an externally mounted transformer, and it must be transmitted through a 6-15 meter cable to the relay protection distribution terminal, interference from spatial electromagnetic fields can cause relatively large changes in the measured value, increasing the risk of relay protection malfunction.

[0004] To address the vulnerability of direct transmission of small signals from instrument transformers to interference, some manufacturers have adopted digital signal transmission solutions. This involves using a data acquisition device installed on the circuit breaker to convert the small signals from the instrument transformers into digital quantities. The sampled values ​​are then transmitted to the relay protection distribution terminal via messages, thus creating a digital relay protection distribution terminal. Because a checksum is included in the message, if interference occurs during transmission and causes errors, the checksum can identify the interference and prevent the use of erroneous data, thus mitigating the risk of malfunction due to interference in the transmission process.

[0005] Digital signal transmission schemes are already in use in substations. Local sampling units collect signals such as voltage and current, convert them into digital signals, and then transmit them to relay protection devices via fiber optic channels using standardized protocol messages. Figure 1 As shown, Figure 1In this diagram, CB represents the switch, MU is the local sampling unit (mounted on CB), RLY is the relay protection device, and FB is the transmission fiber between the local sampling unit and the relay protection device. Compared to traditional signal transmission methods, this device uses optical signals to transmit information via fiber optics. Optical signals are not affected by spatial electromagnetic fields, resulting in better stability during message transmission. However, relay protection distribution terminals are used in power distribution networks and often operate outdoors for extended periods. If fiber optic cables are used for transmission, the corresponding optical components are more susceptible to damage outdoors. Therefore, manufacturers using digital signal transmission solutions believe that replacing fiber optic cables with electrical cables—that is, using electrical cables to transmit messages via electrical signals—is more suitable, less prone to damage, and has a longer lifespan. Thus, electrical cables are used instead of fiber optic cables. Figure 2 As shown, Figure 2 In this diagram, CB is a switch, MU is a local sampling unit (MSU) mounted on CB, and FTU is a relay protection distribution terminal unit. MU and FTU are connected and communicate via two cables, RX and TX. RX is the cable used by the FTU to receive signals, and TX is the cable used by the FTU to transmit signals. While using cables to transmit digital signals can improve service life, cables transmit electrical signals, which are more susceptible to interference from electromagnetic fields and less stable than optical signals. When transmitted messages are interfered with, errors may occur. Although checksums can be used to verify and discard erroneous messages, these erroneous messages may actually be those sent during a distribution network fault. Especially during a distribution network fault, the electromagnetic field impact is most severe due to electromagnetic transients. Discarding erroneous messages caused by interference can lead to the relay protection distribution terminal unit failing to receive fault signals due to message errors, thus preventing fault diagnosis and action to clear the fault, resulting in relay protection failure. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a digital relay protection terminal device and its operation method, avoiding the interference that can easily cause the relay protection distribution terminal to fail to operate when using cables to transmit digital signals.

[0007] The present invention adopts the following technical solution.

[0008] The first aspect of this invention provides a relay protection distribution terminal device, comprising a housing, a CPU board, a first terminal communication channel, a second terminal communication channel, and a data acquisition unit, wherein the data acquisition unit is mounted on a circuit breaker, characterized in that:

[0009] The CPU board is placed inside the casing and is connected to the acquisition unit installed on the switch circuit breaker through the first terminal communication channel and the second terminal communication channel respectively, so as to independently acquire the switch circuit breaker message collected by the acquisition unit. The message adopts data block interleaving and redundant transmission technology in the first terminal communication channel and the second terminal communication channel to transmit simultaneously with dual protocols.

[0010] The CPU board runs a relay protection program to verify, reassemble, and identify power distribution line faults in the messages transmitted through the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology, and controls the tripping when a power distribution line fault occurs.

[0011] Preferably, the number of acquisition units is one, and it is provided with a first acquisition end communication channel and a second acquisition end communication channel. The first acquisition end communication channel and the second acquisition end communication channel are respectively connected to the first terminal communication channel and the second terminal communication channel to transmit messages independently.

[0012] Preferably, there are two acquisition units, namely a first acquisition unit and a second acquisition unit. The first acquisition unit is provided with a first acquisition unit communication channel, and the second acquisition unit is provided with a second acquisition unit communication channel. The first acquisition unit communication channel and the second acquisition unit communication channel are respectively connected to the first terminal communication channel and the second terminal communication channel to transmit messages independently.

[0013] Preferably, the first acquisition unit and the second acquisition unit are installed at different positions on the circuit breaker.

[0014] Preferably, the simultaneous transmission of dual protocols refers to the simultaneous transmission of messages using different protocols in the first terminal communication channel and the second terminal communication channel.

[0015] Preferably, the data block interleaving transmission technology refers to the first terminal communication channel and the second terminal communication channel dividing the message into data blocks and transmitting them in an interleaved order.

[0016] Preferably, the data block redundancy transmission technology refers to: the first terminal communication channel and / or the second terminal communication channel dividing the message into data blocks for transmission, and each data block being transmitted at least twice in each frame message.

[0017] Preferably, the first terminal communication channel and the second terminal communication channel can simultaneously employ data block interleaving and redundant transmission techniques, specifically:

[0018] The first terminal communication channel and the second terminal communication channel divide the message into data blocks for transmission, and each data block is transmitted at least twice in each frame of message, and the transmission is interleaved.

[0019] Preferably, the relay protection program verifies the messages transmitted by the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology. If one message fails to be verified while the other message passes verification, the normally verified message is parsed to identify the power distribution line fault.

[0020] If both message verifications are normal, then either message is parsed to identify power distribution line faults.

[0021] If both message verifications fail, the parts of the two messages that have passed verification are reassembled. If a correct and complete message can be obtained through reassembly, the reassembled message is used to identify the fault in the power distribution line. If both message verifications fail and a correct and complete message cannot be obtained through reassembly, the protection is blocked and a verification prompt message is issued.

[0022] Preferably, the relay protection program controls the tripping in the event of a power distribution line fault by: directly driving the tripping relay configured in this device to trip; or, transmitting the tripping signal to the acquisition unit on the switch circuit breaker via communication messages through the first terminal communication channel and the second terminal communication channel respectively, and the acquisition unit verifies and parses the message before driving its built-in relay to trip.

[0023] A second aspect of the present invention provides an operation method for the relay protection distribution terminal device, comprising:

[0024] The CPU board obtains the switch circuit breaker messages collected by the acquisition unit on the switch circuit breaker through the first terminal communication channel and the second terminal communication channel respectively, and uses data block interleaving and redundant transmission technology to transmit messages simultaneously with dual protocols.

[0025] The CPU board runs a relay protection program to verify, reassemble, and identify power distribution line faults in messages transmitted through the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology, and controls the tripping when a power distribution line fault occurs.

[0026] The beneficial effects of this invention are compared with those of the prior art:

[0027] This invention employs dual communication channels for message transmission. When one communication channel of the relay protection distribution terminal device is interfered with, resulting in a message verification error, the other uninterrupted transmission cable can still be used to obtain the correct message for relay protection program calculation, thereby increasing the probability of obtaining the correct message. Furthermore, by using different protocols for the dual communication channels, employing interleaved message content transmission, increasing the redundancy of transmitted data blocks, and combining interleaved and redundant transmission, the reliability of message transmission via cable is further improved. This reduces the occurrence of maloperation of the relay protection distribution terminal due to failure to receive the correct message when the distribution line is faulty, thereby improving the anti-interference and reliability of the digital relay protection distribution terminal. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the use of optical fiber to transmit information in the existing technology for the acquisition unit and relay protection device;

[0029] Figure 2 This is a schematic diagram of the use of cables to transmit information in existing technology for data acquisition units and relay protection distribution terminal devices;

[0030] Figure 3 This is a schematic diagram of a relay protection distribution terminal with two communication channels;

[0031] Figure 4 This is a schematic diagram of a relay protection distribution terminal connected to a dual-communication channel acquisition unit via two channels.

[0032] Figure 5 This is a schematic diagram of a relay protection power distribution terminal connected to two single communication channel acquisition units respectively through two channels;

[0033] Figure 6 This is a schematic diagram of interleaved content transmission messages in dual communication channels;

[0034] Figures 1-5 The reference numerals in the attached diagram are as follows: A - casing, B - CPU board, C - first terminal communication channel, D - second terminal communication channel, CB - circuit breaker, E - first acquisition terminal communication channel, F - second acquisition terminal communication channel, MU1 - first acquisition unit, MU2 - second acquisition unit, G - first acquisition unit communication channel, H - second acquisition unit communication channel. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0036] like Figure 3 As shown, Embodiment 1 of the present invention provides a relay protection distribution terminal device, including a housing A, a CPU board B, a first terminal communication channel C and a second terminal communication channel D for communication, and a data acquisition unit, which is installed on the circuit breaker CB.

[0037] The CPU board B is placed inside the outer casing A and is connected to the acquisition unit installed on the circuit breaker CB through the first terminal communication channel C and the second terminal communication channel D respectively, so as to independently acquire the circuit breaker CB message collected by the acquisition unit. The message adopts data block interleaving and redundant transmission technology in the first terminal communication channel C and the second terminal communication channel D to transmit simultaneously with dual protocols.

[0038] The CPU board runs a relay protection program, receiving switch and circuit breaker messages (including analog signals and digital signals) independently uploaded by the first terminal communication channel C and / or the second terminal communication channel D using data block interleaving and redundant transmission technology. It verifies and reassembles these messages, and parses them to obtain the transmitted analog quantities such as voltage and current, as well as the digital signals such as trip position, closing position, spring de-energization, and low trip / closing pressure on the switch. It uses the obtained analog and digital signals to implement the relay protection algorithm, identify power distribution line faults, and trip the circuit breaker when a fault occurs.

[0039] More preferably, such as Figure 4 As shown, the acquisition unit is an acquisition unit MU2Port installed on the circuit breaker CB. It has a first acquisition end communication channel E and a second acquisition end communication channel F. The first acquisition end communication channel E is connected to the first terminal communication channel C via the receiving cable RX1 and the transmitting cable TX1 of the first communication cable. The second acquisition end communication channel F is connected to the second terminal communication channel D via the receiving cable RX2 and the transmitting cable TX2 of the second communication cable, forming independent communication channels for transmitting signals. In specific implementation, Figure 4In the process, the acquisition unit MU2Port acquires analog quantities such as voltage and current of the circuit breaker, as well as switch signals such as trip position, closing position, spring not stored energy, and low trip / closing pressure. After converting them into digital signals, they are sent to the relay protection distribution terminal device through messages. The acquisition unit MU2Port has two communication channels, and each communication channel sends a message. The analog and switch information contained in the message are the same.

[0040] The relay protection distribution terminal with two communication channels is connected to the two communication channels of the acquisition unit via two cables. It receives two messages from the acquisition unit. The CPU board determines whether the messages have been interfered with during transmission. If one message is interfered with, causing a verification error, the other, unaffected message is used for processing in the relay protection program. When the relay protection program determines that a fault in the distribution line requires tripping, if the tripping is initiated by the tripping relay configured in the relay protection distribution terminal, the tripping relay output is directly driven to trip. If a message is sent to the circuit breaker for tripping, the tripping signal is transmitted via two communication channels to the acquisition unit on the circuit breaker. The acquisition unit parses the message and drives its built-in relay to trip. The acquisition unit also verifies whether the two communication messages are interfered with, and only executes the tripping command in the correctly verified message. When one of the communication cables is interfered with and malfunctions, the message transmitted from the other uninterrupted cable can be used for relay protection judgment, receiving trip commands, etc., thereby improving the anti-interference and reliability of the digital relay protection distribution terminal.

[0041] More preferably, such as Figure 5 As shown, there are two acquisition units: a first acquisition unit MU1 and a second acquisition unit MU2 installed on the circuit breaker CB. Each unit has a communication channel, specifically a first acquisition unit communication channel G and a second acquisition unit communication channel H. These channels are respectively connected to a first terminal communication channel C and a second terminal communication channel D, forming independent communication channels for transmitting signals. The first acquisition unit MU1 and the second acquisition unit MU2 are installed at different locations on the circuit breaker. The first acquisition unit MU1 and the second acquisition unit MU2 can receive trip commands from the relay protection distribution terminal device via their respective independent communication channels, from the first terminal communication channel C and the second terminal communication channel D, respectively, tripping the circuit breaker where they are located. In specific implementation... Figure 5In this system, MU1 and MU2 each require only one communication channel. The relay protection distribution terminal with two communication channels is connected to the acquisition units MU1 and MU2 respectively via two communication cables. When the relay protection program determines that a fault in the distribution line requires tripping, if the tripping is initiated by the tripping relay configured in the relay protection distribution terminal, the tripping relay is directly driven. If a message is sent to the switch relay for tripping, the tripping signal is transmitted via the two communication channels to the two acquisition units on the switch circuit breaker. After parsing the message, the acquisition units drive their built-in relays to trip. The acquisition units only execute the tripping command in the correctly verified message. To improve anti-interference capabilities, acquisition units MU1 and MU2 are best installed at different locations on the switch circuit breaker and maintained at a certain distance. Figure 4 , Figure 5 The acquisition unit is also independent, which makes it more resistant to interference.

[0042] Based on the above scheme, it can be seen that the relay protection distribution terminal of the present invention has two channels located on the switch circuit breaker. The switch circuit breaker can use a data acquisition unit with two communication channels, or two data acquisition units can be installed on the switch circuit breaker to form two communication channels to transmit information respectively. When one of the messages in the two communication channels is interfered with and the verification fails, the relay protection program is calculated only based on the content of the other normal message.

[0043] The aforementioned acquisition unit can receive trip commands sent by the relay protection distribution terminal device and trip the circuit breaker where it is located.

[0044] More preferably, to improve the anti-interference and reliability of the digital relay protection distribution terminal, the first terminal communication channel C and the second terminal communication channel D adopt data block interleaving and redundant transmission technology. The relay protection program running on the CPU board B verifies, reassembles, and identifies distribution line faults in the messages transmitted by the first terminal communication channel C and the second terminal communication channel D using data block interleaving and redundant transmission technology, and controls tripping when a distribution line fault occurs.

[0045] The dual-protocol transmission means that the first terminal communication channel C and the second terminal communication channel D use different protocols to transmit messages.

[0046] More preferably, after receiving a message, the relay protection program first verifies the messages obtained through the first terminal communication channel C and the second terminal communication channel D. If one message fails verification while the other fails verification, the message with the correct verification is parsed for power distribution line fault identification. If both messages fail verification, either message is parsed for power distribution line fault identification. If both messages fail verification, the correct parts of the two messages are reassembled. If a correct and complete message can be obtained through reassembly, the reassembled message is used for power distribution line fault identification. If both messages fail verification and a correct and complete message cannot be obtained through reassembly, the protection is temporarily blocked, and a verification prompt message is issued.

[0047] If both message verifications fail, the parts of the two messages that passed verification will be reassembled. This includes at least the following situations:

[0048] 1) Reassembly during message interleaving: The first terminal communication channel C and the second terminal communication channel D each divide the message they have acquired into data blocks and transmit them in an interleaved order. When both messages have data block verification errors, the data blocks that have not been erroneous in the two channels are reassembled into a correct overall message.

[0049] 2) Reassembly during redundant data block transmission: The first terminal communication channel C and / or the second terminal communication channel D each divide the messages acquired by their respective channels into data blocks and transmit them in a redundant manner. Each data block is transmitted at least twice in each frame. If both data blocks in the two channels fail to verify, the data blocks of the messages that have passed verification are reassembled to obtain the correct overall message. For example, if there are two or more instances where the same data block in the same channel is interfered with and fails verification, the remaining data blocks of the other channel that have passed verification are parsed and reassembled. If a data block in one channel fails verification only once due to interference, the data blocks of the redundant transmission in that channel can be parsed and reassembled, or the data blocks of the other channel that have passed verification can be reassembled. Both of these situations may exist simultaneously in both data blocks.

[0050] 3) Reassembly during reassembly, data block redundancy, and message interleaving: The first terminal communication channel C and the second terminal communication channel D each divide the message obtained by their channel into data blocks and transmit them in an interleaved order and in a redundant manner. Each data block is transmitted at least twice in each frame of message and is transmitted in an interleaved order. When some data blocks are interfered with and fail to be verified, the remaining normally verified message data blocks are parsed and reassembled to obtain the correct overall message.

[0051] The relay protection program controls the tripping in the event of a power distribution line fault in the following ways: It directly drives the tripping relay configured in this device to trip; or, it transmits the tripping signal via communication messages through the first terminal communication channel C and the second terminal communication channel D to the acquisition unit on the circuit breaker. The acquisition unit verifies and parses the message before driving its built-in relay to trip. In other words, the tripping method can either use the tripping relay configured in the relay protection distribution terminal device to trip the switch via cable, or convert the tripping command into a digital quantity, transmit the message through the communication channel to the circuit breaker, and then have the circuit breaker parse the message and trip.

[0052] Embodiment 2 of the present invention provides an operation method for the above-mentioned relay protection distribution terminal device. The relay protection distribution terminal device of the present invention uses dual communication channels to receive messages and perform verification and switching, including the following steps:

[0053] Step 1: The relay protection distribution terminal device receives two messages through two communication channels;

[0054] CPU board B obtains the switch circuit breaker CB message collected by the acquisition unit on the switch circuit breaker CB through the first terminal communication channel C and the second terminal communication channel D respectively, and uses data block interleaving and redundant transmission technology to transmit the message simultaneously with dual protocols.

[0055] Step 2: CPU board B runs the relay protection program to verify, reassemble, and identify power distribution line faults in the messages transmitted through the first terminal communication channel C and the second terminal communication channel D using data block interleaving and redundant transmission technology, and controls the tripping when a power distribution line fault occurs.

[0056] The relay protection distribution terminal device verifies the correctness of the message. The message is generally sent as a combination of a set of data and a check code. The check code is calculated using the set of data as the calculation source according to a certain algorithm. When one or more of the data in the set changes, the check code calculated after the change will be inconsistent with the original check code, thus indicating that the set of data has changed. Therefore, if the message is interfered with and the data changes during transmission, the verification will fail according to the check code in the message, that is, the verification will fail.

[0057] If both message verifications are correct, one message is selected, and its analog quantity information such as voltage and current, as well as its switch quantity information such as trip position, closing position, spring not stored energy, and low trip / closing pressure, are parsed and used for relay protection program calculations. If one message verification fails while the other message is normal, only the normal message is used for relay protection program calculations, and the other message that fails verification is discarded.

[0058] In practice, the communication cables used to transmit messages can be based on the manufacturer's own internal protocol, or they can use the international standard IEC61850 protocol in the field of power system automation, such as the format specified by the IEC-60044-8 protocol or the IEC-61850-9-2 protocol.

[0059] In the above-mentioned dual-communication channel message receiving process, the probability of obtaining the correct message is increased compared to the single-channel message receiving case. However, there is still a situation where the messages received by both communication channels fail the verification. In this case, if no action is taken, the status information during this period can only be discarded, and the protection can be temporarily blocked. In order to improve the anti-interference capability of dual-communication channel message receiving, some improvements can be made in the specific implementation. The following are some improvement measures.

[0060] (1) Adopt dual-protocol simultaneous transmission technology. That is, two communication channels use different protocols to transmit information. For example, one communication channel uses the IEC-60044-8 protocol and the other communication channel uses the IEC-61850-9-2 protocol. Since the data transmission format and message transmission mechanism of different protocol organizations are different, when interference occurs, it is possible that both messages will fail the verification at the same time.

[0061] (2) Employing message interleaving and reassembly technology. This means that the data transmitted through the two communication channels is organized in an interleaved order and then transmitted separately. Digital relay protection distribution terminal units commonly use the IEC-60044-8 protocol for message transmission. The IEC-60044-8 protocol follows the FT3 frame format, which divides data into eight 16-bit data blocks plus one 16-bit checksum as a single data block. If 24 16-bit data blocks need to be transmitted, three data blocks are combined into a complete message frame for transmission. When using dual communication channels, to prevent simultaneous interference from rendering both data streams completely unusable, a single frame of data transmitted from each channel is interleaved according to a certain rule before being transmitted separately, such as... Figure 6 As shown, Figure 6 In the diagram, Blocks 1 to 3 represent the data blocks transmitted in the first channel of the dual communication channels, and Blocks 1' to 3' represent the data blocks transmitted in the second channel. The diagram only shows the data-related parts; other information such as header and trailer flags are not shown. D01 to D24 represent 24 data blocks, and C1 to C3 and C1' to C3' are the checksums for each data block. Assuming that both channels are simultaneously affected by interference during the transmission of the first data block, such as... Figure 6In the DISTURB signal, the first data block transmitted through both channels fails verification and becomes unusable. However, when the second and third data blocks are transmitted, the interference has passed. Moreover, due to the use of interleaved content transmission, the correct second and third data blocks from the first and second channels can be reconstructed into a complete and correct frame of data, thus improving the anti-interference effect.

[0062] (3) Employ data block redundancy transmission and reassembly technology. This involves increasing the redundancy of transmitted data blocks, transmitting each data block at least twice within a single message frame. Considering the characteristics of IEC-60044-8 protocol message transmission, and addressing short-term interference, if the interference only affects one or a portion of the data blocks, and if redundant transmission is employed (e.g., each data block is transmitted twice, for example, a message frame uses Block1, Block2, Block3 + a second transmission of Block1, Block2, Block3), when the two data blocks of the same data block are interfered with and fail verification, the entire message can still be obtained by parsing the remaining valid data blocks and reassembling them, thus improving anti-interference capabilities. However, increasing redundancy effectively doubles the amount of data transmitted per message frame. To complete message transmission within the specified time, a corresponding increase in transmission speed may be necessary. Therefore, if further redundancy is required, such as transmitting each data block three or more times within each message frame, the transmission speed needs to be increased accordingly. Data block redundancy transmission and reassembly technology is not limited to use in dual channels; it is also effective when used in single channels.

[0063] (4) Employ data block redundancy and message interleaving and reassembly techniques. This involves combining message interleaving and data block redundancy techniques, using dual communication channels, and ensuring that the data transmitted on each communication channel is redundant. Furthermore, the data transmitted on both communication channels is organized in an interleaved order and then transmitted separately, which can achieve a multiple redundancy effect and thus enhance the anti-interference effect.

[0064] With the above scheme, if one transmission cable is interfered with, resulting in a message verification error, the correct message can still be obtained using the other uninterrupted transmission cable for relay protection program calculations. Similarly, if some data blocks are interfered with, causing message verification errors, redundant uninterrupted data blocks can be used to recover the data. This improves the reliability of message transmission via cable, reduces the occurrence of malfunctions in the relay protection distribution terminal due to the inability to receive correct messages during power line faults, and thus enhances the anti-interference capability and reliability of the digital relay protection distribution terminal.

[0065] The beneficial effects of this invention are compared with those of the prior art:

[0066] This invention employs dual communication channels for message transmission. When one communication channel of the relay protection distribution terminal device is interfered with, resulting in a message verification error, the other uninterrupted transmission cable can still be used to obtain the correct message for relay protection program calculation, thereby increasing the probability of obtaining the correct message. Furthermore, by using different protocols for the dual communication channels, employing interleaved message content transmission, increasing the redundancy of transmitted data blocks, and combining interleaved and redundant transmission, the reliability of message transmission via cable is further improved. This reduces the occurrence of maloperation of the relay protection distribution terminal due to failure to receive the correct message when the distribution line is faulty, thereby improving the anti-interference and reliability of the digital relay protection distribution terminal.

[0067] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0068] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0069] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0070] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A relay protection distribution terminal device, comprising a housing, a CPU board, a first terminal communication channel, a second terminal communication channel, and a data acquisition unit, wherein the data acquisition unit is mounted on a circuit breaker, characterized in that: The number of acquisition units is two, namely a first acquisition unit and a second acquisition unit. The first acquisition unit is equipped with a first acquisition unit communication channel, and the second acquisition unit is equipped with a second acquisition unit communication channel. The first acquisition unit communication channel and the second acquisition unit communication channel are respectively connected to the first terminal communication channel and the second terminal communication channel to transmit messages independently. The CPU board is placed inside the casing and is connected to the acquisition unit installed on the switch circuit breaker through the first terminal communication channel and the second terminal communication channel respectively, so as to independently acquire the switch circuit breaker message collected by the acquisition unit. The message adopts data block interleaving and redundant transmission technology in the first terminal communication channel and the second terminal communication channel, and transmits simultaneously with dual protocols. The transmission strategy of the message in the dual channels is: the first terminal communication channel and / or the second terminal communication channel divide the message into data blocks and transmit them in different protocol interleaving order, and each data block is transmitted at least twice in each frame message. The CPU board runs a relay protection program to verify, reassemble, and identify power distribution line faults in the messages transmitted by the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology, and controls the tripping when a power distribution line fault occurs. The relay protection program verifies the messages transmitted through the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology. If one message fails to be verified while the other message passes verification, the normally verified message is parsed to identify the power distribution line fault. If both message verifications are normal, then either message is parsed to identify power distribution line faults. If both message verifications fail, the parts of the two messages that have passed verification are reassembled. If a correct and complete message can be obtained through reassembly, the reassembled message is used to identify the fault in the power distribution line. If both message verifications fail and a correct and complete message cannot be obtained through reassembly, the protection is blocked and a verification prompt message is issued.

2. The relay protection distribution terminal device according to claim 1, characterized in that: The number of acquisition units is one, and it is equipped with a first acquisition end communication channel and a second acquisition end communication channel. The first acquisition end communication channel and the second acquisition end communication channel are respectively connected to the first terminal communication channel and the second terminal communication channel to transmit messages independently.

3. The relay protection distribution terminal device according to claim 1, characterized in that: The first acquisition unit and the second acquisition unit are installed at different locations on the circuit breaker.

4. The relay protection distribution terminal device according to claim 1, characterized in that: The simultaneous transmission of dual protocols refers to the simultaneous transmission of messages using different protocols in the first terminal communication channel and the second terminal communication channel.

5. A relay protection distribution terminal device according to claim 1, characterized in that: Data block interleaving technology refers to the process by which the first terminal communication channel and the second terminal communication channel divide the message into data blocks and transmit them in an interleaved order.

6. A relay protection distribution terminal device according to claim 1, characterized in that: Data block redundancy transmission technology refers to the following: the first terminal communication channel and / or the second terminal communication channel divide the message into data blocks for transmission, and each data block is transmitted at least twice in each frame of message.

7. A relay protection distribution terminal device according to claim 1, characterized in that: The first terminal communication channel and the second terminal communication channel can simultaneously employ data block interleaving and redundant transmission techniques, specifically: The first terminal communication channel and the second terminal communication channel divide the message into data blocks for transmission, and each data block is transmitted at least twice in each frame of message, and the transmission is interleaved.

8. A relay protection distribution terminal device according to claim 1, characterized in that: The relay protection program controls the tripping in the event of a power distribution line fault in the following ways: directly driving the tripping relay configured in this device to trip; or, transmitting the tripping signal to the acquisition unit on the switch circuit breaker via communication messages through the first terminal communication channel and the second terminal communication channel respectively. After the acquisition unit verifies and parses the message, it drives its built-in relay to trip.

9. A method for operating a relay protection distribution terminal device according to any one of claims 1-8, characterized in that: The method includes: The CPU board obtains the switch circuit breaker messages collected by the acquisition unit on the switch circuit breaker through the first terminal communication channel and the second terminal communication channel respectively, and uses data block interleaving and redundant transmission technology to transmit messages simultaneously with dual protocols. The CPU board runs a relay protection program to verify, reassemble, and identify power distribution line faults in messages transmitted through the first terminal communication channel and the second terminal communication channel using data block interleaving and redundant transmission technology, and controls the tripping when a power distribution line fault occurs.

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