JP2022052372A - Relay device and power receiving system - Google Patents

Abstract

To provide a relay device with a reduced number of components.SOLUTION: According to an embodiment, a relay device is applicable to a power receiving system for receiving power by a spot network power receiving method from a first line protected by a first circuit breaker, a second line protected by a second circuit breaker, and a third line protected by a third circuit breaker. The relay device includes a logic circuit. The logic circuit outputs a trip command to the first circuit breaker when an undervoltage event occurs in the first line. Furthermore, the logic circuit outputs the trip command to the first circuit breaker when the under-voltage event occurs in the second line and the under-voltage event occurs in the third line in a state in which no under-voltage event has not occurred in the first line.SELECTED DRAWING: Figure 4

Description

Embodiments of the present invention relate to relay devices and power receiving systems.

The spot network power receiving method is known as a highly reliable power supply method, and is widely used as a power receiving method in overcrowded areas such as urban areas. For example, in the three-line power receiving type network power receiving system, power supply can be continued without limiting the load even if one line fails. However, when a two-line power failure occurs, a network relay controls the power receiving circuit breaker of the remaining line to trip (remaining line trip) in order to prevent an overload. The network relay is a key device for maintaining stable operation in the spot network power receiving method.

Satoshi Yamamoto, Naoki Wakamatsu, Satoshi Ishida, "New HRE190 Network Relay", Toshiba Review Vol. 70 No. 1 (2015), p44-47

The network relay is mounted on the surface of a switchgear, for example. Existing network relays have basic protection functions, but rely on an external circuit (residual line trip circuit) for residual line trip control. Some measures are required to reduce the number of parts such as switchgear.
Therefore, an object is to provide a relay device and a power receiving system with a reduced number of parts.

According to the embodiment, the relay device receives spot network power from the first line protected by the first circuit breaker, the second line protected by the second circuit breaker, and the third line protected by the third circuit breaker. It is a relay device applicable to a power receiving system that receives power by a method. This relay device includes a logic circuit. This logic circuit outputs a trip command to the first circuit breaker when an undervoltage event occurs in the first line. Further, this logic circuit is a first circuit breaker when an undervoltage event occurs in the second line and an undervoltage event occurs in the third line while no undervoltage event has occurred in the first line. Outputs a trip command to.

FIG. 1 is a diagram showing an example of a power receiving system to which a spot network power receiving method is applied. FIG. 2 is a diagram showing an example of a residual line trip circuit in a network relay. FIG. 3 is a control flow diagram for explaining the operation of the circuit shown in FIG. FIG. 4 is a functional block diagram showing an example of the network relay 101 according to the first embodiment. FIG. 5 is a schematic diagram showing a mode in which network relays 101 to 103 communicate with each other by the wired interface 14a. FIG. 6 is a schematic diagram showing a mode in which network relays 101 to 103 communicate with each other by the wireless interface 14b. FIG. 7 is a functional block diagram showing an example of the network relay 101 according to the third embodiment. FIG. 8 is a diagram showing an example of connection between lines S1 to S3 and network relays 101 to 103 in the power receiving system according to the third embodiment. FIG. 9 is a diagram showing the connection between the lines S1 to S3 and the network relays 101'to 103' in the existing power receiving system.

Hereinafter, embodiments will be described with reference to the drawings. Some embodiments shown below exemplify an apparatus or system for embodying the technical idea of the present invention, and the technical idea of the present invention is specified by the shape, structure, arrangement, etc. of the components. It is not something that will be done.

FIG. 1 is a diagram showing an example of a power receiving system to which a spot network power receiving method is applied. In FIG. 1, the electric power received from the line S1, the line S2, and the line S3 of the special high voltage system from the power system 100, respectively, is demanded in each of the lines S1 to S3 via the power receiving disconnector 1 and the network transformer 2. Be drawn to the house side. A network protector is installed in the system on the secondary side of the network transformer 2.

The network protector of the line S1 includes a spot network relay (network relay) 101 and a protector circuit breaker 21. The network relay 101 is connected to the system secondary side via the current transformer 3, the network transformer 5, and the network current transformer 6. Further, an instrument transformer 4 is provided, for example, between the current transformer 3 and the network transformer 5.

The network protector of the line S2 includes the network relay 102 and the protector circuit breaker 22, and the line S2 has the same configuration as the line S1. Further, the network protector of the line S3 includes the network relay 103 and the protector circuit breaker 23, and the line S3 has the same configuration as the line S1. That is, the line S1 is mainly protected by the protector circuit breaker 21, the line S2 is mainly protected by the protector circuit breaker 22, and the line S3 is mainly protected by the protector circuit breaker 23. Then, each of the lines S1 to S3 is connected to the network bus line 200 in parallel and operated.

The network relays 101 to 103 have each function of non-voltage input, differential voltage input, and reverse power cutoff. These functions are the three principle elements that are the key to the automatic operation of the spot network power receiving method. For example, when two of the three lines fail, a trip command for operating the protector circuit breaker of the own line is output from the network relay of the remaining line. As a result, the remaining line trip control is immediately executed.

FIG. 2 is a diagram showing an example of a residual line trip circuit in a network relay. In FIG. 2, it is assumed that the line S1 and the line S2 are in a power failure state, and the line S3 is in an operating state. When the lines S1 and S2 are in a power failure state, 27S1 and 27S2 operate, and a current flows through the closed a contact. Since the line S3 is in the operating state, the 27S3 does not operate and a current flows through the closed b contact. By the operation of 27S1, 27S2, 27S3, it is determined that the two lines are in a power failure state, 27ST is operated, and the a contact is closed. After that, the auxiliary relays TX-S1, TX-S2, and TX-S3 operate, and trip commands are collectively output to the protector breakers 21, 22, 23 of each line. After the trip command is output, the timer relay 27STT operates and the b contact opens to restore the TX-S1, TX-S2, and TX-S3.

FIG. 3 is a control flow diagram for explaining the operation of the circuit shown in FIG. The network relays 101, 102, 103 have a function as an undervoltage relay (27 relay), and include an operation signal of 27 relays of each line S1, S2, S3, an electric wire, a timer relay, an auxiliary relay, and the like. By passing it through the circuit, it is determined that there is a two-line power failure, and a trip command is issued for all lines.

The 27 relay operates by inputting the voltage of each line S1 to S3 in the event of a power failure (when the voltage falls below the set voltage value). When operating, the a contact closes and the b contact opens. During normal operation (when the set voltage value is exceeded), it does not operate, the a contact opens and the b contact closes.

As shown in FIG. 3, the operation signals of the network relays 101, 102, and 103 are branched into three and input to the three three-input AND circuits A1, A2, and A3. However, one of the three inputs of each AND circuit is a NOT signal (27 without operation) N1, N2, N3. That is, among the inputs to the AND circuit A1, the NOT signal (27S3 not operating) N1 of the network relay 103 is input. Of the inputs to the AND circuit A2, the NOT signal (27S2 not operating) N2 of the network relay 102 is input. Of the inputs to the AND circuit A3, the NOT signal (27S1 not operating) N3 of the network relay 101 is input.

The outputs of the AND circuits A1, A2, and A3 are input to the OR circuit O1, and the trip command is output via the timer circuit T. This trip command is input to all protector circuit breakers 21, 22, 23 (52S1 trip, 52S2 trip, 52S3 trip). With such a configuration, when an undervoltage event (27) occurs in any two of the lines S1, S2, and S3, all the lines including the remaining lines are cut off. This completes the remaining line trip control.

[First Embodiment]
FIG. 4 is a functional block diagram showing an example of the network relay 101 according to the first embodiment. The configuration of the network relays 102 and 103 is the same. The network relay 101 includes an operation unit 11, a display unit 12, an output unit 13, a communication unit 14, a processor 15, and a memory 16. These are connected to each other by a bus 17.

The operation unit 11 accepts an operation by the user. The display unit 12 visually displays various information such as the occurrence of an alarm. The output unit 13 outputs a trip command for operating the protector circuit breaker 21 of the own line S1 in response to an instruction from the processor 15. The communication unit 14 communicates with other network relays 102 and 103 by the wired interface 14a or the wireless interface 14b. The processor 15 is a semiconductor arithmetic circuit that performs arithmetic processing by the program 16a stored in the memory 16. The processor 15 and the memory 16 form a logic circuit 18. As described above, the logic circuit 18 outputs a trip command to the protector circuit breaker 21 as the first circuit breaker when an undervoltage event occurs in the line S1.

By the way, the processor 15 includes a detection function 15a and a residual line trip function 15b as processing functions according to the embodiment.
The detection function 15a detects the output of the trip command by the other network relay 102 and the output of the trip command by the network relay 103.
The remaining line trip function 15b outputs a trip command to the protector circuit breaker 21 when the detection function 15a detects the output of the trip command by the network relay 102 and the output of the trip command by the network relay 103.

FIG. 5 is a schematic diagram showing a mode in which network relays 101 to 103 communicate with each other by the wired interface 14a. In the mode shown in FIG. 5, 27 signals are exchanged between the network relays 101 and 103 by connecting the network relays 101 to 103 with a wire (electric wire). A two-line power failure is determined in each line S1 to S3, the network relay 101 (27S1) is sent to the protector breaker 21 of S1, the network relay 102 (27S2) is sent to the protector breaker 22 of S2, and the network relay 103 (27S3). Outputs a trip command to the protector circuit breaker 23 of S3, respectively.

As described above, in the first embodiment, the network relays 101 to 103 are provided with the logic circuit 18 including the processor 15 and the memory 16, and the remaining line trip control function is implemented by the processor 15. In addition, 27 signals are exchanged with other network relays by the wired interface 14a. As a result, the number of parts such as control supplies and wiring can be significantly reduced, and the manufacturing cost can be reduced.

In addition, the wired connection makes it less susceptible to noise. Furthermore, during maintenance, the number of replacement points can be reduced, and the probability of wiring errors and failures can be minimized. From these facts, according to the first embodiment, it becomes possible to provide a relay device and a power receiving system with a reduced number of parts.

[Second Embodiment]
FIG. 6 is a schematic diagram showing a mode in which network relays 101 to 103 communicate with each other by the wireless interface 14b. In the embodiment shown in FIG. 6, 27 signals are exchanged between the network relays 101 and 103 by connecting the network relays 101 to 103 wirelessly (radio waves). A two-line power failure is determined in each line S1 to S3, the network relay 101 (27S1) is sent to the protector breaker 21 of S1, the network relay 102 (27S2) is sent to the protector breaker 22 of S2, and the network relay 103 (27S3). Outputs a trip command to the protector circuit breaker 23 of S3, respectively.
According to the above configuration, since the 27 signals are connected by wireless transmission, wiring between network relays can be reduced and the risk of disconnection can be eliminated. That is, according to the second embodiment, in addition to the same effect as that of the first embodiment, it is possible to further reduce the wiring arrangement.

[Third Embodiment]
FIG. 7 is a functional block diagram showing an example of the network relay 101 according to the third embodiment. In FIG. 7, the blocks common to FIG. 4 are designated by the same reference numerals, and only different parts will be described here.
The network relay 101 of FIG. 7 includes a voltage input unit 19 instead of the communication unit 14 (FIG. 4). Further, the processor 15 includes a detection function 15c instead of the detection function 15a.

The voltage input unit 19 is connected to the lines S1, S2, S3 via the network modifier 5, respectively, and inputs the voltage of the divided lines S1, S2, S3.
The detection function 15c detects the occurrence of an undervoltage event in the line S2 and the occurrence of an undervoltage event in the line S3 via the voltage input unit 19. The residual line trip function 15b outputs a trip command to the protector circuit breaker 21 when the occurrence of the undervoltage event in the line S2 and the occurrence of the undervoltage event in the line S3 are detected.

As shown in FIG. 8, in the third embodiment, the (divided) voltage of each line S1 to S3 is taken into each of the network relays 101, 102, 103. That is, by inputting the voltages of the three lines S1 to S3 to each of the network relays 101 to 103, the presence or absence of a two-line power failure is determined. That is, according to the above configuration, the network relays 101 to 103 can individually and more directly determine the two-line power failure without sharing the 27 signals between the network relays 101 to 103. Therefore, the wiring between the network relays 101 to 103 can be reduced.

As shown in FIG. 9, in the existing power receiving system, only the voltage of the own line is input to each network relay 101'to 103'. Therefore, each network relay can know only the power failure information of one line, and it is necessary to construct a two-line power failure determination circuit outside the network relay.

On the other hand, according to the third embodiment, in addition to obtaining the same effects as those of the first and second embodiments, it is possible to reduce the wiring between the plurality of network relays.

The present invention is not limited to the above embodiment. For example, the physical quantity to be detected by each network relay 101 to 103 is not limited to voltage, but may be current. Further, not only the undervoltage event may be detected, but also an excessive voltage value or current value may be detected.

Although embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... power receiving circuit breaker, 2 ... network transformer, 3 ... current transformer, 4 ... instrument transformer, 5 ... network transformer, 6 ... network current transformer, 11 ... operation unit, 12 ... display unit, 13 ... Output unit, 14 ... Communication unit, 14a ... Wired interface, 14b ... Wireless interface, 15 ... Processor, 15a ... Detection function, 15b ... Remaining line trip function, 15c ... Detection function, 16 ... Memory, 16a ... Program, 17 ... Bus, 18 ... Logic circuit, 19 ... Voltage input unit, 21, 22, 23 ... Protector circuit breaker, 100 ... Power system, 101, 102, 103 ... Network relay, 102 ... Network relay, 103 ... Network relay, 200 ... Network Bus line, S1 to S3 ... line, S1, S2, S3 ... line.

Claims (7)

Applicable to power receiving systems that receive power from the first line protected by the first circuit breaker, the second line protected by the second circuit breaker, and the third line protected by the third circuit breaker by the spot network power receiving method. In the relay device
A logic circuit that outputs a trip command to the first circuit breaker when an undervoltage event occurs in the first line is provided.
The logic circuit is
When the undervoltage event occurs in the second line and the undervoltage event occurs in the third line in a state where the undervoltage event does not occur in the first line, the first circuit breaker is used. A relay device that outputs trip commands. When the power receiving system includes a second relay device that outputs a trip command to the second circuit breaker and a third relay device that outputs a trip command to the third circuit breaker.
A communication unit that communicates with the second relay device and the third relay device is further provided.
The logic circuit is
Memory for storing programs and
It includes a processor that executes the instructions described in the program.
The processor
A detection function for detecting the output of the trip command by the second relay device and the output of the trip command by the third relay device, and
The claim is provided with a residual line trip function for outputting the trip command to the first circuit breaker when the output of the trip command by the second relay device and the output of the trip command by the third relay device are detected. Item 1. The relay device according to item 1. The relay device according to claim 2, wherein the communication unit communicates with the second relay device and the third relay device via a wired interface. The relay device according to claim 2, wherein the communication unit communicates with the second relay device and the third relay device via a wireless interface. Each of the second line and the third line is further provided with a voltage input unit connected via a transformer.
The logic circuit is
Memory for storing programs and
It includes a processor that executes the instructions described in the program.
The processor
A detection function that detects the occurrence of an undervoltage event on the second line and the occurrence of an undervoltage event on the third line via the voltage input unit.
It is provided with a residual line trip function that outputs the trip command to the first circuit breaker when the occurrence of the undervoltage event on the second line and the occurrence of the undervoltage event on the third line are detected. The relay device according to claim 1. In a power receiving system that receives power using the spot network power receiving method
The first line protected by the first circuit breaker,
The second line protected by the second circuit breaker,
The third line protected by the third circuit breaker,
Equipped with a relay device,
The relay device is
A logic circuit that outputs a trip command to the first circuit breaker when an undervoltage event occurs in the first line is provided.
The logic circuit is
When the undervoltage event occurs in the second line and the undervoltage event occurs in the third line in a state where the undervoltage event does not occur in the first line, the first circuit breaker is used. A power receiving system that outputs trip commands. A second relay that outputs a trip command to the second circuit breaker,
The third circuit breaker is further provided with a third relay that outputs a trip command.
The relay device is
A communication unit that communicates with the second relay and the third relay is further provided.
The logic circuit is
Memory for storing programs and
It includes a processor that executes the instructions described in the program.
The processor
A detection function that detects the output of the trip command by the second relay and the output of the trip command by the third relay.
6. The remaining line trip function for outputting the trip command to the first circuit breaker when the output of the trip command by the second relay and the output of the trip command by the third relay are detected is provided. The power receiving system described in.

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