KR20220163801A - Apparatus for selecting bus on digital protection relay - Google Patents

Abstract

The present invention discloses a device for selecting a bus on a digital protection relay. The device for selecting a bus on a digital protection relay according to the present invention comprises: a PT module connected to a first to a second bus to be switched to a selected bus; a state input part for receiving the operating state of a first to a second disconnector installed on the first to the second bus, respectively; a selection control part for receiving the operating state of the first to the second disconnector from the state input part, selecting any one bus among the first to the second bus through the PT module depending on operating conditions to be switched, and outputting the state of the switched bus; and an output part for displaying the operating state of the first to the second disconnector, which is input through the state input part, and the operating state of the selection control part. Therefore, provided is a device for selecting a bus on a digital protection relay, wherein a 43PDA transfer switch can be realized in a digital protection relay using inner logic.

Description

Bus selection device of digital protection relay {APPARATUS FOR SELECTING BUS ON DIGITAL PROTECTION RELAY}

The present invention relates to a bus selector of a digital protection relay, and more particularly, in a double bus structure, it does not use a 43PDA changeover switch that automatically switches according to the operating state of the bus, but digitizes it and embeds it in a digital protection relay. It is about a bus selector of a digital protection relay that can be implemented with logic.

In general, a transmission line is very important because it serves as a transport path for transporting electric power in a power system. In the case of Korea, most of the transmission lines increase the reliability of power transmission through a two-line configuration, but the risk of failure is unavoidable due to the nature of distribution over a wide range of long distances (tens of km) including mountainous areas. Therefore, a failure of a transmission line means a blockage of the power transmission line, which may immediately cause a power outage.

Failures of these transmission lines take various forms. That is, there are types that disappear after instantaneously occurring, such as lightning strikes, and there are also failures that require maintenance, such as disconnection of transmission lines. There is a protection system that reduces the importance of these transmission lines, and various facilities such as protective relays and circuit breakers are configured together to detect failures in the transmission line and prevent the spread to other power phases.

Among them, the reclosing function divides the failures that occur in the transmission line into instantaneous failures and permanent failures. It plays a role in preventing electric shock accidents during work.

The background art of the present invention is disclosed in Republic of Korea Patent Registration No. 10-0991493 (2010.11.04. Announcement, Digital Protection Relay Providing Multiple Circuit Breaker Reclosing Function and Operation Method thereof).

In this way, the 154KV and 23KV buses of the substation, which consist of double transmission lines, are composed of a variable double bus method in which the operating bus is determined according to the position of the DS (Disconnector). In the double bus method, since it is very important in terms of protection relay to accurately acquire the voltage of the bus line actually in operation and use it for calculation, as shown in FIG. Using DS input information, it acquires the voltage of the actual operating bus and transmits it to the protection relay.

Here, the changeover switch acquires operation information of both busses DS, selects a busbar in operation by driving a switching motor according to operating conditions, and outputs the voltage of the selected busbar.

However, switchover switch is a cause of defects due to incorrect wiring due to complicated inspection or circuit wiring according to the configuration of the hardware method that selects the bus by driving the switching motor, and in case of defective DS contact and circuit connection, or defective switching motor, There is a problem of selecting an inaccurate voltage that does not match the bus operating conditions, and there is a problem that causes erroneous operation or re-closing failure of a distance relay using voltage as an input source.

In addition, the 43PDA changeover switch drives the changeover motor in a hardware method to transfer the bus, so it takes about 4 to 5 seconds to switch the voltage, so the operation of the protective relay is blocked during this time to protect the power system. There are problems that can't be done.

The present invention has been made to improve the above problems, and an object of the present invention according to one aspect is not to use a 43PDA changeover switch that automatically switches according to the operating state of a bus in a double bus structure, but to digitalize it by digitizing it. It is to provide a bus selector of a digital protection relay that is embedded in the protection relay and can be implemented with internal logic.

An apparatus for selecting a bus of a digital protection relay according to an aspect of the present invention includes a PT module that is connected to first and second buses and switches to a selected one of the buses; a state input unit for receiving operating states of the first to second disconnectors installed in the first to second buses, respectively; A selection control unit that receives the operating state of the first to second disconnectors from the state input unit, selects and switches one of the first to second buses through the PT module according to operating conditions, and outputs the state of the switched bus. ; and an output unit displaying the operation status of the first and second disconnectors input through the status input unit and the operation status of the selection control unit.

In the present invention, the selection control unit is characterized in that it receives the operating states of the first and second disconnectors, determines contact failure based on each contact state, and gives a warning through an output unit.

In the present invention, the first to second disconnectors output mutually exclusive contact states, and the selection control unit determines the mutually exclusive contact states and outputs a contact failure warning.

In the present invention, the selection control unit receives the operating state of the first to second disconnectors, selects the first bus when the first disconnector is closed, and selects the second bus when the second disconnector is closed. .

In the present invention, the selection control unit is characterized in that when the second disconnector is input in a state in which the first bus is selected, the first disconnector is cut off and then the second bus is selected.

In the present invention, the selection control unit is characterized in that when the first disconnector is input in a state in which the second bus is selected, the first bus is selected after the second isolator is cut off.

The bus selection device of a digital protection relay according to one aspect of the present invention does not use a 43PDA changeover switch that automatically switches according to the operation status of a bus in a double bus structure, but by digitizing it, it can be embedded in a digital protection relay and implemented as internal logic. Not only can the purchase cost be reduced by dismantling the changeover switch by the changeover motor, but also the occurrence of defects due to incorrect wiring and the occurrence of defects in the changeover motor due to hardware method can be reduced and the changeover time of the bus line is minimized can do.

1 is a circuit configuration diagram showing a general 43PDA switching switch.
2 is a block diagram showing a bus selection device of a digital protection relay according to an embodiment of the present invention.
3 is a configuration diagram showing a connection state of a disconnector in a bus selection device of a digital protection relay according to an embodiment of the present invention.
4 is a table showing operating conditions of a bus selection device of a digital protection relay according to an embodiment of the present invention.
5 is a diagram showing a contact failure monitoring logic in a bus selection device of a digital protection relay according to an embodiment of the present invention.

Hereinafter, a bus selection device of a digital protection relay according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

2 is a block configuration diagram showing a bus selection device of a digital protection relay according to an embodiment of the present invention, and FIG. 3 shows a connection state of a disconnector in a bus selection device of a digital protection relay according to an embodiment of the present invention. 4 is a table showing operating conditions of a bus selection device of a digital protection relay according to an embodiment of the present invention, and FIG. 5 is a table showing a bus selection device of a digital protection relay according to an embodiment of the present invention This is a diagram showing the contact failure monitoring logic.

As shown in FIG. 2, the bus selection device of a digital protection relay according to an embodiment of the present invention may include a PT module 10, a status input unit 20, a selection control unit 30, and an output unit 40. can

The PT module 10 is connected to the first and second bus lines #1 BUS and #2 BUS, respectively, and can output the voltage of the selected bus line by switching to one of the selected bus lines.

The state input unit receives operating states of the first and second disconnectors #1 DS and #2 DS respectively installed in the first and second buses #1 BUS and #2 BUS.

Here, the first disconnector (#1 DS) is selected when operating by selecting the first bus (#1 BUS), and the second disconnector (#2 DS) is operated by selecting the second bus (#2 BUS). You choose when you want to.

At this time, the first disconnector (#1 DS) and the second disconnector (#2 DS) are composed of a switch 89A and a switch 89B having two contacts a and b, respectively, as shown in FIG. They are placed intersecting each other on the mothership. And, the two contact points a and b are mutually exclusive.

Therefore, the first bus (#1 BUS) can be operated only when the first disconnector (#1 DS) is turned on and the second disconnector (#2 DS) is turned off, and the first disconnector (#1DS) is turned off. The second bus (#2 BUS) can be operated only when the 2 disconnector (#2DS) is turned on.

The selection control unit 30 receives the operating states of the first and second disconnectors (#1 DS and #2 DS) from the state input unit 20 and the first and second buses through the PT module 10 according to operating conditions. (#1 BUS, #2 BUS) can be selected and switched, and the status of the switched bus can be output.

As shown in FIG. 4, the selection control unit 30 displays the states of the 89A a and b contacts and the states of the 89B a, The state of the b contact can be logically determined and the first bus line (#1 BUS) or the second bus line (#2 BUS) can be selected and switched through the PT module 10.

Here, 89A_a is the a contact of the first disconnector (#1 DS), which is normally open, and is an auxiliary contact of the disconnector that is closed when closing, and 89A_b is the b contact of the first disconnector (#1 DS), which is normally closed but is closed when closing. 89B_a is the auxiliary contact of the disconnector that is open, and 89B_a is the a contact of the second disconnector (#2 DS), which is normally open, but is closed when closed, and 89B_b is the b contact of the second disconnector (#2 DS), which is normally It is a disconnector auxiliary contact that is closed and then opened when closed.

That is, the first bus (#1 BUS) voltage selection condition is that the 89A_a contact is closed (1), the 89A_b contact is open (0), the 89B_a contact is open (0), and the 89B_b contact is closed. #1 BUS) voltage is input.

In addition, the second bus (#2 BUS) voltage selection condition is that the 89B_a contact is closed (1), the 89B_b contact is open (0), the 89A_a contact is open (0), and the 89A_b contact is closed. #2 BUS) voltage is input.

On the other hand, the selection control unit 30 determines the mutually exclusive contact state of the first and second disconnectors #1 DS and #2 DS, and when they are operated identically, the contact failure occurs through the output unit 40 as a contact failure. can warn

That is, as shown in FIG. 5, the same value is input even though mutually exclusive values are input to the a and b contacts of 89A through XNOR logic, or the same value is input even though mutually exclusive values are input to the a and b contacts of 89B. When a value is input, the selection control unit 30 may determine it as a contact failure.

This is to prevent both bus line voltages from being input (selected) at the same time. If both bus line voltages are input at the same time, a short circuit may occur, which may cause burnout or fire of the protective relay.

On the other hand, when the first to second disconnectors (#1 DS, #2 DS) of the wool wire are in the closed state, the first bus line (# 1 BUS) voltage is used for protection relay operation (even if the second bus (#2 BUS) voltage is used), and both the first and second disconnectors (#1 DS, #2 DS) of both buses are in the OFF state Since there is no voltage of the selected bus line, the operation of the protection relay is blocked.

In this way, the selection control unit 30 receives the operating states of the first and second disconnectors #1 DS and #2 DS, and operates the first bus line #1 BUS when the first disconnector #1 DS is turned on. and if the second disconnector (#2 DS) is closed, the second bus (#2 BUS) can be selected.

In addition, the selection control unit 30, when the second disconnector (#2 DS) is turned on while the first bus (#1 BUS) is selected, after the first disconnector (#1 DS) is cut off, the second bus (#2) BUS) can be selected, and if the first disconnector (#1 DS) is turned on while the second bus (#2 BUS) is selected, the second disconnector (#2 DS) is cut off and the first bus (#1 BUS) is disconnected. ) can be selected.

The output unit 40 may display the operation status of the first and second disconnectors #1 DS and #2 DS input through the state input unit 20 and the operation status of the selection control unit 30 .

As described above, according to the bus selection device of a digital protection relay according to an embodiment of the present invention, it does not use a 43PDA changeover switch that automatically switches according to the operating state of a bus in a double bus structure, but digitizes it, thereby providing a digital protection relay. It can be built into the internal logic and can be implemented as internal logic, and the switching switch by the switching motor can be removed, which can reduce the purchase cost as well as reduce the occurrence of defects and defective switching motors due to misconnection of circuit wiring by hardware method. and the switching time of the bus line can be minimized.

Implementations described herein may be embodied in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed only in the context of a single form of implementation (eg, discussed only as a method), the implementation of features discussed may also be implemented in other forms (eg, an apparatus or program). The device may be implemented in suitable hardware, software and firmware. The method may be implemented in an apparatus such as a processor, which is generally referred to as a processing device including, for example, a computer, microprocessor, integrated circuit, programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, personal digital assistants ("PDAs") and other devices that facilitate communication of information between end-users.

The present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. will understand

Therefore, the true technical protection scope of the present invention should be determined by the claims below.

10: PT module
20: state input unit
30: selection control unit
40: output unit

Claims (6)

a PT module that is connected to the first to second buses and switches to a selected one of the buses;
a state input unit for receiving operating states of the first and second disconnectors respectively installed in the first and second buses;
It receives the operating state of the first to second disconnectors from the state input unit, selects and switches one of the first to second bus lines through the PT module according to operating conditions, and displays the state of the switched bus line. a selection control unit that outputs; and
and an output unit for displaying the operation status of the first to second disconnectors input through the status input unit and the operation status of the selection control unit.
The bus selection of a digital protection relay according to claim 1, wherein the selection control unit receives the operating states of the first and second disconnectors, determines contact failure based on each contact state, and issues a warning through an output unit. Device.
The digital protection relay according to claim 1, wherein the first and second disconnectors output mutually exclusive contact states, and the selection control unit determines the mutually exclusive contact states and outputs a contact failure warning. 's mothership selector.
The method of claim 1, wherein the selection control unit receives the operating state of the first and second disconnectors, selects the first bus when the first disconnector is closed, and selects the second bus when the second disconnector is closed. A bus selector of a digital protection relay, characterized in that for doing.
The bus selection device of a digital protection relay according to claim 1, wherein the selection control unit selects the second bus after the first isolator is cut off when the second disconnector is turned on while the first bus is selected.
The bus selection device of a digital protection relay according to claim 1, wherein the selection control unit selects the first bus line after the second disconnector is cut off when the first disconnector is turned on while the second bus is selected.

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