JP3129759B2 - Digital type current differential protection relay device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates are each provided corresponding to each terminal of the multi-terminal transmission line including a π shape branch terminals, mutual
The present invention relates to a digital type current differential protection relay device for transmitting and receiving current value information and disconnection switch opening / closing information for system protection.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional protection relay device of this kind applied to a three-terminal transmission line having a π-shaped branch.

[0003] In the figure, in a three-terminal transmission line composed of an A terminal, a B terminal and a C terminal, the C terminal has a π-shaped branch configuration. Among them, the disconnector 13 and the circuit breaker 15 are connected in series to the A terminal, and the disconnector 23 and the circuit breaker 25 are connected in series to the B terminal. On the other hand, A
A transformer 36 and a circuit breaker 35 are connected in series at the junction between the end-side disconnector 33A and the B-end-side disconnector 33B. In addition, digitally corresponding to A terminal, B terminal and C terminal
Type current differential protection relay device (hereinafter simply referred to as current-operated relay
-Abbreviated as device) 11, 21, and 31 are provided.

Here, a secondary circuit current of the current transformer 10 for detecting a current passing through the disconnector 13 is introduced into the current differential relay device 11 of the A terminal, and an auxiliary contact of the disconnector 13 (not shown). ) Is obtained. Similarly, B
A secondary circuit current of the current transformer 20 for detecting a current passing through the disconnector 23 is introduced into the terminal current differential relay device 21,
Opening / closing information by an auxiliary contact (not shown) of the disconnector 23 is fetched. The current differential relay device 31 of the C terminal has a current transformer 30 for detecting a current passing through the disconnectors 33A and 33B, respectively.
A and 30B secondary circuit currents are introduced and disconnector
Each switching information by the auxiliary contacts (not shown) of 33A and 33B is taken.

Also, current differential relay devices 11, 21 and 31
Transmits and receives current value information and disconnection switch opening and closing information to and from each other via the communication devices 12, 22, and 32, respectively. Then, based on the current value information of all the terminals and the switching information of the disconnecting switch, the faulty section and the breaking section between all the terminals are determined, and the circuit breakers 15, 25, and 35 at their own ends are opened based on the determination results. .

[0006] In this case, as a specific method of discriminating the accident section and the interruption section, each of the current transformers 10, 20, 30A, 30 is used.
The secondary circuit current of B is I ₁₀ , I ₂₀ , I _30A , I
_{As 30B} , follow the calculation in the table below.

[0007]

[Table 1] On the other hand, there is no protection relay device applied to transmission lines having four or more terminals with a π-shaped branch at present, but by the way,
As a configuration applied to the transmission line of the terminal, a configuration shown in FIG. 6 can be considered. Here, the C terminal and the D terminal are π-shaped branches.

In the terminal D, a transformer is provided at a junction between the disconnector 43A on the A end and the disconnector 43B on the B end.
46 and the circuit breaker 45 are connected in series. The current differential relay device 41 provided corresponding to the D terminal has a current transformer 40A for detecting the current flowing through the disconnectors 43A and 43B, respectively.
, 40B are introduced and the disconnector 4
Each opening / closing information by the auxiliary contacts (not shown) of 3A and 43B is taken in. Further, the current differential relay device 41 transmits / receives current value information and disconnection switch opening / closing information to / from another current differential relay device via the communication device 42, and similarly to the other, the fault section between all terminals and The interruption section is determined.

[0009]

In the current-operated relay device described above, each terminal can determine whether the terminal is inside or outside the protection system, that is, what is called an accident section, depending on the switching condition of the disconnector. Judge whether the accident is between the terminals of
There is a problem that a so-called cutoff section cannot be determined for proper cutoff. Hereinafter, this will be described with reference to FIG.

In FIG. 5, it is assumed that the disconnector 33A is open. In this state, the current transformers 10 and 30A
If an accident occurs at the point f ₁ between the points, the accident point f ₁
The fault current flows through. Therefore, a current corresponding to this fault current flows through the secondary circuit of the current transformer 10, and this current is introduced into the current differential relay device 11. The current transformer 20 at the B terminal and the current transformer 30B at the C terminal are not affected by an accident due to the opening of the disconnector 33A, and the normal secondary circuit current is passed through the current differential relay device 21 and the current difference. To the dynamic relay device 31. On the other hand, no current flows from the C terminal to the current transformer 30A of the C terminal due to the opening of the disconnector 33A, and the secondary circuit current becomes zero.

Based on the above information, the current differential relay device 1
The terminals 1, 21, and 31 determine an accident between the terminal A and the terminal C, and among them, the current differential relay device 11 of the terminal A outputs an opening command to open the circuit breaker 15. However, the current differential relay device 21 at the B terminal and the current differential relay device 31 at the C terminal do not output a circuit breaker open command, and therefore both the circuit breakers 25 and 35 maintain the closed state. The current transformer 20
And even if an accident occurs at f ₂ points between the current transformer 30B, in the same manner as this, determination of the fault section and cut-off section is performed.

[0012] However, when the disconnector 33A is in the open circuit state, when an accident occurs in f ₃ points between the current transformer 30A and disconnector 33A, unlike the operation described above, the current differential relay device Malfunctions. That is, if an accident occurs at _three points f, current flowing from the terminal A to the _three points f is current transformer 10
The secondary circuit current is detected by the current differential relay device 11
Will be introduced. The C terminal current transformer 30A also detects this fault current and introduces the secondary circuit current into the current differential relay device 31. In this case, regardless of the condition that the current differential relay device 31 disconnectors 33A is in the open circuit condition, the current transformer 30A
The secondary circuit current is processed as an increased current in the secondary circuit of the current transformer 30B. On the other hand, the current transformer 20 at the B terminal is not affected by the accident because of the condition that the disconnector 33A is open.

Based on the above information, the current differential relay device 11
Outputs an open command to the circuit breaker 15 to open the circuit breaker 15. Although the condition that the disconnector 33A is open is satisfied , regardless of this condition, the current values flowing through the current transformer 20 and the current transformer 30B are different from each other. Also, the current differential relay device 31 outputs an open command to the circuit breaker 35 to open the circuit breaker 35. That is, although the C terminal can be supplied with power as usual without being affected by an accident, the circuit breaker 35 malfunctions.

This means that between the current transformer 10 and the disconnector 13,
Between current transformer 20 and disconnector 23, current transformer 30B and disconnector 33
The same applies when an accident occurs during B. Hereinafter, this accident is referred to as a blind spot accident.

However, in the conventional protection relay device shown in FIG. 5, it is impossible to determine the cutoff section for a blind spot accident, and the protection relay corresponding to the four-terminal π-type branch transmission line shown in FIG. The same was true of the relay device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to provide a protection device capable of reliably determining a cutoff section even if an accident occurs between a current transformer and a disconnector of each terminal. The purpose is to obtain a relay device.

[0017]

According to the present invention, there is provided a multi-terminal transmission line including a π-type branch terminal, which is provided at the π-type branch terminal of the multi-terminal transmission line, and takes in current value information at its own end and disconnection switch opening / closing information. To the other end, and receives the current value information of the other end and the switching information of the disconnector, and based on each current value information of the own end and the other end and the switching information of the disconnector, all terminals Thing
The discrimination between the dead section and the cut-off section is performed.
In a digital type current differential protection relay device that opens its own circuit breaker in response , the own end disconnector sets the current value of the open transmission line to zero, and the own end disconnector disconnects the closed transmission line. Transmission selection means for transmitting the current value information as it is, and reception processing means for receiving the current value information by setting the current value of the transmission line at the other end where the disconnector is open to zero and receiving the current value information It is.

[0018]

According to the present invention, when the disconnector at the end is opened,
Assuming that the current value of the wire is zero, the
Only the current value information of the wire is transmitted, and the
At least one of the disconnected disconnector and the other end of the disconnector
Current value with the current value of the transmission line at the other end being open as zero
Since the information is received , it is possible to determine the cutoff section even if an accident occurs between the current transformer and the disconnector of the π-shaped branch terminal .

[0019]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, together with an application object. In FIG.
The same reference numerals denote the same elements. Here, a detailed configuration of the current differential relay device 31 is shown, and a new function is added thereto.

That is, the current differential relay device 31 includes input converters 1 and 2, filters 3A and 3B, A / D converters 4A and 4B,
Digital operation processing unit 5 and optical interface 6
And Of these, the secondary circuit of the current transformer 30A is connected to the primary side of the input converter 1, and the secondary side of the input converter 1 is connected to the input terminal of the AD converter 4A via the filter 3A. I have. A current transformer 30 is connected to the primary side of the input converter 2.
The secondary circuit of B is connected, and the secondary side of the input converter 2 is connected to the input terminal of the A / D converter 4B via the filter 3B. The output terminals of the A / D converters 4A and 4B are connected to a digital processing unit 5 and an optical interface 6. The digital arithmetic processing unit 5 includes disconnectors 33A,
Disconnector auxiliary contacts 34A and 34B for detecting the state of 33B are also connected. On the other hand, the digital arithmetic processing unit 5
The current value of the transmission line when the disconnector at
The disconnector at its own end obtains the current value information of the closed transmission line.
Transmission selection means 51 for transmitting the signal as it is,
A reception processing means 52 is provided for receiving the current value information with the current value of the electric wire being zero and outputting the open command of the breaker at its own end . The transmission selection means 51 is provided only in the current differential relay device provided corresponding to the π-type branch terminal,
The reception processing means 52 is provided in each of the current differential relay devices provided corresponding to each terminal.

The operation of the embodiment constructed as described above will be described below.

First, the current transformer 30 at the C terminal of the π-shaped branch
The secondary circuit current of A is converted by the input converter 1 to a voltage suitable for processing. The output of the input converter 1 is digitized by an A / D converter 4A after harmonic components are removed by a filter 3A, and is applied to a digital operation processing unit 5 and an optical interface 6. Similarly, the secondary circuit current of current transformer 30B is converted by input converter 2 to a voltage suitable for processing. The output of the input converter 2 is digitized by an A / D converter 4B after harmonic components are removed by a filter 3B and applied to a digital processing unit 5 and an optical interface 6.

Further, in order to determine an interruption section, a disconnector
Disconnector auxiliary contacts 34A and 34B that respond to opening and closing of 33A and 33B
Is also taken into the digital processing unit 5.

Here, the digital arithmetic processing unit 5 transmits the open / close information of the disconnector and the current value information of the line on which the disconnector is closed to the current differential relay device at the other end, respectively. Receive similar information from the current differential relay device.

Next, the current differential relay device 31 discriminates between an accident section and a cutoff section based on current value information of all terminals and disconnection switch opening / closing information, and sends the discrimination result to the other current differential relay device. In addition to the transmission, the same determination result is received from the current differential relay device at the other end.

The transmission selection means 51 constituting the digital arithmetic processing unit 5 is configured to output, from the two sets of current value information obtained by the current transformers 30A and 30B, only the current value information on the side where the disconnector is closed to the other end. Send. Also, the reception processing means 52 receives the current value of the current value information of the other terminal while the disconnecting switch is open, and receives the current value as zero .

FIG. 2 is a flowchart showing an example of the processing procedure of the digital operation processing unit 5 corresponding to the transmission selection means 51. In this case, it is determined in step (hereinafter, step is abbreviated as S) 10 whether or not the disconnector 33A is closed, and if it is closed, it is determined in S11 whether or not the disconnector 33B is closed. I do. If the disconnector 33B is not closed, only the secondary circuit current information of the current transformer 30A is transmitted in S12. When the disconnecting switch 33B is also closed, the added value information of the secondary circuit currents of both the disconnecting switches 33A and 33B is transmitted in S13. On the other hand, even if it is determined in S10 that the disconnector 33A is not closed, it is determined in S11 whether the disconnector 33B is closed. If the disconnector 33B is closed, only the secondary circuit current information of the current transformer 30B is transmitted in S14.
If the disconnecting switch 33B is not closed, the current is set to zero in S15 and the information is transmitted.

FIG. 3 shows an example of the processing procedure of the digital processing unit corresponding to the reception processing means 52, particularly showing a case where the current differential relay device 11 of the A terminal receives the current value information of the C terminal. Here, in S20, it is determined whether or not the disconnector 33A is closed. When the disconnector is closed, it is determined in S21 that the current information of the C terminal is introduced, and the process of outputting the open command of the own circuit breaker is executed. On the other hand, when the circuit is not closed, it is determined in step S22 that the current value information of the C terminal is not introduced (the current value of the current value information is zero), and the process of outputting a command to open the circuit breaker at its own end is executed.

FIG. 4 shows an example of the processing procedure of the digital operation processing unit corresponding to the reception processing means 52, and particularly shows a case where the current differential relay device 11 of the A terminal receives the current value information of the B terminal. That is, it is determined whether or not the disconnector 33A is closed in S30, and if it is closed, the disconnector 33B is determined in S31.
Is determined to be closed, and if it is closed, processing is performed in S32 assuming that the current value information of the B terminal is introduced. Young
If one of the disconnectors 33A and 33B is not closed, the process proceeds to S33 assuming that there is no current value information from the B terminal. This is seen from terminal A,
If either one of the disconnectors 33A and 33B provided between the terminal and the terminal is open, even if the current value information of the terminal B is received, the current value is processed as zero.

[0030] By the above process, for example, on the condition that the breaker 33A is opened, an accident occurs at f ₃ points in FIG. 5, the current differential relay device 11 of both the C terminal and the B terminal Assuming that the current value information has not been introduced to the information, it executes the output processing of the open command of its own circuit breaker, so it is necessary to reliably detect accidents that could not be determined as blind spot accidents in the past. Can be.

Although the above embodiment has been described with reference to a three-terminal transmission line including only one π-shaped branch path, the present invention is not limited to this.
Obviously, the present invention can be applied to a multi-terminal transmission line including two or more terminal terminals.

[0032]

As apparent from the above description, the present invention
According to Ming, the disconnector at its own end will change the current value of the open transmission line.
The current value of the closed transmission line is
Information is transmitted as it is, and the disconnection
One least the road device and the other end of the disconnector is Ah in open circuit
The current value of the transmission line at the other end is set to zero and the current value information is received.
This makes it possible to determine the interruption section even if an accident occurs between the current transformer and disconnector of the π-type branch terminal.
Become.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention together with an application target.

FIG. 2 is a flowchart illustrating a processing procedure of main elements according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure of main elements according to the embodiment of the present invention.

FIG. 4 is a flowchart illustrating a processing procedure of main elements according to the embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional protection relay device together with an application target.

FIG. 6 is a block diagram showing a configuration of another conventional protection relay device together with an application target.

[Explanation of symbols]

 Reference Signs List 5 digital arithmetic processing unit 10 current transformer 11 current differential relay device 13 disconnector 15 circuit breaker 20 current transformer 21 current differential relay device 23 disconnector 25 circuit breaker 30A current transformer 20B current transformer 31 current differential relay Device 33A Disconnector 33B Disconnector 35 Circuit breaker 51 Transmission selection means 52 Reception processing means

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Kazuo Ueno 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation (56) References JP-A-58-108920 (JP, A) JP-A-2- 262836 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02H 3/28 H02H 7/26

Claims (1)

(57) [Claims] 1. A multi-terminal transmission line including a π-type branch terminal.
Provided at the branch terminal for receiving the current value information of the own end and the switching information of the disconnector, transmitting the information to the other end, and receiving the current value information of the other end and the opening / closing information of the disconnector. Based on the current value information of the own end and the other end and the disconnection switch opening / closing information, the fault section discrimination between all terminals and the cutoff section
Make a decision and open the circuit breaker at the end according to the result of this decision.
In a digital type current differential protection relay device, the current value of the open transmission line is set to zero by the disconnector at its own end.
Transmission selection means for transmitting the current value information of the closed transmission line at the own end disconnector as it is, and reception processing for receiving the current value information by setting the current value of the other end transmission line at which the disconnector is open to zero Means, and a digital type current differential protection relay device comprising: