JPH05276648A - Wiring method of test terminal for bus protective relay - Google Patents

Abstract

PURPOSE:To eliminate nonprotective state at the time of testing one bus protective relay in a system where the bus is protected through duplex bus protective relays. CONSTITUTION:Short-circuiting test terminals 5A, 51A, 5B, 51B are employed for respective phases and the test terminals are interconnected such that a fault current flows to a bus protective relay 6B side upon occurrence of fault on the transmission line 21-23 side at the time of testing a bus protective relay 6A. Furthermore, each test terminal 51A for R, S, T phase of the bus protective relay 6A is connected with each test terminal 51B for S, T, N phase of the bus protective relay 6B thus preventing current transformers(CT) 31-33 from being brought into open state at the time of concurrent test of both bus protective relays 6A, 6B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for wiring a bus protection relay test terminal.

[0002]

2. Description of the Related Art A conventional example of this type is shown in FIG. In the figure, 1 is a busbar, 21, 22, and 23 are power transmission lines, and 31 and 3.
Reference numerals 2 and 33 are current transformers (CT) provided on the power transmission line, 4 is a test plug, 5 is a test terminal, and 6A and 6B are busbar protection relays. That is, the busbar protection relays 6A and 6B are C
The current from T is monitored, and the currents flowing through the line L are zero because the three-phase currents are balanced with each other in a normal state, but if a failure occurs at the point P for some reason, the three-phase currents are unbalanced. Therefore, the line L has a fault current IF.
Flows. This fault current I is applied to the busbar protection relays 6A and 6B.
In response to F, a predetermined protection operation is performed. The busbar protection relays 6A and 6B are duplicated here, so that reliability is ensured so that even if one of them fails, the other one can perform a protective operation.

[0003]

SUMMARY OF THE INVENTION Busbar protection relay 6A,
Although 6B is duplicated, its protection is disabled if both of them fail, so the test is performed as necessary. For example, when testing the busbar protection relay 6A, the test plug 4 is inserted into the test terminal 5, and the busbar side short-circuits the three phases of R, S, and T and the neutral wire N at once, thereby reducing the CT. The bus bar protection relay 6A side is configured so that a test can be performed by applying a pseudo test signal from the test terminal 5 while preventing the open state. Therefore, as the test terminal, a collective short-circuit terminal is used here. However, in this way, even if a failure occurs on the power transmission line side during the test of the busbar protection relay 6A, the busbar side is short-circuited by the test plug 4, so a failure current is given to the busbar protection relay 6B side. No
Therefore, there is a problem that protection cannot be performed. It should be noted that this relationship is the same when a failure occurs in the busbar protection relay 6B during the test. Therefore,
The subject of this invention is when the busbar protection relay is duplicated,
The aim is to avoid the inconvenience of being unable to protect the other side during the test.

[0004]

In order to solve such a problem, according to the present invention, the R, S, T lines of the transmission line, which is composed of the R, S, T lines and the neutral line N and is connected to the busbar, are connected. While providing current transformers that detect the flowing current respectively, the protection relay that protects the bus based on the sum of the currents detected by each current transformer is duplicated. During the test, the bus terminals are short-circuited by the test terminals. When the test is performed by applying a test signal from this terminal with the protection relay side in an open state, a test terminal short-circuited for each phase is used as the test terminal and R, S, T of one protection relay are used. By connecting each test terminal of one phase to the S, T, and N phases of the test terminal of the other protection relay, the bus bar can be protected by the other protection relay during the test of one protection relay, and both The current transformer during the test It is characterized in that it does not in the open state.

[0005]

[Function] A test terminal which is short-circuited for each phase is used as a test terminal, and each of the R, S, and T phase test terminals of one protection relay is connected to the S, T, and N phases of the other protection relay. By connecting each of them, the bus bar can be protected by the other protection relay during the test of one protection relay, and further, the current transformer is not opened during the test of both protection relays.

[0006]

1 is a block diagram showing an embodiment of the present invention, FIG.
FIG. 3 is an explanatory diagram for explaining current paths. In FIG. 1, 5A, 51A, 5B and 51B indicate test terminals that can be short-circuited for each phase, and 41 indicates a test plug for the busbar protection relay 6B. That is, this point is different from FIG. 3, and other points are the same as in FIG. Although the test terminals 5A, 51A, 5B, and 51B are shown only for the R phase, it goes without saying that the same applies to the S, T, and N phases. Here, considering the case of testing the busbar protection relay 6A, in this case, the terminals 5A and 51A are connected by inserting the test plug 4, and R
The line is open at the point of terminal 51A. This is another S
The same applies to the lines, T lines, and N lines. Therefore, even if a failure occurs during the test of the busbar protection relay 6A, the failure current IF is as shown by the arrow in FIG.
As a result, the busbar protection is possible.
If a failure occurs during the test of the busbar protection relay 6B, the fault current IF is given to the busbar protection relay 6A, so that the busbar protection can be performed in the same manner.

However, in this way, if tests are conducted simultaneously on the busbar protection relays 6A and 6B, the CT shown in FIG.
Since 31 to 33 are in an open state and inconvenience occurs, here, the R-phase test terminal 51A on the busbar protection relay 6A side is used as the S-phase test terminal 51B on the busbar protection relay 6B side, and the S on the busbar protection relay 6A side is used. The phase test terminal 51A is connected to the T-phase test terminal 51B on the busbar protection relay 6B side, and the T-phase test terminal 51A on the busbar protection relay 6A side is connected to the N-phase test terminal 51B on the busbar protection relay 6B side. By doing so, a current path as shown by an arrow J in FIG. 2 is formed so that the CT is not opened.
In this way, test terminals that can be short-circuited for each phase are used, and the connection method of each terminal is set as described above, so that the protection of the busbar is protected by the other protection relay during the test of one protection relay. In addition to making it possible, it is possible not to open the current transformer when testing both protection relays.

[0008]

According to the present invention, a test terminal that is short-circuited for each phase is used as a test terminal, and the R, S, and T phase test terminals of one protection relay are connected to the test terminals of the other protection relay. Since the S, T, and N phases are connected to each other, the bus bar can be protected with the other protection relay during the test of one protection relay, and the CT can be used during both tests.
Can be prevented from being released.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a current path of FIG.

FIG. 3 is a schematic diagram showing a conventional example.

[Explanation of symbols]

1 ... Bus lines 21, 22, 23 ... Power transmission lines 31, 32, 3
3 ... Current transformer (CT), 4, 41 ... Test plug, 5, 5
A, 51A, 51B ... Test terminal, 6A, 6B ... Busbar protection relay.

Claims (1)

[Claims] 1. A current transformer is provided for detecting currents respectively flowing in R, S, T lines of a transmission line composed of R, S, T lines and a neutral line N and connected to a bus bar, while each current transformer is provided. The protection relay that protects the bus based on the sum of the currents detected by is duplicated. During the test, the test terminal shorts the bus side, the protection relay side is opened, and the test signal is applied from this terminal. In carrying out the test, a test terminal short-circuited for each phase is used as the test terminal, and the R, S, and T phase test terminals of one protection relay are connected to the test terminals of the other protection relay. , And N phase respectively, the bus bar can be protected by the other protection relay during the test of one protection relay, and the current transformer is not released during the both tests. Bus protection relay test terminal Wiring method.