JPS6364504A - Control circuit for enclosed switchboard - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a closed switchboard having circuit breaker unit test and full sequence test functions.

[Conventional technology]

The conventional device, as described in Japanese Patent Application Laid-open No. 59-6705, was composed of two switches: a circuit breaker single operation switch and a unit test full sequence changeover switch. However, because it is operated by two switches,
There was a lack of consideration for unifying operability, effective use of installation space, etc.

[Problem that the invention seeks to solve]

In the conventional single circuit breaker and full sequence technology, this function is used only during test runs and periodic inspections, and the operability is as simple as possible, the number of control devices is small, and the circuit configuration is simple. Although it is hoped that this will happen, this point has not been taken into account.

There was a problem in that it was not possible to reduce the space for installing equipment on a closed switchboard.

The object of the present invention is to provide a simplified circuit breaker unit and
Provides full sequence functionality.

[Means for solving problems]

The above object is achieved by replacing the conventional changeover switch and operation switch with a manually connected twist type automatic return changeover switch and configuring a circuit.

[Effect]

The present invention relates to improvements in control circuits for switchboards. Generally, when operating a closed switchboard during a trial run or periodic inspection at a power plant, substation, etc., after inspecting the circuit breaker, a so-called unit test is performed to check the operation of the circuit breaker itself. A test cabinet equipped with an operation switch that connects the secondary control plug and the primary control movable plug on the circuit breaker side is used to electrically conduct the closing and disconnection tests of the fixed contacts and movable contacts located inside the circuit breaker. to be done. After the unit test has been completed, the circuit breaker is inserted into the switchboard and a full sequence test is performed as a system. In the full sequence test, with the circuit breaker set in the test position, the circuit breaker is inserted into the switchboard or the central control. By opening and closing the operation switch installed in the room to turn on and off the fixed contact and movable contact, it is tested whether the circuit breaker can function normally. Thus, the circuit breaker is inserted into the switchboard to perform its function.

[Example] In the conventional technology, unit tests and full sequence tests can be performed inside the switchboard, and unit tests and full sequence tests cannot be performed except in the test position, so that it is possible to carry out a test for improvement in the operating position. Since the secondary fixed disconnect section and the main contact are connected to the switch, for example, the changeover switch and unit test operation inside the closed switchboard should be done in order to prevent electrical shock to workers who are performing maintenance and inspection on the load. By configuring the circuit using switches, he achieved his goal of improving.

However, this function is used during plant trial runs or periodic inspections, and is not necessary during operation. Therefore, it has been desired to have simpler operability, a smaller number of control parts, and a simpler circuit configuration.

According to this embodiment, even if a single unit or full sequence test is performed in the operating position, maintenance personnel will not suffer an electric shock accident.

An embodiment of the present invention will be described below with reference to the closed power distribution g12 shown in FIGS. 1 to 4.

The switchboard 2 is provided with a partition plate 3 therein, and a primary fixed disconnection section 4 is attached to the partition plate 3. One primary fixed disconnection section 4 is connected to the load side and power supply side conductors 5.6. The current transformer 7 is arranged on the load side conductor 5. The power supply side conductor S is a power supply bus bar 9 supported by a support insulator 8 attached to the partition wall 3.
is connected to. The primary fixed disconnect section 4 on the other side is the circuit breaker 1
It is connected to the main contact 11 of No. 0.

When the circuit breaker 10 moves in and out of the switchboard, the main contactor 11 comes into contact with and separates from the primary fixed disconnecting section 4, thereby electrically opening and closing the circuit breaker 10. The position where the main contactor 11 and the primary fixed disconnector 4 are connected is generally referred to as the operating position 12. - The position where the main contactor 11 is separated from the next fixed disconnection section 4 is referred to as the test position 13.

A limit switch 14 is provided on the floor surface 2A at the operating position 12, and the limit switch 14 is pressed by the circuit breaker 10 at the operating position 12 and is closed. When the circuit breaker 10 moves to the test position 13, the pressure on the limit switch 14 is removed and opens.A secondary control fixing plug 15A is installed on the side of the switchboard at the operating position fi12 and the test position 13, as shown in FIG.
By attaching the secondary control fixed plug to the secondary control movable plug 15B attached to the circuit breaker 10 and separating it, a unit test and a full sequence test, which will be described later, are performed.
It is connected to the control circuit 16. As shown in FIGS. 1 and 2, the control circuit 16 that controls the closing and disconnecting of the circuit breaker 10 includes a closing test circuit 17 between the (+) side DC power supply P and the (-) side DC power supply N. The draw test circuit 18, input port v&19, and tripping circuit 2o are connected in parallel.

The input test circuit 17 and the draw test circuit 18 are (+)
It is connected in parallel between the sidecar current @p and the secondary control plug 15A. Input test episode '3I! r17 and the draw test circuit 18 include a closing limit switch 14A and a draw test limit switch 14A' that operate in the same way when the limit switch 14 is closed, and a closing test switch 14B and a draw test limit switch 14A' that operate in the opposite direction to these limit switches. The tripping test switch 14B' is connected in parallel. The twist type changeover switch 21 is the closing test switch 14
B and the secondary control movable plug 15A, the contact 2l-21B is normally closed, 2l-21A is closed when twisted to the input side, and when the operation handle 25 is released, the 2l-2
The above-described test is performed by switching between the unit test contact 21A and the full sequence contact 21B using an automatic return switch that returns to the 1B closed state.

Full sequence contact 21B is the closing limit switch 1
4A and the second input/draw operation switch 23. The second closing and tripping operation switch 23 is connected between the closing limit switch 14A and the secondary control fixing plug 15A, and is left in the Japanese and British control rooms. The trip changeover switch 24 is installed between the trip test switch 14B' and the secondary control fixing plug 15A, and has contacts 24-
24B is normally closed, 24-24A is tripped and closed when twisted, and when the operation handle is released, it automatically returns to the closed state of 24-24B, unit test contact 24A and full sequence contact 24.
It switches between B and B, and operates in the opposite way to the closing switch.

The tripping full sequence contact 24B is connected between the tripping limit switch 14A' and the second tripping operation switch 26. The second tripping operation switch 26 operates in the opposite direction to the second closing operation switch 23. One end of the second trip operation switch 26 is connected to the secondary control fixing plug 15A.

Secondary control fixed plug 15A connected to the input test circuit side and the draw test circuit side and the (-) measuring current current gN.
A secondary movable plug 15B is connected between the secondary control movable plugs, and a closing circuit 19 and a tripping circuit 20 are connected in parallel between the secondary control movable plugs.

The closing circuit 19 connects a first closing switch 27A and a closing relay 28 in series, and a second closing switch 27B.
The free tripping relay 29 is connected in parallel to the first closing switch 27A and the closing relay 28. The limit switch 30 is connected in parallel to the second closing switch 27B. The first closing switch 27A and the second closing switch 27B have the following relationship. That is, the limit switch 30
is closed, the free trip relay 29 is energized, the first closing switch 27A is opened, and the second closing switch 27B is closed to form a self-holding circuit. When the closing relay 28 is energized, the A contact 28A of the closing relay 28 is closed and the closing coil 31 is energized, so that the circuit breaker 10 moves a movable contact (not shown) and contacts a fixed contact.

The tripping circuit 20 is connected in parallel to the closing coil 31, and is configured by connecting a tripping switch 32 and a tripping coil 33 in series. When the tripping coil 33 is energized, the movable contact in the circuit breaker separates from the fixed contact.

Next, the operation of the control circuit 16 will be explained.

1) When the circuit breaker 1o is in the operating position 12, the main contactor 1
1 is connected to the primary fixed disconnection section 4, and the secondary control movable plug 15B is connected to the secondary control fixed plug 15A. On the other hand, since the circuit breaker 10 is pressing the limit switch 14 in the operating position 12, the limit switch 14 is closed.

Therefore, the closing limit switch 14 shown in FIG. 2(a)
A and trip limit switch 14A' are closed, but closing test switch 14B and trip test switch 14B' are open.

If the second closing operation switch 23 is twisted in this state, the closing circuit 17 is energized, so the circuit breaker 10 is closed.

To shut off the circuit breaker 10, by twisting the second tripping operation switch 26, the second closing operation switch 23 opens and the second tripping operation switch 26 closes, so that the tripping circuit 20 is closed. is excited and interrupts the circuit breaker 10.

2) When the circuit breaker 10 is in the test position 13, when performing a unit test, the circuit breaker 10 is moved from the operating position = 12 to the test position 13, and the main contactor 11 is placed in the primary fixed disconnect section 4.
As a result, the limit switch 14 is released from the pressing force of the circuit breaker 10 and opens. Then, the closing and tripping limit switches 14A, 14A shown in FIG.
' is opened, and the closing test switch 14B and the tripping test switch 14B' are closed. In this state, if the changeover switch 21 is turned to the 24A test input side, the closing circuit 17 is established and the circuit breaker 10 is closed. The circuit breaker 10 in the closing state is connected to the closing trip switch changeover switch 24.
When twisted to the test open side, the tripping circuit 18 is energized and the circuit breaker 10 is cut off.

When performing a full sequence test, since the circuit breaker 0 is connected to the test position 13, the operation/full sequence contact 21B is normally closed, so when the second closing operation switch 23 is closed, the closing circuit 19 is energized. Then, the circuit breaker 10 is turned on. When the circuit breaker 10 is to be disconnected, if the second tripping operation switch 26 is closed, the same operation as described above is performed and the circuit breaker is disconnected.

In this way, according to the control circuit 16 of the present invention, the circuit breaker 10
When reaches the test position 13, the limit switch is released, so the first closing and tripping operation switches 14A, 14A
' Close the first closing and tripping test switch 14.
Close B, 14B'.

Therefore, even if the changeover switch 21 is operated at the test position 13, no current flows, so that a unit test or a full sequence test can be performed. Also, when the circuit breaker 10 is in the test position 13, the second closing operation switch 23 is closed from the central control room, the circuit breaker 10 is closed, and current is supplied to the load side to operate the pump, for example. When a power equipment is being cooled, even if an on-site worker accidentally closes the closing switch 24, the circuit breaker 1o will not be shut off and will be able to supply current and load. Contrary to this, when a worker is maintaining or inspecting the pump on the load side with the second closing operation switch 26 closed and the circuit breaker 10 cut off, the closing operation switch 21 is Even if the door is closed, no current flows to the load side, so there is no risk of electric shock to the worker.

As described above, according to the present invention, even if the changeover switch 21 is accidentally operated in the operating position, the circuit breaker 10 cannot be closed or tripped, so it is safe. In addition, the changeover switch 21 has automatic communication plugs 4'Al41B...46B and is removable, so during normal operation, as shown in Figure 2, unused circuits are deleted, so the circuit during operation is simple. be converted into Further, if the circuit breaker 10 is in the operating position 12, the changeover switch 21 can be reliably operated in any state, that is, it is in a standby state. Therefore, when used for a load such as standby or emergency standby, it can be operated reliably.

The present invention provides a circuit in which the above-mentioned characteristics can be reduced to more N elements.

FIG. 4(a) shows the front area of the changeover switch 21 used in the present invention, with the breaker 19 in the test position and the handle 25 twisted in the (b) direction, and the contacts 21 to 24A closed. Pull out 19. Fig. 3 (b '') shows a developed view of this switch. If you twist the changeover switch 214 (b), 21 to 21A will close, and if you twist it to the side (a), 24 to 24 will close.
is closed and the handle 25 is not operated, 21~
21B and 24 to 24B are closed.

By using this switch 21, only one switch is required instead of two switches, which reduces the installation space for control equipment on the switchboard, and also simplifies the circuit because it can be removed during operation. It can contribute to improving reliability.

[Brief explanation of drawings]

1 and 2 are control circuit diagrams of a closed switchboard according to an embodiment of the present invention, FIG. 3(a) is a side sectional view of the closed switchboard, and FIG. FIG. 4, which is a side sectional view when viewed from the right side, shows a side view w4 (a), a front view (b), and a developed view of the contacts (c) of the changeover switch. 2...Switching board, 4...Primary fixed disconnection section, 10...
Circuit breaker, 11... Main contactor, 12... Operating position, 1
3...Test position, 14...Limit switch, 14A
and 14A'... Closing and tripping limit switch, 14B and 14B'... Closing and test switch, 19... Closing circuit, 20... Tripping circuit, 21.
・・Manual connection type automatic return changeover switch, 23 and 26
...Second closing and tripping operation switch.

Claims (1)

[Scope of Claims] 1. A closing circuit that closes the circuit breaker, a tripping circuit that disconnects the circuit breaker connected in parallel with the closing circuit, and a closing circuit that is connected in series with the closing circuit and the tripping circuit, respectively. and an external switch connected to a DC power source, the parallel connection with the closing switch and the tripping switch that operate when the circuit breaker provided between the closing and tripping switch and the DC power supply on one side comes to the test position. A closing test switch and a tripping test switch that become inoperable when the closing switch and the tripping switch operate, and a closing test switch and a tripping test switch provided between the closing test switch and the tripping test switch, and the closing circuit and the tripping circuit. What is claimed is: 1. A control circuit for a closed switchboard comprising an automatic connection type closing/trapping full sequence changeover switch that switches between a closing unit test, a closing full sequence test, and a tripping unit test and a tripping full sequence test.