JPH11126547A - Apparatus for suppressing short circuit current - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress heat generation out of a current limitting resistor by preventing surge current from flowing in a load circuit. SOLUTION: In this short-circuit current-suppressing apparatus comprising a circuit constituted of a commutation unit 3 and a current-limitting resistor 4 connected to each other in parallel and connected in series with a circuit to which a separating switchgear 2 is connected, a connecting lever 6 whose one end is attached to an operational axis 2a of the separating switchgear 2 and whose the other end has a relatively long hole 6a engaged with a pin 3b installed in an operational axis 3a of the commutator 3 and an operational handle 5 attached to the operation shaft 2a of the separating switchgear 2 are installed to transmit the movement of the operation shaft 2 of the separating switchgear 2 with delay to the operation shaft 3a of the commutation unit 3. Consequently, no surge electric current flows to a load circuit and heat generation out of the current-limitting resistor is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short-circuit current suppressing device.

[0002]

2. Description of the Related Art A conventional short-circuit current suppressing device is configured as shown in FIG. In the figure, reference numeral 20 denotes a short-circuit current suppressing device, in which a circuit in which a disconnecting switch 21 is connected and a circuit in which a commutator 22 and a current limiting resistor 23 are connected in parallel are connected in series. Reference numeral 24 denotes an operation handle for opening and closing the disconnecting switch 21, and reference numeral 25 denotes an operation handle for operating the commutator 22. Reference numeral 26 denotes an operation mechanism including a toggle spring mechanism and the like, which is configured to open and close the disconnecting switch 21 by operating the operation handle 24. 27
Is an operation mechanism including a toggle spring mechanism and the like, and is configured to open and close the commutator 22 by operating the operation handle 25. Reference numeral 28 denotes a terminal connected to the disconnecting switch 21, and the terminal 28 is connected to a power source (not shown). Reference numeral 29 denotes a load terminal connected to a circuit connected to the commutator 22. A load circuit (not shown) is connected to the load terminal 29, and a plurality of electric devices are connected to the load circuit. When the operating handle 24 is operated in the direction of the arrow D, the short-circuit current suppressing device 20 thus configured
To close the disconnecting switch 21. When the disconnecting switch 21 is closed, the current flows through the disconnecting switch 21, the current limiting resistor 23, and the plurality of electric devices of the load circuit connected to the load terminal 27. When the operation handle 25 of the commutator 22 is operated in the direction of the arrow C after a certain period of time after the disconnecting switch 21 is closed, the commutator 22 is closed by the operation mechanism 27. When the commutator 22 is closed,
The current flows from the disconnecting switch 21 to the commutator 22 and does not flow to the current limiting resistor 23. Therefore, a surge caused by closing the disconnecting switch 21 does not flow to a plurality of electric devices connected to the load circuit connected to the load terminal 27.

[0003]

However, in the conventional short-circuit current suppressing device, the disconnecting switch 21 is connected to the operating handle 2.
4, the commutator 22 is closed by operating the operation handle 25 of the commutator 22 after a certain time after the disconnector switch 21 is closed, and after the disconnector switch 21 is closed, If the time until the commutator 22 closes is long, the current flowing through the current limiting resistor 23 causes the current limiting resistor 23 to generate heat, and the short-circuit current suppressing device is adversely affected by the heat. Therefore, immediately after the disconnecting switch 21 is closed, the commutator 22
When the commutator 22 is closed by operating the operation handle 25, the surge current caused by the switching by the disconnecting switch 21 flows from the load terminal 27 to the electric equipment of the load circuit, and the insulation of the electric equipment is damaged by the surge current. Was. Therefore,
The present invention prevents a surge current from flowing through a load circuit,
It is intended to suppress heat generation from the current limiting resistor.

[0004]

In order to solve the above problems, the present invention provides a short circuit in which a circuit in which a commutator and a current limiting resistor are connected in parallel is connected in series to a circuit in which a disconnecting switch is connected. In the current suppressing device, a connecting lever having one end attached to the operating shaft of the disconnecting switch and a long hole provided at the other end engaged with a pin provided on the operating shaft of the commutator; and operation of the disconnecting switch. With an operation handle attached to the shaft,
The operation of the operating shaft of the disconnecting switch is transmitted to the operating shaft of the commutator with a delay.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a short-circuit current suppressing device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a short-circuit current suppressing device, in which a circuit in which a commutator 3 and a current limiting resistor 4 are connected in parallel is connected in series to a circuit to which a disconnecting switch 2 is connected, and a terminal 10 is connected to this circuit. A load circuit (not shown) connecting a plurality of electric devices is connected via the. 2a
Is the operating shaft of the disconnecting switch 2, 3a is the operating shaft of the commutator 3, 5 is the operating handle attached to the operating shaft 2a of the disconnecting switch 2, and 6 is one end fixed to the operating shaft 2a of the disconnecting switch 2. The connecting lever has a long hole 6a at the other end, and a pin 3 provided on the operation shaft 3a of the commutator 3 in the long hole 6a.
b is fitted. Reference numeral 7 denotes an operation mechanism including a toggle spring mechanism and the like, which is configured to open and close the disconnecting switch 2 by operating the operation handle 5. An operation mechanism 8 includes a toggle spring mechanism and the like, and is configured to open and close the commutator 3 by operating the connection lever 6. A terminal 9 is connected to a power supply (not shown). When the operation handle 5 of the disconnecting switch 2 of the short-circuit current suppressing device 1 thus configured is operated in the direction of arrow A, the operating mechanism 7 closes the switching contact of the disconnecting switch 2 and the connecting lever 6 moves the arrow B. Operating in the direction, the long hole 6a of the connecting lever 6 moves along the pin 3b of the operation shaft 3a of the commutator 3. The current flowing through the disconnecting switch 2 is a current limiting resistor 4
Flows through the load circuit connected to the terminal 10, and no surge current due to the closing of the disconnecting switch 2 flows. Further, when the operating handle 5 is operated, the connecting lever 6 is operated in conjunction with the rotation of the operating shaft 2 a of the disconnecting switch 2, and the elongated hole 6 a of the connecting lever 6 is moved to the pin 3 b of the operating shaft 3 a of the commutator 3. In this case, the operating mechanism 8 is operated by the connecting lever 6 to close the commutator 3. After closing the disconnecting switch 2 in this way, the commutator 3 is closed after a certain period of time, so that current flows through the commutator 3 without flowing to the current limiting resistor 4.
Therefore, since current does not flow through the current limiting resistor 4 for a long time, heat generation of the current limiting resistor 4 is suppressed.

[0006]

As described above, in the short-circuit current suppressing device according to the present invention, the commutator is closed after a certain period of time after the disconnecting switch is closed, so that a surge current does not flow in the load circuit and the current limiting resistance is reduced. Heat generation from the vessel can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a short-circuit current suppressing device according to the present invention.

FIG. 2 is a block diagram of a conventional short-circuit current suppressing device.

[Explanation of symbols]

1 short-circuit current suppression device, 2 disconnecting switch, 2a
Operating shaft, 3 commutator, 3a Operating shaft, 3b pin, 4 current limiting resistor, 5 operating handle, 6 connecting lever, 6a long hole, 7, 8 operating mechanism, 9, 1
0 terminal

Claims (1)

[Claims] 1. A short-circuit current suppressing device in which a circuit in which a commutator and a current limiting resistor are connected in parallel is connected in series to a circuit in which a disconnecting switch is connected, wherein one end is connected to an operating shaft of the disconnecting switch. A connection lever in which a long hole provided on the other end of the commutator is engaged with a pin provided on an operation shaft of the commutator; and an operation handle attached to the operation shaft of the disconnect switch, the disconnect opening and closing. The operation of the operating shaft of the commutator is transmitted to the operating shaft of the commutator with a delay.