JPH0740282Y2 - Closing spring for power circuit breaker Motor control circuit for energy storage - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a control circuit of an electric motor used for accumulating a spring of a spring operating mechanism in a power circuit breaker.

B. Outline of the Invention The present invention is for supplying DC power to two phases of an electric motor to a drive circuit of a three-phase induction motor for accumulating springs in an electric motor control circuit used for a spring operating mechanism of a power breaker. By providing the dynamic braking circuit with the rectifier circuit, the dynamic braking function stops the electric motor in an extremely short time, thereby preventing the roller from being broken by the rotating force of the electric motor and the deformation of the closing hook.

C. Conventional technology There is a spring operating mechanism as one of the operating mechanisms of the power circuit breaker, which is composed of a closing spring, a closing cam (eccentric cam), a hook, a closing electromagnet, a toggle link, a main lever, a connecting ring, etc. . A part thereof is shown in FIG.

In the figure, 21 is a toggle link, 22 is a closing hook, 23 is an eccentric cam, and 24 is a closing spring having one end connected to the eccentric cam 23. The closing spring 24 is stored in the rotating shaft of the eccentric cam 23 by a rotational force of a closing spring energy storage motor transmitted through a gear, a chain, a speed reducer, etc. Insertion hook at a position past the point
When the roller 22 attached to the eccentric cam 23 and the roller 22 are joined to each other, the energy storage state is maintained. This energy storing action is performed immediately after the completion of the closed circuit (after the closing operation).

D. Problem to be Solved by the Invention With the spring operation mechanism having such a configuration, the time from the dead point to the engagement of the closing hook 22 and the roller 25 is very short, and when the closing hook 22 and the roller 25 are engaged. It is necessary to stop the electric motor immediately, and the rotation speed of the electric motor's rotating shaft
If it does not stop within 10 rotations, the rotating force of the electric motor will be applied as an excessive force through the reduction gear to the engaging part of the closing hook 22 and the roller 25, and the roller 25 will be broken or the closing hook 22
May be deformed and the closing spring 24 may not be able to be held in the stored state.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a closing spring energy storage motor control circuit for a power circuit breaker that can properly stop the closing spring energy storage motor at a required point.

E. Means for Solving the Problems The present invention provides a limit switch for detecting the release of the closing spring of the spring operating mechanism of the power circuit breaker and the completion of energy storage,
Opening and closing operations are controlled by this limit switch, and the voltage of the operating magnetic power supply and the driving electromagnetic contactor whose contacts are inserted into the drive circuit of the three-phase induction motor for energizing the closing spring and the operating AC power supply are transformed to the required values. A transformer, a rectifier circuit connected to the output end of the transformer, and a braking electromagnetic contactor having contacts inserted between the DC output end of the rectifier circuit and the two-phase input end of the electric motor. Then, at the same time when the charging of the closing spring is completed, the limit switch is turned off, thereby deactivating the driving electromagnetic contactor and stopping the supply of the three-phase AC power to the three-phase induction motor. A braking control unit that controls the electromagnetic contactor for braking so that the DC output voltage of the rectifier circuit is applied to the two phases of the three-phase induction motor.

F. Action When the closing spring is released, the limit switch operates and the driving magnetic contactor is energized, and the three-phase induction motor starts. By this activation, the charging of the closing spring is started. At the same time, the braking control unit operates to prepare the energization of the braking electromagnetic contactor.

At the same time that the closing spring is fully energized, the limit switch is actuated, the driving electromagnetic contactor is deenergized, and the braking electromagnetic contactor is energized. As a result, DC power is supplied from the rectifier circuit to the two phases of the electric motor. That is, dynamic braking is performed and the electric motor is suddenly stopped. Dynamic braking is performed for an extremely short time, and then reset.

G. Embodiment Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a three-phase induction motor as a closing spring energy storage motor, and 2 are R, S, and T phases between the motor 1 and an AC power source. The circuit breaker for wiring 3 is a limit switch for detecting the release of the closing spring of the spring operating mechanism of the power circuit breaker and the completion of the accumulation of energy.
The limit switch 3 is turned off upon completion of energy storage. Reference numeral 4 denotes an electric motor driving electromagnetic contactor whose opening / closing operation is controlled by the limit switch 3. Reference numeral 5 denotes an electric motor braking electromagnetic contactor controlled by a braking control unit described later. The braking control unit includes an electromagnetic contactor 6 for electric motor braking control and a timer 7 for electric motor braking control. 8 is a rectifying bridge circuit, 9 is a primary side R, T of the load side of the circuit breaker 2 for wiring
It is a transformer in which the secondary side is connected between the AC input terminals of the rectifying bridge circuit 8 between the two phases.

The electric motor driving electromagnetic contactor 4 has its coil 4c connected between the control power source terminals P and N via the limit switch 3, and has an a contact (make contact) 4-1a for the three-phase induction motor 1 and wiring. The a-contact 4-2a is inserted in the R phase between the circuit breakers 2 and the T phase is inserted in the T phase.

The electric motor braking electromagnetic contactor 5 has one end of a coil 5c thereof through a series circuit of an a contact 6-1a of the braking control electromagnetic contactor 6 and a b contact 4-1b of the electric motor driving electromagnetic contactor 4. The power source end P and the other end of the timer 7 have a time contact 7-1b.
Connected to the power supply terminal N via the
-2a is connected between the R- and S-phase input ends of the three-phase induction motor 1 and the DC output end of the rectifying bridge circuit 8. Then, the b-contact 5-1b is inserted in the S-phase between the front three-phase induction motor 1 and the circuit breaker 2 for wiring.

The braking control electromagnetic contactor 6 has one end of a coil 6c at an a contact 4-3a of the driving contactor 4 and its own a contact 6
-2a is connected to the power source end P through a parallel circuit, and the other end of the coil 5c of the braking electromagnetic contactor 5 (the time contact 7
-1b side). Further, the timer 7 has its coil portion 7c connected to the a contact 5-3a of the braking electromagnetic contactor 5.
Is connected between the power supply terminals P and N via. The limit switch 3 is turned off when the closing spring is fully charged.

Next, the operation will be described.

Immediately after closing operation When a closing command is issued, the closing spring releases the force and limit switch 3 is turned on. When the limit switch 3 is turned on, the driving electromagnetic contactor 4 is energized, and its a contact 4-1a,
A three-phase induction motor for closing spring energy storage with closing of 4-2a 1
Is activated, and the charging of the closing spring is started. At the same time, the braking control electromagnetic contactor 6 is energized to be in a self-holding state.

b. Immediately after the closing spring energy storage is completed.
Turns off. Along with this, the driving electromagnetic contactor 4 is deenergized, and the braking electromagnetic contactor 5 is energized. By this operation, the supply of the 3-phase AC power to the 3-phase induction motor 1 is stopped, and the DC output voltage of the rectifying bridge circuit 8 is applied to the 2-phase instead. Therefore, a voltage is induced in the rotor, a rotor current flows, and power is consumed. That is, it becomes a dynamic braking action, and the three-phase induction motor 1 suddenly stops.

Further, the timer 7 is driven at the same time as the braking electromagnetic contactor 5 is energized, and after the set time (for example, 2 seconds), the time contact 7-1b.
Is opened and the braking electromagnetic contactor 5 and the braking control electromagnetic contactor 5 are deenergized. Then, the timer 7 is also turned off.

H. Effect of the Invention As described above, according to the present invention, the dynamic braking including the drive circuit of the three-phase induction motor for storing the closing spring and the rectifier circuit for applying the DC voltage to the two phases of the motor. Since the circuit is provided, it is possible to stop the electric motor after the engaging hook and the roller are engaged with each other by rotating the electric motor rotating shaft at about 2 to 4 times, and the roller is broken by the electric motor rotating force. It is possible to solve the problem that the closing hook is deformed and the energized state of the closing spring cannot be maintained.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a closing spring energy storage motor control circuit of a power circuit breaker according to the present invention, and FIG. 2 is a schematic configuration diagram showing a part of a spring operating mechanism. DESCRIPTION OF SYMBOLS 1 ... Three-phase induction motor for closing spring accumulation, 2 ... Wiring circuit breaker, 3 ... Limit switch for completion of closing spring accumulation, 4 ... Electromagnetic contactor for driving motor, 4-1a to 4-3a ... a contact , 4-
1b ... b contact, 5 ... electromagnetic contactor for braking, 5-1a to 5-3a ...
a contact, 5-1b ... b contact, 6 ... electromagnetic contactor for braking control,
6-1a and 6-2a ... a contact, 7 ... braking control timer,
7-1b ... time-definite contact, 8 ... rectifier bridge circuit, 9 ... transformer.

Claims (1)

[Scope of utility model registration request] 1. A limit switch for detecting the release of a closing spring of a spring operating mechanism of a power circuit breaker and the completion of energy storage, and an opening / closing operation is controlled by the limit switch.
A drive electromagnetic contactor whose contacts are inserted into the drive circuit of a three-phase induction motor for energizing the closing spring, a transformer for transforming the voltage of the operating AC power supply to a required value, and an output end of this transformer. The rectifier circuit connected to the rectifier circuit, the braking electromagnetic contactor having a contact inserted between the DC output end of the rectifier circuit and the two-phase input end of the electric motor, and the charging of the closing spring is completed. At the same time, the limit switch is turned off to deactivate the driving electromagnetic contactor to stop the supply of the three-phase AC power to the three-phase induction motor, and then the DC output voltage of the rectifier circuit is set to the three And a braking control unit that controls the braking electromagnetic contactor so as to be applied to two phases of the phase induction motor.