JPH0740280Y2 - 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 a motor control circuit for a spring operating mechanism in a power circuit breaker, which is provided with a dynamic braking circuit attached to an armature circuit and a field circuit of a DC motor for closing spring energy storage. The electric motor is stopped immediately after the completion of the spring energy storage so that the energy storage can be smoothly performed.

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 closing hook, a closing electromagnet, a toggle link, a main lever, a connecting ring, etc. It The closing spring is connected to the eccentric cam, and is stored by the rotational force of the spring energy storage motor transmitted to the rotating shaft of the eccentric cam via gears, chains, reduction gears, etc. At a position beyond the dead point, the closing hook engages with the roller attached to the eccentric cam, and the state is maintained. This energy storage operation is performed immediately after the closing of the circuit (after the closing operation).

D. Problems to be solved by the invention With the spring operation mechanism having such a configuration, the time from the dead point to the joining hook and the roller is very short, and it is necessary to stop the electric motor immediately after the joining hook and the roller are joined. If you do not stop within about 10 rotations of the rotating shaft of the electric motor, the rotating force of the electric motor will be applied to the joint between the closing hook and the roller as an excessive force via the reduction gear,
The roller may be destroyed.

An object of the present invention is to provide a closing spring energy storage motor control circuit for a power circuit breaker that can appropriately stop the spring energy storage motor at a required time.

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,
A magnetic field control electromagnetic contactor whose opening and closing operations are controlled by the limit switch, an armature control electromagnetic contactor whose opening and closing operation is controlled by the limit switch and the field control electromagnetic contactor, and contacts of these electromagnetic contactors. And a dynamic braking circuit attached to the armature circuit and the field circuit of the DC motor for energizing the closing spring, the two electromagnetic contactors being operated by the limit switch when the energization of the closing spring is completed. Is driven to cut off the energization of the armature and the field circuit of the electric motor, and at the same time, the dynamic braking circuit is activated.

F. Action When the closing spring is instantly released by the closing operation and the limit switch is closed, the electromagnetic contactor for field control and the electromagnetic contactor for armature control are energized, and the field winding is connected via its a contact. And a current flows through the armature winding. That is, the electric motor is started. The turning force of the electric motor causes the closing spring to store energy.

When the spring energy storage is completed, the limit switch operates to deactivate both contactors, and the contacts form a dynamic braking circuit in the electric motor section to perform dynamic braking. As a result, the electric motor suddenly stops, and the energy is smoothly retained.

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 1A is an armature winding of a closing spring energy storage motor (DC motor), 1F is a field winding of the same motor, 2 is a 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 breaker and the completion of energy storage, which is turned off when the energy storage is completed. Reference numeral 4 denotes an electromagnetic contactor for field control whose opening / closing operation is controlled by the limit switch 3. Reference numeral 5 denotes an electromagnetic contactor for armature control whose opening / closing operation is controlled by the limit switch 3 and the electromagnetic contactor 4 for field control.

One end of the coil 4c of the electromagnetic contactor 4 is connected to the power source end P, the other end is connected to one end of the coil 5c of the electromagnetic contactor 5, and is connected to the power source end N via the limit switch 3. ing. The other end of the coil 5c of the electromagnetic contactor 5 is connected to one end of the coil 4c, that is, the power supply end P via the make contact (a contact) 4-1a of the electromagnetic contactor 4.

On the other hand, the armature winding 1A is the a-contact 5 of the electromagnetic contactor 5.
-1a and the circuit breaker 2 for wiring, and are connected between the power source terminals P and N. A break contact (b contact) 5-1b of the electromagnetic contactor 5 is connected in parallel to the armature winding 1A, and a series circuit of the contact 4-1b of the electromagnetic contactor 4 and the field winding 1F. Are connected in parallel. A surge absorber 6 is connected in parallel to the field winding 1F, and a contact 4-
One end of the 1b side is connected to a connection point between the contact 5-1a and the wiring breaker 2 via an a contact 4-2a of the electromagnetic contactor 4. The contacts 4-1a, 4-1b, 5-1a, 5-1b are added to the armature circuit and field circuit of the closing spring DC motor.
Is constructed as described above and a dynamic braking circuit is attached.

Next, the operation will be described.

(A). Immediately after the closing operation When the closing operation is performed by the closing command, the closing spring is released and the limit switch 3 is turned on. As a result, the electromagnetic contactor 4 for controlling the field is energized, and the field winding 1F
A voltage is applied to. At the same time, the electromagnetic contactor 5 for controlling the armature is energized, its b contact 5-1b is opened and its a contact 5-1a is closed, and a voltage is applied to the armature winding 1A. That is, the closing spring energy storage motor is started, and the closing spring energy storage by the rotational force is started.

(B). When the closing spring energy storage is completed At the same time when the closing spring energy storage is completed, the limit switch 3
Turns off. As a result, both electromagnetic contactors 4 and 5 are deenergized, the a contacts 4-2a and 5-1a are opened, and the armature current and field current of the electric motor are cut off. At the same time, the b-contacts 4-1b and 5-1b are closed, and a short circuit is formed in the motor section to short-circuit both terminals of the armature winding 1A and field winding 1F. At this time, the electric motor operates as a generator, the generated torque is reversed, and braking is performed. That is, dynamic braking is performed, and the electric motor is suddenly stopped.

FIG. 2 shows changes in the armature current and the rotation speed of the motor shaft portion in the above-described operation. As is apparent from FIG. 2, the time required for stopping is significantly shortened as compared with the case where the braking circuit is not provided (change in rotational speed shown by the dotted line).

H. Effect of the Invention As described above, according to the present invention, since the dynamic braking circuit is provided in the electric motor part, the closing spring energy storage electric motor is appropriately stopped about two revolutions after the hook and the roller are joined. It is possible to prevent the roller from being destroyed. Further, since the field winding is always excited first when the electric motor is started, there is an advantage that the starting current can be suppressed.

[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 an operation explanatory view of the embodiment. 1A ... Armature winding of closing spring energy storage motor, 1F ... Field winding, 2 ... Circuit breaker, 3 ... Limit switch for detecting completion of closing spring energy storage, 4 ... Magnetic contactor for field control 5 ... Electromagnetic contactor for armature control, 4-1a, 4-2a and 5-1a ... a contact, 4-1b and 5-1b ... b contact.

Claims (1)

[Scope of utility model registration request] Claims: 1. A limit switch for detecting the release and energization completion of a closing spring of a spring operating mechanism in a power circuit breaker, an electromagnetic contactor for field control whose opening / closing operation is controlled by the limit switch, and the limit switch. An armature control electromagnetic contactor whose opening and closing operations are controlled by the field control electromagnetic contactor, and contacts of these electromagnetic contactors, which are attached to the armature circuit and the field circuit of the DC motor for closing spring accumulation. And a power generation braking circuit, which drives the two electromagnetic contactors by the response of the limit switch when the energy of the closing spring is completed to cut off the energization of the armature of the electric motor and the field circuit. A motor control circuit for closing spring energy storage of a power circuit breaker, characterized in that a power generation braking circuit is activated.