JPH0740281Y2 - 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 In the present invention, in the electric motor control circuit of the spring operating mechanism in the power breaker, the dynamic braking circuit is attached to the armature circuit and the field circuit of the closing spring energy storage DC motor.
The CR series circuit for surge absorption is connected in parallel to the limit switch for closing closing of the closing spring that controls the opening / closing operations of the electromagnetic contactor for armature control and the electromagnetic contactor for controlling the field, so that the motor immediately after the closing of the closing spring is completed. It is possible to make a smooth transition to the energy storage holding state by stopping the operation, and to surely continue to energize the electromagnetic contactor even when chattering the limit switch to maintain the control function. .

C. Conventional technology There is a spring operating mechanism as one of the operating mechanisms for power circuit breakers, 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 link, 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).

In the spring operation mechanism with such a structure, the time from the dead point to the joining of the closing hook and the roller is very short, and it is necessary to stop the electric motor immediately after the connecting of the closing hook and the roller. If you do not stop within about 10 rotations in number, the rotating force of the electric motor will be applied as an excessive force through the reducer to the joint between the closing hook and the roller,
The roller may be destroyed.

As a solution to this, an electric motor control circuit as shown in FIG. 2 has been devised. In the figure, 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 wiring breaker, and 3 is a spring operating mechanism of a power breaker. A limit switch for detecting the release of the spring and the completion of energy storage. It is turned off when the energy storage is completed. Four
Is an electromagnetic contactor for field control whose opening / closing operation is controlled by the limit switch 3, and 5 is an electromagnetic contactor for armature control whose opening / closing operation is controlled by the limit switch 3,
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. . 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 source end P via the make contact (a contact) 4-1a of the contactor 4.

On the other hand, the armature winding 1A is the a-contact 5 of the electromagnetic contactor 5.
-1a and the wiring breaker 2 are connected between the power source terminals P and N. The break contact (b contact) 5-1b of the electromagnetic contactor 5 is connected in parallel to the armature winding 1A, and the b contact 4-1b of the electromagnetic electromagnetic contactor 4 and the field winding 1F are connected in series. The circuits are connected in parallel. A surge absorber 6 is connected in parallel to the field winding 1F and contacts 4-1b are provided.
, One end of which is connected to the connection point between the contact 5-1a and the wiring breaker 2 via the a contact 4-2a of the contactor 4.

The above-mentioned electric motor control circuit operates as follows.

(A) Immediately after closing operation When the closing operation is performed by the closing command, the closing spring releases the limit switch 3 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 4,5 are deenergized, and their a contacts 4-2a, 5-1a are opened.
The armature current and field current of the electric motor are cut off. at the same time,
The b-contact 4-1b.5-1b is closed, and a short circuit is formed in the armature portion, and both ends of the armature winding 1A and the field winding 1F are short-circuited. 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.

In this way, it becomes possible to immediately stop the electric motor at a required point and smoothly shift to the spring-accumulated holding state.

D. Problem to be solved by the invention By the way, since the circuit breaker needs to operate at high speed, the operating energy inevitably increases, and an excessive impact force acts on the entire circuit breaker during operation. This becomes remarkable as the voltage increases.

For this reason, the control electric component is installed in consideration of vibration prevention and the like, but the limit switch 3 is used for the purpose of detecting the operating position (the point where the closing spring has accumulated energy), and therefore is firmly attached. In some cases, excessive impact force may cause chattering. If chattering occurs, the excitation of the electromagnetic contactors 4 and 5 will be intermittent, and the control function may be impaired by interrupting the current through the contacts.

An object of the present invention is to provide a closing spring energy storage motor control circuit for a power circuit breaker that can immediately stop the spring energy storage motor at a required point and prevent deterioration of control function due to chattering of a limit switch. To do.

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 surge connected in parallel with the limit switch via a contact point of the armature control electromagnetic contactor and a dynamic braking circuit attached to the armature circuit and field circuit of the DC motor for closing spring accumulation. The absorption CR series circuit is provided, and the contact of the armature control electromagnetic contactor is closed by the response of the limit switch when the closing spring is released to limit the surge absorption CR series circuit to the limit. The switch is connected in parallel, and the two electromagnetic contactors are driven by the response of the limit switch when the energy of the closing spring is completed. The electric power is cut off from the armature circuit and the field circuit of the electric motor at the same time that the dynamic braking circuit is activated, and the CR series circuit and the limit switch are opened.

F. Action When the closing spring is instantly released by the closing operation and the limit switch is closed, both the magnetic contactors for field control and armature control are closed. Current flows through the armature winding. That is, the electric motor is started. On the other hand, a charging current flows through the surge absorbing CR series circuit due to the closing operation of the a contact of the armature controlling electromagnetic contactor. At this time, even if chattering occurs in the limit switch, the contact a of the armature control contactor is closed, and the charging current flows in the CR series circuit, so that the armature control electromagnetic contactor is maintained in the energized state.

When the closing spring is fully charged, the limit switch is opened and the field control and armature control electromagnetic contactors are opened. As a result, the a-contact of the contactor is opened to cut off the energization of the armature circuit and the field circuit of the electric motor, and at the same time, the b-contact of the contactor is closed to activate the dynamic braking circuit. 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 the limit switch 3 is configured to detect the release of the closing spring of the spring operating mechanism of the power breaker and the completion of energy storage. The switch 3 controls the opening / closing operations of the magnetic field controlling electromagnetic contactor 4 and the armature controlling electromagnetic contactor 5, and the electromagnetic contactors 4, 5 are connected to the armature circuit and the field circuit of the closing spring energy storage DC motor. Attaching the dynamic braking circuit constituted by the contacts of the
The same reference numerals are given to the same components, and the description of the configurations will be omitted.

In this embodiment, a contact 5-2a of the armature controlling electromagnetic contactor 5 is connected in series to a surge absorbing CR series circuit including a resistor 7 and a capacitor 8, and the series circuit is connected in parallel to the limit switch 3. Connected.

Next, the operation will be described.

(A) Immediately after closing operation When the closing operation is performed by the closing command, the closing spring is instantly released and the limit switch 3 is turned on. As a result, the electromagnetic contactor 4 for controlling the field is energized, its a contact 4-2a is closed, and a voltage is applied to the field winding 1F. Also, following the energization of the electromagnetic contactor 4,
The armature controlling electromagnetic contactor 5 is energized, and its b-contact 5-
1b is opened and a-contact 5-1a is closed, and voltage is applied to the armature winding 1A. That is, the closing spring storing electric motor is started, and the storing force of the closing spring is started.

In this case, even if chattering occurs in the limit switch 3, the a-contact 5-2a of the armature controlling electromagnetic contactor 5 is closed and the CR series circuit is inserted, and the charging current of this circuit causes both electromagnetic contactors 4 to contact each other. Since the biased states of 5 and 5 are maintained, even if chattering occurs in the limit switch 3, no problem occurs.

(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, the electromagnetic contactors 4 and 5 are deenergized and the a contacts 4-2a and 5-1a are opened, and the armature current and the field current are cut off. At the same time, b contact 4-
When 1b and 5-1b are closed, a short circuit is formed in the motor section, and both terminals of the armature winding 1A and the field winding 1F are short-circuited. 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. The surge absorbing CR series circuit and the limit switch 3 are opened.

H. Effect of the Invention As described above, according to the present invention, since the dynamic braking circuit is provided in the motor section, the closing spring energy storage motor can be stopped in an extremely short time after the hook and the roller are joined. It is possible to prevent the destruction of the roller. Also, since the surge absorption CR series circuit is connected in parallel with the limit switch, the electromagnetic contactor can be reliably energized even when the limit switch chatters, and the control function can be maintained. Moreover, since the contacts of the electromagnetic contactor for armature control are inserted and used only during circuit operation, the reliability of the CR series circuit can be improved. Furthermore, 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 for a power circuit breaker according to the present invention, and FIG. 2 is a circuit diagram for explaining a prior art. 1A ... Armature winding of DC motor for closing spring energy storage, 1F ... Field winding of the same motor, 2 ... Wiring circuit breaker, 3 ... Limit switch for detecting completion of closing spring energy storage, 4 ... Field control Electromagnetic contactor, 5 ... Armature control electromagnetic contactor, 4-1a,
4-2a, 5-1a and 5-2a ... a contact, 4-1b and 5-1b ...
b contact, 7 ... resistor, 8 ... capacitor.

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 surge absorbing CR series circuit connected in parallel with the limit switch via a contact of the armature controlling electromagnetic contactor, and the limit switch when the closing spring is released. The closing operation of the contacts of the armature controlling electromagnetic contactor is performed in response to the above, and the surge absorbing CR series circuit is connected in parallel to the limit switch. At the same time, the response of the limit switch upon completion of energy storage of the closing spring causes
Characterized in that the two electromagnetic contactors are driven to interrupt the energization of the armature circuit and the field circuit of the electric motor and at the same time the dynamic braking circuit is activated, and the CR series circuit and the limit switch are opened. The electric spring control circuit for the closing spring of the power circuit breaker.