JPS5935491Y2 - AC elevator control device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a control device for an AC elevator.

Conventionally, as a control device for an AC elevator, there is one that controls the primary voltage of an induction motor to start the motor, and when the motor reaches a deceleration position after traveling a certain distance, a DC current is passed to the motor from a control rectifier circuit including a thyristor.

This causes the electric motor to generate a braking force and decelerate the elevator car.

In this case, in order to obtain a stable landing system and good riding comfort, a feedback control method is generally introduced to control the thyristor of the control rectifier circuit to generate an appropriate braking force and decelerate the car.

Such a conventional example is shown in FIG. In the figure, R, S, T
is a three-phase AC power supply, 1 to 3 are the primary windings of a three-phase induction motor that drives a car (not shown), 4 to 7 are thyristors, and 8
, 9 are diodes, 103 to 10C are starting electromagnetic contactor contacts that close when the car starts to start and open when deceleration starts, 11a and 11b are deceleration contacts that close when the car starts decelerating and open when starting. 12 is a starting reactor, and 13 is a smoothing reactor.

At the start of startup, the startup electromagnetic contactor contacts 102 to 10C are closed, and the thyristors 4 and 5 are connected in antiparallel to each other,
In an elevator that can control the electric motor from near single-phase torque to three-phase torque by changing the firing angle, a torque exceeding a certain value is required at the start of startup. Determined by

If the torque beyond that is controlled by the thyristors 4 and 5, the torque control range by the thyristors 4 and 5 will be narrowed, the non-conduction period of the current will be eliminated, and the pulsating torque will be reduced, resulting in a low-vibration, low-noise control device. realizable.

Next, at the start of deceleration, the starting contactor contacts 103 to 10
C is open, and contacts 11a and 11b are closed.

Thyristor 6.7 and diodes 8, 9 constitute a full-wave rectifier circuit, and the motor generates braking torque.

Here, the braking torque can be changed by controlling the firing angle of the thyristor 6.7.

The smoothing reactors I to 13 smooth the pulsating current contained in the output of the full-wave rectifier circuit, thereby reducing vibration noise during braking.

However, the starting reactor 12 and the smoothing reactor 13
Since it uses two glue handles, it has the disadvantage of being expensive.

This invention aims to improve the above-mentioned drawbacks, and aims to provide a control device for an AC elevator that can reduce the number of reactors and reduce magnetic noise and mechanical vibration during control.

An embodiment of this invention will be explained below with reference to FIG.

In this embodiment, as is clear from the figure, the thyristor 4
, 5 and the starting reactor 12 is inserted between the aforementioned full-wave rectifier circuit and the primary winding 1 of the motor.

At the start of startup, when the contacts 10a to 10C are closed, the motor generates a torque determined by the reactance of the startup reactor 12, the motor constant, and the applied voltage.

Here, the reactance of the starting reactor 12 is selected to be an appropriate value to ensure smooth starting.

Therefore, the car is started smoothly and the subsequent acceleration is controlled by varying the firing angle of the thyristors 4, 5.

Next, when braking starts, contacts 101 to 10C are opened,
Thyristors 4 and 5 are made non-conductive, and contacts 11a,
11b is closed.

Then, the full-wave rectified DC current is controlled by changing the firing angle of the thyristor 6°7.

This DC current is smoothed through the starting reactor 12 and flows through the primary windings 1 and 2 of the motor.

That is, at this time, the starting reactor 12 acts as a smoothing reactor.

Although this embodiment has one less reactor than the one in Fig. 1, it can obtain the same function as in Fig. 2.
It is inexpensive and can reduce magnetic noise and mechanical vibration.

Figure 3 shows another embodiment in which this invention is applied to reactor starting, where 12 to 14 are reactors for controlling starting torque, 4a, 4b and 5a, 5b are electromagnetic contactors for controlling starting torque. It is a point of contact.

At the start of startup, when the contacts 10a to 10C are closed, a first stage torque is generated, and then the contacts 4a and 4 are opened for a certain period of time.
b closes, generating second stage torque, and finally contact 5a
, 5b are closed to generate third stage torque.

During braking, contacts 10a to 10C14a. 4b, 5a
, 5b are opened, contacts 11a, 11b are closed, and the full-wave rectified direct current is controlled by changing the firing angle of the cyrisk 6.7.

This current is smoothed as it flows through the motor primary windings 1, 2 through the reactor 12.13.

As explained above, in this invention, the starting reactor of the induction motor is controlled by an opening/closing device so that it can also be used as a smoothing reactor for DC braking current during braking. It can be reduced.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a conventional AC elevator control device, Fig. 2 is a circuit diagram showing an embodiment of an AC elevator control device according to this invention, and Fig. 3 is a circuit diagram showing another embodiment of this invention. It is a circuit diagram. 1-3...Primary winding of three-phase induction motor, 4-7
...Thyristor, 8,9...Diode, 10 a to 10C... Magnetic contactor contact for starting, 11 a, 11 b... Electromagnetic for deceleration Contactor contact, 12... Starting reactor. In addition, the same parts or corresponding parts in the figures are indicated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] An induction motor that drives the car, a starting circuit that applies an alternating current voltage to the motor during starting, a rectifier circuit that supplies direct current to the motor during braking to provide DC braking force, and a circuit that is commonly connected to the starting circuit and the rectifying circuit. and a starting reactor inserted between the starting reactor and the electric motor, and a switching device connected in parallel to the starting reactor and opening and closing during the starting and braking to connect the starting reactor to the electric motor. Elevator control device.