JPS62147983A - Controller for ac elevator - Google Patents

Abstract

PURPOSE:To enhance the reliability of the titled device, by using the antiparallel circuit of thyristors, and by controlling the thyristors selectively on the reduced speed operation of an elevator. CONSTITUTION:On the accelerated motion of the upward operation of a cage 1 due to the driving of a three-phase induction motor 5, the firing angles of upward operating antiparallel thyristors 20a, 21a, 24a, 25a, and three phase/single phase change-over antiparallel thyristors 28c, 29c are controlled by a firing circuit 18, and the three phase operation of the motor 5 is executed, and the cage 1 is started. On the accelerated motion of the downward operation of the cage 1, the three phase/single phase change-over antiparallel thyristors 28c, 29c are firing-controlled, and the control of the firing angles by the firing circuit 18 is changed over to the firing control of downward-operating antiparallel thyristors 22b, 23b, 26b, 27b. Besides, on the upward reduced speed operation of the cage 1, each rate 20a, 23b, 25a, 26b of the upward and downward operating antiparallel thyristors is firing-controlled, and on the downward reduced speed operation, each section 21a, 22b, 24a, 27b of the thyristors is firing-controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an AC elevator based on thyristor control of a three-phase induction motor.

[Prior Art] Fig. 4 shows, for example, Japanese Patent Application Laid-Open No. 58-170394-! , is an overall block configuration diagram showing a conventional AC elevator speed control device disclosed in the publication. In the figure, (1) is an elevator car, (2) is a counterweight, (3) is a main rope, (
4) is a drive network vehicle, (5) is a three-phase induction motor, (8a),
(8b) is the magnetic contactor contact for f-drop, (7a), (7b)
J:, Main electromagnetic contactor contact for II (8) is the electromagnetic contactor contact for running, (15) is the speedometer generator, (18) is the speed command generator, (17) is the adder, (18) ) is the ignition circuit, (R).

(S), (T) are three-phase AC power supplies, (21), (22) are the first thyristors connected in antiparallel and inserted between the power supply R and the contact (6a), (23), ( 24) is also a first thyristor inserted between the power supply S and the contact (6b),
(25) is the power supply R side of the first thyristor (21), (22) and the electric motor (5) of the first thyristor (23), (24).
) side, the second thyristor (2B) is connected to the '1E source S side of the first thyristors (23), (24) and the motor (5) side of the first thyristors (21), (22). This is the second thyristor. Next, the operation of the conventional device will be explained based on the configuration described in "2".

When starting the L-up operation, the contacts (8a), (eb), and (8) are closed, and the ignition circuit (18) turns on the first thyristor (
21) to (24) are controlled in firing phase, and the second thyristors (25) and (2B) are not fired. Now, Figure 5 (a)
) (the thyristor symbols are shown in the figure).

When the car (1) reaches the deceleration command point A, the contact (8) is opened, resulting in the circuit shown in FIG. 5(b). When the deviation signal Ve becomes negative, the firing circuit (18) stops the firing phase control of the first thyristors (21) and (23),
The firing phase of the thyristors (22), (24) to (26) is controlled. This results in the circuit shown in FIG. 5(C). Switching from FIG. 5(b) to FIG. 5(C) is instantaneously performed by mechanically switching the one-firing circuit (18) without using contactor contacts.

In addition, in the circuit of FIG. 5(C) during deceleration, the firing phase control of the thyristors (22) and (2B) by speed feedback control is not performed, and the firing period of the power supplies R and S is always in the firing state.
It would be even more desirable if the flywheel current flowing to the electric motor (5) was made to flow through the thyristors (22) and (2Ei). That is,
When all the thyristors (22), (24) to (26) are controlled in firing phase, the current II flowing through the motor (5)
is an intermittent current as shown in Figure 6, whereas
The flywheel current results in a continuous current I2 with little ripple. As a result, the torque fluctuation of the electric motor (5) is reduced, the riding comfort of the car (1) is improved, and
The noise j'f generated from the electric motor (5) is also reduced.

Note that each of the first thyristors (21), (22) and the first thyristors (23), (24) may be configured as a bidirectional thyristor.

[Problems to be Solved by the Invention] Since the conventional speed control device for an AC elevator is configured as described above, switching between the elevator's "two-up" and "downward" operations depends on the contact operation of the electromagnetic contactor contact. Therefore, due to wear and tear of the contacts due to changes over time, etc.
The reliability of the switching control operation decreases, and from the perspective of the utilization efficiency of the thyristors used, some thyristors (25) and (2)
B) is used only when braking the electric motor and is another thyristor (22).

Since (24) is used not only during braking but also when accelerating the motor and at constant speed, if the ratings of all the thyristors used are determined according to thyristors (22) and (24), thyristors (21), (23), (25), (2B)
has too much thermal margin and becomes uneconomical. In order to solve this problem, if the rating of each thyristor is selected separately, the shapes will be different and it will be difficult to implement. Furthermore, a module thyristor that is a combination of multiple thyristors cannot be used. For these reasons, conventional devices have had problems in terms of miniaturization, cost reduction, and energy saving of the device.

This invention was made in order to solve the above-mentioned problems.
In addition to replacing mechanical contacts with reduced performance with thyristors,
It is an object of the present invention to provide a control device for an AC elevator capable of controlling rotation in the first direction and braking of the elevator without imposing a heavy load on only a specific thyristor.

[Means for Solving the Problems] A control device for an AC elevator according to the present invention includes an anti-parallel thyristor for upward operation and a downward operation connected to at least two phases of a Sanwa style conductive motor that drives an elevator car. Equipped with anti-parallel thyristors for directional operation to operate the elevator in the vertical direction, and when braking the electric motor, ignition control of a part of the anti-parallel thyristor for forward rotation in the north direction and a part of the anti-parallel thyristor for downward operation is performed. By doing so, DC braking is applied to the motor.

[Function] The control device for an AC elevator according to the present invention is 1
For one-way operation, the firing angle of two sets of anti-parallel thyristors is controlled to control the forward torque to start the car in two directions, and for downward operation, another 2 Ml anti-parallel thyristor is used. The car is started in the F direction by controlling the firing angle of During downward operation deceleration braking, the thyristor not used above is used to apply direct current braking to the motor.

[Embodiment] FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.
(1) to (5), (+5) to (18) are completely the same as the above conventional device, and (20a), (21a), (2
4a).

(25a) are thyristors constituting an inverse parallel thyristor for northbound operation, (22b), (23b), (26b), (
27b) is a thyristor constituting an anti-parallel thyristor for downward operation; (28c) and (29c) are thyristors constituting an anti-parallel thyristor for three-phase/single-phase switching.

Next, the operation of this embodiment will be explained based on the above structure.

When the car (1) is accelerated in the upward direction by the drive of the three-phase induction motor (5), the anti-parallel thyristor (20
a) , (21a) , (24a) , (25a
) and three-phase/? Antiparallel thyristor for ti phase switching (28
c) The firing angles of (29c) are controlled by the firing circuit (8), and the electric motor (5) is operated in two-phase mode, so that the car (
1) Start.

Next, when the car (1) is accelerated in the downward direction, similarly, the misphase/
Antiparallel thyristor for width phase switching (28c), (29c
) is controlled by uI to perform two-phase operation, and the firing angle of the thyristor is controlled by the firing circuit (18) to the anti-parallel thyristor (22b) for downward operation.

(23b), (2[ib), and (27b) to switch the phase of the motor (5), change the phase rotation direction, and start the car (+).

In addition, when car (1) is decelerating in the north direction,
- part (20a) of the anti-parallel thyristor for directional operation.

The firing angles of (23b), (25a), and (28b) are controlled to form the thyristor circuit shown in FIG. 2(a), and the radio wave current flowing through the motor (4) is controlled to apply DC braking. Decelerate car (1).

Next, when the car (1) is decelerated in the downward direction, it is
), (22b), (24a), and (27b) to form the thyristor circuit shown in Fig. 2(b), and direct current flowing through electric motor a (4) during upward operation. ,
Control is performed in the opposite direction to apply DC braking to decelerate the car (1).

Figure 3 shows the speed command signal. VPo is the speed signal when the car runs at the rated speed determined by the number of poles of the induction motor and the frequency of the power supply, and VPI is the speed signal when the distance from the start floor to the stop floor is short. This is a speed command signal when the car is run at a speed that does not reach the rated speed.

When the speed command signal is VPO, when accelerating to the rated speed, the induction motor is excited with three-phase AC until the deceleration start point, and a thyristor is also used when the motor generates braking force, such as NLU or FLD. Full fire (all ignition)
This allows the mechanical energy to be returned to the power source. A
After the point, speed command signal 1, 'fvP and speed detection signal -'i
The thyristor to be controlled is selected depending on the positive/negative of the deviation signal ve from y, and the induction motor is caused to run or to DC braking.

On the other hand, as in V1・1, when the speed is not accelerated to the rated speed, the difference between VP and Vl is maintained even during constant speed operation.
Select the thyristor controlled by lE negative and select the torque of the induction and q motors for power and braking to operate the car.

In addition, three-phase/? The n-phase switching does not necessarily require the use of a thyristor; mechanical contacts can also be used. However, this is not preferable since the on/off operation of the contact is required to switch the torque during forward driving and forward rotation during braking.

Effects of IJI from L] As described above, according to the present invention, an anti-parallel circuit of thyristors is used without using mechanical contacts for switching the operating direction of the elevator, and these thyristors are selectively controlled during deceleration operation of the elevator. By doing this, we configured the induction motor for driving the elevator car to apply DC braking.
The reliability of the device ν1 is improved, and an inexpensive and compact AC elevator control device can be obtained.

[Brief explanation of drawings]

The connection conversion diagram of each thyristor during braking, Fig. 3 is an elevator operating characteristic diagram, and Fig. 4 is a diagram of ``It!'' during conventional braking. : A flow waveform diagram. In the figure, (1) is the elevator car, (5) is the three-phase induction motor, and (18) is the ignition circuit. (20a), (21a), (24a), (25a) are anti-parallel thyristors for upward operation; (22b), (23b), (28b), (27b);
) is an anti-parallel thyristor for downward operation. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2 Figure 0a Figure 3 Figure 4 Procedural amendment (voluntary) 21 Name of invention; C control device for AC elevator 3; Person making amendment 6; Contents of amendment (1 ) The description “thyristor (22), (26) J” on page 3, line 18 to line 19 of the specification has been replaced with “thyristor (22), (26) J”.
4). (26) Correct as J. (2) Thyristor (22) on page 4, line 2 of the specification. (26) J is replaced by “thyristor (24), (26)
) Correct as J. (3) In the drawings, correct Figure 4 as shown in the attached sheet. 7. At least 1 copy of the revised drawings of attached documents

Claims (2)

[Claims] (1) An anti-parallel thyristor for upward operation and an anti-parallel thyristor for downward operation are connected to an AC power source and connected to at least two phases of a three-phase induction motor that drives a car, and when braking, the 1. A control device for an AC elevator, comprising an ignition circuit that causes a motor to be DC-braked by a part of an anti-parallel thyristor for directional operation and a part of an anti-parallel thyristor for downward operation. (2) The ignition circuit according to claim 1, is characterized in that, during upward braking, the ignition circuit performs gate control to flow current through a thyristor that did not conduct current during downward braking. AC elevator control device.