KR900010215Y1 - Control devices of elevator of alternating current - Google Patents

Abstract

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Description

Control device of AC elevator

1 is a block diagram showing an apparatus for controlling an alternating current elevator according to an embodiment of the present invention.

2a and 2b are explanatory diagrams of FIG.

FIG. 3A is a sequence diagram illustrating the operation of each thyristor of FIG.

3b is an operation characteristic diagram of an elevator.

4 is a detailed explanatory diagram of the firing circuit of FIG.

5 is an explanatory diagram of phase control of a firing circuit.

6 is an operation explanatory diagram of each thyristor under phase control.

7 is a configuration diagram showing a control device of a conventional AC elevator.

8A and 8B are explanatory diagrams of FIG.

Fig. 8C is a diagram of current waveforms when braking the motor.

FIG. 9 is a sequence diagram illustrating each thyristor operation of FIG. 7. FIG.

* Explanation of symbols for main parts of the drawings

20a, 21a, 24a, 25a: Thyristor group constituting the anti-parallel thyristor for upward operation

22b, 23b, 26b, 27b,: thyristor group constituting anti-parallel thyristor for downward driving

28c, 29c: thyristor group constituting anti-parallel thyristor for three-phase / single-phase switching

The present invention relates to a control device of an AC elevator based on thyristor control of a three-phase induction motor.

7 is an overall block diagram showing a speed control device of a conventional AC elevator shown in Japanese Patent Laid-Open No. 58-170394. In the drawing, 1 is an elevator car (hereinafter abbreviated as car). 2 is a counterweight, 3 is a rope, 4 is a drive pulley, 5 is a 3-phase induction motor, 6a and 6b are checks for the rising magnetic contactor, 7a and 7b are the falling contactor contacts, 8 is the driving contactor contact, and 15 is Generator for speedometer, 16 is speed command generator, 17 is subtractor, 18 is firing circuit, R, S, T is three-phase AC power supply, 21, 22 are in parallel and connected in parallel to each other. The first thyristor, 23, 24 inserted into the second thyristor, similarly inserted between the power supply S and the contact 6b, 25 is the power supply R connection terminal side of the first thyristor 21, 22, The third thyristor connected to the connection terminal side of the electric motor 5 of the two thyristors 23 and 24, 26 is the power supply s connection terminal side of the second thyristor 23 and 24 and the first thyristor 21. Reference numeral 22 is a fourth thyristor connected to the motor 5 connection terminal side.

Next, the operation of the conventional apparatus will be described with the above configuration.

During the upward motion start, the contacts 6a, 6b, 8 are closed and the first and second thyristors 21, 24 are controlled by the firing circuit 18 to control the phase of the third and fourth thyristors 25. (26) is not fired, which results in the circuit of FIG. 8a.

When the car 1 reaches the deceleration command point A (FIG. 9), the contact point 8 is opened, and when the deviation signal Ve becomes (-), the call of the thyristors 21 and 23 is performed by the firing circuit 18. The phase control is stopped and the thyristors 22, 24, and 26 are controlled by firing phase, which results in the circuit of Fig. 8B.

In this case, the thyristors 24 and 26 are always conducted by the circuit of FIG. 8B despite the rise and fall during deceleration.

The reason why the thyristors 24 and 26 are conducted in this manner is that the flywheel current flowing through the electric motor 5 flows through the thyristors 24 and 26 to become more preferable.

That is, when all the thyristors 22, 24, and 26 are controlled by the phase of firing, the current I1 flowing through the motor 5 becomes an interrupted current as shown in FIG. 8C, while the ripple is caused by the flywheel current. The less continuous current I2 becomes.

As a result, the torque fluctuation of the electric motor 5 becomes small, and the boarding feeling of the car 1 becomes good, and the noise which the motor 5 produces | generates also reduces.

The first thyristor 21, 22 and the second thyristor 23, 24 may be constituted by bidirectional thyristors, respectively.

By the way, the current which each thyristor receives from acceleration to deceleration is shown in FIG.

As is apparent from this figure, the current sharing varies greatly with the thyristor.

Therefore, if the thyristor is set to the same rating and determined in accordance with the thyristor 24, other thyristors are thermally excessive and uneconomical.

Determining the thyristor rating according to this current sharing is not desirable because the number of parts increases or the workability worsens.

The hatched line in FIG. 9 represents the thyristor which is full fire in control, the top curve is the speed curve, and the following represents the current sharing section of each thyristor.

Since the control device of the conventional alternator is configured as described above, the same thyristor among the individual thyristors is used for reverse operation or DC braking force. As a result, the current sharing of the individual thyristors becomes uneven and the thyristor is rated economically. In the thyristor circuit, since the thyristor is inserted only in two phases, when the thyristor phase is controlled at the start of the car, an unbalanced current flows to the motor, resulting in high noise and high energy consumption.

In addition, when the deceleration driving command is generated, the motor is switched to the single-phase driving by the opening of the mechanical contact 8, so that the operation of the contact is delayed, resulting in undesirable riding comfort.

This invention has been invented to solve the problems described above, and aims to obtain an AC elevator control device capable of averaging the current sharing of individual thyristors and at the same time excluding mechanical contacts to realize safe operation. It is done.

The control device of the AC elevator according to the present invention is provided with an upward parallel reverse thyristor for up-down operation and a downward parallel reverse thyristor connected to each of the two phases of a three-phase induction motor for driving a car, so that the elevator can be operated up and down. At the same time, when braking the motor, DC braking is applied to the motor by controlling the part of the upward parallel anti-parallel thyristor and the partial downward antiparallel thyristor.

In this design, the control device of the alternating current elevator controls the firing angle of two sets of anti-parallel thyristors in the upward direction to control the reverse torque, and starts the car in the upward direction. By controlling the firing angle, the car is started downward, and when braking upwards and downwards, the DC motor is braked by using a part of the thyristor used for the upward movement and a part of the thyristor used for the downward driving. At the same time, direct current braking is performed using a thyristor not used above.

The control device of the alternating current elevator according to this design controls the car's upward driving thyristor and the car's downward driving thyristor individually, and raises or lowers the car and simultaneously A firing circuit is provided for each thyristor to be pre-ignition control and firing control so that each thyristor becomes a single phase mixed bridge rectifier circuit with respect to a three-phase induction motor.

The firing circuit according to the present invention performs a reverse operation of the motor by braking the individual thyristors according to the up or down operation of the car, and at the same time, the thyristor of some of the corresponding thyristors according to the deceleration operation direction during the deceleration command operation of the car. A single-phase mixed-bridge rectifier circuit can be formed for a three-phase induction motor by controlling and controlling all the other thyristors to freewheeling diodes to form a DC braking circuit, so that the transfer balancer can balance the current.

1 is an overall configuration diagram showing an embodiment of the present invention, and (1)-(5) and (15)-(18) are the same as those of the conventional apparatus (20a) (21a) (24a) (25a). Are the thyristor groups constituting the antiparallel thyristor for upward operation, (22b), (23b), (26b), and (27b) are the thyristor groups constituting the downward parallel antiparallel thyristor, (28c) (29c). ) Is a group of thyristors constituting the anti-parallel thyristors for three-phase / single-phase switching.

Next, the operation of this embodiment will be described in accordance with the above configuration.

When the car 1 is accelerated in the upward direction by the driving of the three-phase induction motor, the reverse parallel thyristors 20a, 21a, 24a and 25a for the upward operation and the reverse parallel thyristor 28c for the three-phase / single phase switching. The firing angle of the blade 29c is controlled by the firing circuit 8 to perform three-phase operation of the motor 5 to start the car 1.

Next, at the time of accelerating the downward movement of the car 1, the three-phase operation is performed by controlling the three-phase / single-phase switching of the anti-parallel thyristors 28c and 29c in the same manner, and by the firing circuit 18, The control of the firing angle of the thyristors is switched to the reverse parallel thyristors 22b, 23b, 26b, and 27b for the downward driving, and the phase change of the motor 5 is performed to switch the upward rotation direction. Start up.

In addition, in the upward deceleration operation of the car 1, the thyristor shown in Fig. 2a is formed by controlling the firing angles of the parts 20a, 23b, 25a, and 26b of the reverse parallel thyristor for the upward and downward driving. Then, DC current flowing through the motor 5 is controlled to apply DC braking to decelerate the car 1.

Next, during the deceleration operation of the car 1, the firing angles of the parts 21a, 22b, 24a, and 27b of the antiparallel thyristor for the upward and downward operation are controlled as shown in FIG. The thyristor circuit shown in the figure is configured to control the direct current flowing in the motor 5 in the opposite direction as in the upward operation to apply the DC braking to decelerate the car 1.

3A shows the speed command signal.

Vpo is a speed signal when driving a car at the rated speed determined by the number of poles of the induction motor and the frequency of the power supply, and Vp1 drives the car at a speed that does not reach the rated speed when the distance from the start floor to the stop floor is short. This is the speed command signal.

When the speed command signal accelerates to the rated speed like Vpo, the induction motor is excited by three-phase alternating current until the reduction start point, and the machine energy is supplied to the power supply by igniting the thyristors where the motor generates braking force such as no load rise and full load. I'm coming back.

A point falling is to select a thyristor controlled by (+) (-) of the deviation signal Ve of the speed command signal Vp and the speed detection signal Vt to reverse or DC brake the induction motor.

On the other hand, if the motor is not accelerated to the rated speed as Vp1, the thyristor to be controlled by the positive signal (-) of the deviation signal between Vp and Vt is selected and the torque of the induction motor is selected as braking even in the constant speed operation. do.

Here, in the upward deceleration operation, the anti-parallel thyristors 26b and 25a in FIG. 2A do not carry out the firing phase control by the speed feedback control, and the half cycle of the AC power supply R, S is always energized. When the flywheel current flowing through the electric motor 5 flows through the thyristors 26b and 25a during the upward deceleration operation, the electric current can be smoothed and the boarding of the elevator The steel is good and the motor noise is reduced.

In the downward deceleration operation, if the anti-parallel thyristors 21a and 22b in FIG. 2B are always in the conduction state by all arcs as described above, the same good effects as described above can be obtained.

As described above, the thyristors constituting the braking circuits at the time of the upward deceleration operation and the downward deceleration operation are separated from the (20a), (23b), (26b) (25a) and (21a) (22b) (27b) (24a). Furthermore, as described above, the thyristor for allowing the flywheel current to flow is connected to the S phase at the upper deceleration (26b) 25a and to the R phase at the lower deceleration (21a) (22b). ).

For this reason, as shown in FIG. 3, the thermal balance of each thyristor becomes favorable.

In particular, in recent years, the anti-parallel thyristors are buried in one packaging, but the use of these thyristors in the same way as in the present invention has the advantage that the thermal balance between each package (also referred to as the mode is Lister) is good.

4 is an example of an internal circuit of the firing circuit 18. As shown in FIG.

HRS, HST, and HTR are phase control circuits that change phases according to the deviation circuit ε of the input, respectively.

If the output of this phase control circuit is hR, hS, hT, this output becomes as shown in FIG.

5 shows a representative example of hR.

The output pulses whose output pulses are delayed by the control angle a are similarly output for the phase voltages, the phases S-T, and the T-Rs, respectively.

Next, A20-A27 and B20-B27 are AND circuits C22, C21, C26, and C25 are OR circuits, and IN1-IN5 are inverters for converting an H signal to L and an L signal to H.

IF1 and IF2 surrounded by a dashed line are interface circuits, and are electrically insulated so that signals are transmitted by the photocoupler.

The interior of IF1 and IF2 has the same circuit for each input / output.

Representative examples are given in IF1 and IF2.

When B23 becomes H, the diode 24 of the photocoupler emits light and conducts transistor T24 of IF2 to supply the gate input to the gate G24 from the power supply E, and the thyristor starts firing.

Where r1 and r2 are resistors and E is a direct current power source.

Next, the signals CAL, OAL, CDL and C are controlled as shown in FIG. 6 in the rising and falling operation.

Because of this, the controllable thyristor is in the same sequence as in FIG.

This thyristor control sequence can be obtained simply from FIG. 4 and FIG.

In FIG. 3, the oblique portion becomes CDL or L during control, and the output of thyristor C22, C21 or C25, C26 is always H when the inverter is inverted and the H input is inputted to the OR circuit, thereby the thyristor 21a (22b). Or thyristors 25a and 26b are always conducting, and thyristors connected to S-phase or R-phase of the full-current rectifying circuits of FIGS. 2a and 2b become like diodes to become quasi-bridge circuits, and smooth the current of the motor. .

In addition, the change in the thyristor which always conducts during the up and down operation is made by averaging the thyristor load so that only a specific thyristor is excessively used so as not to cause unbalance of the temperature rise.

As described above, according to the present invention, an anti-parallel thyristor for upward operation and an anti-parallel thyristor for downward operation are provided so that the thyristor can be selectively controlled during elevator deceleration and connected to the first phase during upward deceleration operation. Since the thyristor connected to the second phase and the thyristor connected to the second phase are always in a conducting state during the downward deceleration, the transfer thyristor can be used in a well balanced manner, and the device can be compactly and economically configured.

Claims (5)

In an alternator operated by a three-phase induction motor (5) driven by three-phase alternation, a) the first phase (R) and the second phase (S) of the three-phase alternating current power supply and the electric motor (5). A thyristor circuit for ascending operation having first and second anti-parallel thyristors 20a, 21a, 24a, and 25a connected respectively between and b) the first phase of the three-phase AC power supply ( The third and fourth anti-parallel thyristors 22b and 23b respectively provided between R) and the second phase S and the electric motor 5, and respectively provided in parallel with the upward driving thyristor circuit. A thyristor circuit for lowering operation having (26b) and (27b); and c) a plurality of thyristors (3) installed between the third phase (T) of the three-phase AC power supply and the electric motor (5) A three-phase / single-phase switching thyristor circuit having 28c) and 29c; and d) when the motor 5 is driven by DC braking, Wherein the selected one of the thyristors and the one of the selected thyristors in the down-driving thyristor circuit are conductingly controlled, and the selected thyristors are different from each other in the up-and-down operation. When the electric motor 5 is driven in the reverse direction, any one of the ascending operation thyristor circuits 20a, 21a, 24a and 25a and the descending thyristor circuits 22b, 23b, 26b and 27b. An alternating current elevator control apparatus in which one circuit and the three-phase / single-phase switching thyristor circuit (28c, 29c) are electrically controlled. The first thyristor 20a selected from one of the up thyristor circuits 20a, 21a, 24a, and 25a during the DC driving during the ascending operation, and the descending operation. The second thyristor 23b, which is selected from one of the thyristor circuits 22b, 23b, 26b, and 27b, is provided in the opposite direction to the selected first thyristor 20a. A first thyristor which is electrically conductively controlled and is selected from other circuits of the thyristor circuits 22b, 23b, 26b, 27b for the lowering operation, and is provided in the same polarity with the selected first thyristor 20a. Second thyristor 25a selected from another circuit among the 26b and the thyristor circuits 20a, 21a, 24a and 25a for the rising operation and provided in the same polarity with the selected second thyristor 23b. Control device of an alternating current elevator 4. The thyristor (22b) according to claim 3, wherein the second thyristor (21a) selected from the one up thyristor circuit and the first thyristor (22b) selected from the one down thyristor circuit during the DC braking during the down operation. Is connected to each other, and the second thyristor 27b selected in the other down-driving thyristor circuit and the first thyristor 24a selected in the other up-driving thyristor circuit are mutually connected. A control circuit of an alternating current elevator that is connected in a controlled manner. 2. The thyristor circuit according to claim 1, wherein the thyristor circuit has a three-phase induction motor (5) for driving the elevator car (1) based on a three-phase alternating current power supply, and each phase (R) (S) (T) of the three-phase power supply. And parallel phase thyristors 20a, 21a, 24a, 25a, 28c and 29c for the upward direction operation of the elevator car 1 respectively connected between each phase of the < RTI ID = 0.0 > An elevator connected between the first phase R of the AC power supply and the second phase of the three-phase induction motor 5 and between the second phase S of the three-phase AC power supply and the first phase of the three-phase induction motor 5, respectively. The parallel thyristors 22b, 23b, 26b and 27b for the downward direction driving of the car 1 and the inverse parallel thyristors for the upward and downward driving of the elevator car 1 are controlled at the same time, During upward deceleration operation by DC braking using a part of the antiparallel thyristor for driving and downward driving, each thyristor 20a, 23b connected to the first phase is controlled by the firing angle and at the same time. Connected Each thyristor 24a, 26b is fully call-in, and at the time of downward deceleration operation, each thyristor 21a, 22b is connected to the first-phase, and each thyristor 24a is connected to a 2nd phase. A control device for an alternating current elevator, characterized by comprising a firing circuit (18) for controlling the firing angle (27b).