JPS6087176A - Emergency controller for elevator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an emergency control system for an elevator, and more particularly to an emergency control system for an elevator that shortens the stopping distance during an emergency stop.

[Prior art]

An elevator moves passengers by moving a lobe connected to a car up and down by a hoisting motor, thereby moving a seat up and down. In this case, in recent years, it has been proposed to use an induction motor as the hoisting motor and to control this induction motor with a variable voltage/variable frequency power source.

FIG. 1 is a circuit diagram showing an example of an elevator controlled by the above-mentioned variable voltage/variable frequency power supply, in which three-phase commercial power is converted to direct current in converter 1 and then supplied to inverter 2. .

The inverter 2 converts the input DC power into a three-phase variable voltage/variable frequency power and then supplies the power to the induction motor 4 as a hoisting motor via contacts 38 to 3C. Therefore, the induction motor 4 rotates according to the frequency and voltage of the power supplied from the inverter 2. When the induction motor 4 rotates, the sheave 5 connected to the rotating shaft winds up or unwinds the lobe 6, thereby lifting the heel 7 and the counterweight provided at both ends of the rope 6. Perform 8 up and down movements.

A brake drum 2m 9 is attached to the rotating shaft of the sheave 5, and a shoe 11 provided on a part of the arm 10 is pressed against the outer periphery of the brake drum 9 by the reaction force of a spring 120. Performs multiple controls. Further, the regenerative output of the induction motor 4 is returned to the three-phase commercial power source as regenerative power via the inverter 29 and the regenerative converter 13.

On the other hand, a speed detector 14 is provided on the output shaft of the induction motor 4, and a speed signal A corresponding to the rotational speed of the induction motor 4 is generated from the speed detector 14. The difference between this speed signal A and the speed command signal B generated from the speed pattern generator [15] is calculated in an adder 16, and the difference signal is supplied to the speed control device 17. When the speed control device 17 receives the deviation signal, it generates a voltage control signal C and a current control signal for controlling the deviation signal to zero, and supplies them to the voltage control signal 18 and the current control device 19. The voltage control device 18 controls the voltage of the DC output power supply supplied to the inverter 2 by controlling the gate circuits of the thyristors forming the converter 1 and the regenerative converter 13 in accordance with the voltage control signal C. In addition, the current control device 19 configures the input/(-p 2 ) according to the current control signal. The base N of the transistor
The output current of the three-phase AC power supply is controlled by controlling the current. Therefore, converter 1. Inverter 2° speed control device 1T, voltage control device 18 and current control device 19
constitutes a variable voltage/variable current control power supply unit that performs power supply control for controlling rotation in accordance with the speed command signal B output from the speed pattern generator 15. Note that 2a is a capacitor that smoothes the output of the converter 1. In addition, FIG. 2 shows the converter 12 and the regeneration converter 13. 1 is a circuit diagram showing a specific example of an inverter 2, in which the converter 1 is composed of thyristors 1a to 1f, and the regenerative converter 13 is composed of thyristors 13a to 1f.
3f.

Further, the inverter 2 is composed of transistors T1 to T6.

Fig. 3 shows the abnormality control section, 20 is a safety circuit that detects abnormalities in the elevator and executes safety control in an emergency, and 21 is connected to the power line (G) via the safety circuit 20 (→
22 is a brake coil connected in parallel to the emergency operation relay 21, and 23 is connected to the power line 0- through the normally open contact 21a of the emergency operation relay 21.
) and (f), and its contacts 3a to 3C are connected between each line between the inverter 2 and the induction motor 4 shown in FIG.

FIG. 4 is a block diagram showing an example of the voltage control device shown in FIG. 1, in which the voltage supplied from the speed control device 17 is Gate control signals 1ag to 1fg and 13dg to 131g for obtaining an output voltage according to control signal C are generated.

FIG. 5 is a block diagram showing an example of the current control device 19 shown in FIG.
During the period when d is open, each transistor T1 forming the inverter 2 generates a pace voltage T, 1g-T6g to obtain a current according to the current control signal supplied from the speed control device 17. ~Feeds at a pace of T.

In a circuit configured in this way, when an abnormality occurs in the elevator, the safety circuit 20 is activated and the emergency operation relay 2 is activated.
1 and brake coil 22 are deenergized. When the emergency operation relay 21 is deenergized, its normally open contact 21 closes, so the power switch 23 operates and opens the contacts 3B to 3c, thereby cutting off the power supply to the induction motor 4. .

On the other hand, when the brake coil 22 is deenergized, the attraction to the brake arm 10 is released, so this arm 10 becomes free and the brake shoe 11 is pressed against the brake drum 9 by the force of the spring 12, causing the brake shoe 11 to be pressed against the brake drum 9. car 5
The brake is applied to Further, when the emergency operation relay 21 is deenergized, its contacts 21c and 21d close, so the voltage control device 18 and the current control device 19 become inoperable, and the outputs of the converter 1 and the inverter 2 are cut off.

In the elevator emergency control system having the above configuration, the induction motor 40 torque TM and the load torque TL are matched at the point P shown in FIG. , ω1, the brake torque is not applied due to the delay in the operation of the safety circuit 20, and the vehicle accelerates with the torque TL'. Then, when the brake torque TB is gradually generated and TL=TB, the acceleration operation is completed and thereafter the vehicle is decelerated and stopped by the braking torque of TB-TL. In this case, the motor torque, brake torque, load torque, composite torque, and rotational speed are as shown in FIGS. 6(a) to 6(e).

However, the elevator emergency control system having the above structure has a problem in that the stopping distance becomes long because the elevator accelerates once and then stops as shown in FIG.

[Summary of the invention]

Therefore, the elevator emergency control device according to the present invention is intended to prevent an increase in the stopping distance during an emergency stop, and applies DC power to the induction motor during an emergency stop.

[Embodiments of the invention]

FIG. 8 is a circuit diagram showing an embodiment of an elevator emergency control system according to the present invention, and the same parts as in FIG. 1 are indicated using the same symbols. In the figure, 3d and 3e are normally closed contacts of the power switch 23, which are connected between the output end of the converter 1 and the two-man line of the induction motor 4.

This configuration is shown in FIG. 9 using a specific circuit. However, in this case, the power switch 23
It is assumed that the voltage control device 18 performs control so that the converter 1 continues to generate DC output even if the converter 1 operates.

In the circuit configured in this manner, when the safety circuit 20 shown in FIG. 3 is activated and the power switch 23 is energized, the contacts 3&-3e are switched to the state shown in the figure. The output of the inverter 2 is cut off from being supplied to the induction motor 4, and the DC output of the converter 1 is supplied to the induction motor 4.
is supplied only to two selected coils 4a and 4c. As a result, the current flows through the cone park 1, the contact 3d, the coil 4a, the coil 4c, the contact 3e, and the path M of the converter 1. When direct current is passed through the induction motor 4, a braking torque as shown in FIG. 10 is generated, and this braking torque To is approximately proportional to the square of the direct current. Therefore, the voltage control device 18 controls the converter 1 so that the braking torque To becomes an appropriate value (1 to 3 times the rated torque of the motor).

In this case, if we look at the relationships among the motor torque, brake torque, braking torque due to DC current, load torque, composite torque, and rotational speed, the relationship will be as shown in Figures 11 (a) to (f), and Figure 6. Comparing (a) to (e), we can see that braking is applied without time delay by the amount of braking torque generated by DC current, and that the car speed is increased accordingly. The car can be stopped reliably with a short braking distance since the car starts decelerating without any brakes. Furthermore, the voltage control device 18 controls the converter according to the driving direction of the car and the magnitude of the load, thereby making the system more efficient.

In the above embodiment, a new contact point 3d is provided.

3e is provided to apply direct current to the induction motor in an emergency.
A similar effect can be obtained by controlling the terminals 38 to 3C and the converter 1 and inverter 2 to continue operating during emergency control. If one of the transistors T1 + T2 fails, a similar braking force can be obtained by passing direct current through only the two coils that constitute the induction motor 4 in combination with other transistors.

Note that FIG. 12 shows the output voltage of the comparator 1 during normal operation, and in order to control the current to the induction motor 4 using this DC voltage as a power source, for example, the operation of the transistors T1 to T6 as shown in Table 1 below is necessary. It would be a good idea to control it.

Table 1 [Effects of the Invention] As explained above, since the elevator emergency control device according to the present invention applies DC braking to the induction motor during emergency control, it can achieve short braking distance without causing time delay. The car can be stopped reliably. Further, since the mechanical brake can be reduced in size and weight due to DC braking, it has various excellent effects such as being able to construct an inexpensive system.

[Brief explanation of drawings]

1 and 3 are circuit diagrams showing an example of a conventional elevator emergency control system, and FIGS. 2, 4, and 5 are circuit diagrams showing specific examples of each part of the circuit shown in FIG. 6 and 7 are operation waveform diagrams of each part for explaining the operation of the circuit shown in FIGS. 1 to 5, FIGS. 8 and 9 are circuit diagrams showing an embodiment according to the present invention, and FIG. 1 to 12 are operation waveform diagrams of various parts of the circuit shown in FIGS. 8 and 9. 1...Converter, 2...Inverter, 3a to 3e
...Contact, 4...Induction motor, 5...Sheave, 6...
...rope, 7...basket, 8...counterweight, 9...
Brake tom 2, 1°...7-A, 11...Brake shoe, 12...Spring, 13...Regeneration converter, 14...Speed detector, 15...Speed pattern generation Device, 16... Adder, 17... Speed control device,
18... Voltage control device, 19... Current control device. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Oiwa Masu Ja (2 others) Fang 3 Xi Tym Figure 6 Figure 1I Figure 1/L\ Bamboo and Figure 12 procedural amendment (voluntary) 1. Indication of the case Patent Application No. 194885-1982 2. Title of the invention Elevator emergency control device 3, person making the amendment 5, subject of the amendment (1) Column for detailed explanation of the invention of the clear site (23 Drawing 6, contents of amendment (1) Specification letter page 3, line 3 "Control" is corrected to "braking." (2) On page 5, lines 13 to 14, "Gate control signal..." is written as "Gate control signal...". Generated gates 18g~If, , 13.g~13f
Apply to g. ” he corrected. (3) Page 5, lines 19 to m “Base voltage T1□
The phrase "by generating ~T6g" is corrected to "by generating a base current." (4) Page 6, line 1, "Supplied to the bases of T1 to T6." r Bases of T1 to T6 Tj g - T6g
supply to. ” he corrected. (5) On page 6, line 6 of the same page, replace the phrase ``from closing,'' with ``
"From opening," he corrected. (6) On page 8, line 14, "energize" is corrected to "deenergize." (7) Page 10, lines 13 to 17 “In addition,...
...It's going to be a good thing. ” will be deleted. (8) Delete all of Table 1 on page 11. (9) Figures 2 and 11 of the drawings will be corrected as shown in the attached sheet. 7゜ Attached documents (1) One amended drawing

Claims (1)

[Claims] (1) In an elevator that has an induction motor as a hoisting motor and a variable voltage/frequency power source that controls the rotation of the induction motor, there is a safety circuit that detects abnormalities in the elevator, and when the safety circuit is activated, An emergency control device for an elevator, comprising: a DC application circuit that supplies DC current to an induction motor to generate DC braking force.