BRAKE CONTROLLER, ELEVATOR SYSTEM AND A METHOD FOR PERFORMING AN EMERGENCY STOP WITH AN ELEVATOR HOISTING MACHINE DRIVEN WITH A FREQUENCY CONVERTER

• US 20150053507A1
• Filed: 11/05/2014
• Published: 02/26/2015
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Kone Corporation
• Original Assignee: Kone Corporation
• Inventors: Kattainen, Ari, Saarikoski, Tapio, Stolt, Lauri, Kallioniemi, Antti, Raassina, Pasi, Nakari, Arto
• Granted Patent: US 9,873,591 B2
• Time in Patent Office: Days
• US Class Current: 187/288
• CPC Class Codes: B66B 1/30 effective on driving gear , e.g. acting on power electronics, on inverter or rectifier controlled motor
• CPC Class Codes: B66B 1/308 with AC powered elevator drive
• CPC Class Codes: B66B 1/32 effective on braking devices , e.g. acting on electrically controlled brakes brake control H02P, lift brakes per se B66B5/02
• CPC Class Codes: B66B 13/22 Operation of door or gate contacts
• CPC Class Codes: B66B 5/00 Applications of checking, fault-correcting, or safety devices in elevators
• CPC Class Codes: B66B 5/0031 for safety reasons
• CPC Class Codes: B66B 5/02 responsive to abnormal operating conditions
• CPC Class Codes: B66B 5/06 electrical

Abstract

A brake controller, an elevator system and a method for performing an emergency stop are provided. The brake controller includes an input for connecting the brake controller to the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator, an output for connecting the brake controller to the electromagnet of the brake, a switch for supplying electric power from the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator via the output to the electromagnet of a brake, and also a processor with which the operation of the brake controller is controlled by producing control pulses in the control pole of the switch of the brake controller.

Claims

1. A brake controller for controlling the electromagnetic brake of an elevator, said brake controller comprising:

an input for connecting the brake controller to the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator;

an output for connecting the brake controller to an electromagnet of the brake;

a solid-state switch for supplying electric power from the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator via the output to the electromagnet of a brake; and

a processor, with which the operation of the brake controller is controlled by producing control pulses in the control pole of the switch of the brake controller.

2. The brake controller according to claim 1, wherein the brake controller comprises an input circuit for a safety signal, which safety signal can be disconnected/connected from outside the brake controller.

3. The brake controller according to claim 2, wherein the brake controller comprises brake switching logic, which is connected to the input circuit and is configured to prevent passage of the control pulses to the control pole of the switch of the brake controller when the safety signal is disconnected.

4. The brake controller according to claim 3, wherein the brake switching logic is configured to allow passage of the control pulses to the control pole of the switch of the brake controller when the safety signal is connected.

5. The brake controller according to claim 3, wherein the brake controller comprises indicator logic for forming a signal permitting startup of a run, and the indicator logic is configured to activate, and to disconnect, the signal permitting startup of a run on the basis of the status data of the brake switching logic.

6. The brake controller according to claim 3, wherein:

the signal path of the control pulses travels to the control pole of the switch of the brake controller via the brake switching logic; and

the electricity supply to the brake switching logic is arranged via the signal path of the safety signal.

7. The brake controller according to claim 3, wherein the signal path of the control pulses from the processor to the brake switching logic is arranged via an isolator.

8. The brake controller according to claim 3, wherein:

the brake switching logic comprises a bipolar or multipolar signal switch, via which the control pulses travel to the control pole of the switch of the brake controller; and

at least one pole of the signal switch is connected to the input circuit in such a way that the signal path of the control pulses through the signal switch breaks when the safety signal is disconnected.

9. The brake controller according to claim 6, wherein the electricity supply occurring via the signal path of the safety signal is configured to be disconnected by disconnecting the safety signal.

10. The brake controller according to claim 3, wherein the brake controller is implemented without any mechanical contactors.

12. The brake controller according to claim 1, wherein the brake controller comprises two outputs to be controlled with a processor independently of each other, via the first output of which electric power is supplied from the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator to the first electromagnet of a brake and via the second output electric power is supplied from the DC intermediate circuit of the frequency converter driving the hoisting machine of the elevator to the second electromagnet.

13. The brake controller according to claim 12, wherein:

the brake controller comprises two controllable switches, the first of which is configured to supply electric power to a first electromagnet of a brake and the second is configured to supply electric power to a second electromagnet of the brake;

the processor is configured to control the electricity supply to the first electromagnet by producing control pulses in the control pole of the first switch; and

the processor is configured to control the electricity supply to the second electromagnet by producing control pulses in the control pole of the second switch.

14. The brake controller according to claim 12, wherein:

the processor comprises a communications interface, via which the processor is connected to the elevator control; and

the brake controller is configured to disconnect the electricity supply to the first electromagnet but to continue the electricity supply from the DC intermediate circuit of the frequency converter to the second electromagnet after it has received from the elevator control an emergency stop request for starting an emergency stop to be performed at a reduced deceleration.

15. The brake controller according to claim 14, wherein the brake controller is configured to disconnect the electricity supply to the first and to the second electromagnet after it has received from the elevator control a signal that the deceleration of the elevator car is below a threshold value.

16. An elevator system, comprising the brake controller according to claim 1 for controlling the brake of the hoisting machine of an elevator.

17. The elevator system according to claim 16, further comprising:

a hoisting machine;

an elevator car;

a frequency converter, with which the elevator car is driven by supplying electric power to the hoisting machine;

sensors configured to monitor the safety of the elevator; and

an elevator control, which comprises an input for the data of the sensors,

wherein the elevator control is configured to form an emergency stop request for starting an emergency stop to be performed at a reduced deceleration, when the data received from the sensors indicates that the safety of the elevator is endangered.

18. The elevator system according to claim 17, wherein:

the elevator system comprises an acceleration sensor, which is connected to the elevator car;

the elevator control comprises an input for the measuring data of the acceleration sensor;

the elevator control comprises a memory, in which is recorded a threshold value of the deceleration of the elevator car;

the elevator control is configured to compare the measuring data of the acceleration sensor to the threshold value for the deceleration of the elevator car recorded in memory; and

the elevator control is configured to form a signal that the deceleration of the elevator car is below the threshold value.

11. A brake controller for controlling the electromagnetic brake of an elevator, comprising:

an input for connecting the brake controller to the DC electricity source;

an output for connecting the brake controller to the electromagnet of the brake;

a transformer, which comprises a primary circuit and a secondary circuit;

a rectifying bridge, which is connected between the secondary circuit of the transformer and the output of the brake controller;

wherein;

the input comprises a positive and a negative current conductor;

the brake controller comprises;

a high-side switch and also a low-side switch, which are connected in series with each other between the aforementioned positive and aforementioned negative current conductor;

a processor, with which the electricity supply to the electromagnet of the brake is controlled by producing control pulses in the control poles of the high-side switch and low-side switch; and

two capacitors, which are connected in series with each other between the positive and the negative current conductors; and

the primary circuit of the transformer is connected between the connection point of the high-side switch and low-side switch and the connection point of the capacitors.

19. A method for performing an emergency stop with an elevator hoisting machine driven with a frequency converter, the hoisting machine including brakes, said method comprising the steps of:

connecting one of the brakes of the hoisting machine by disconnecting the electricity supply to an electromagnet of the brake; and

keeping open the other of the brakes of the hoisting machine by continuing the electricity supply from a DC intermediate circuit of the frequency converter to the electromagnets of the other of the brakes of the hoisting machine.

20. The method according to claim 19, further comprising the steps of:

measuring the deceleration during an emergency stop of the elevator car; and

after a set period of time has passed, connecting at least one second brake of the hoisting machine after the deceleration of the elevator car is below a set threshold value.