Brake controller, elevator system and a method for performing an emergency stop with an elevator hoisting machine driven with a frequency converter

Patent metadata

Field	Value
Publication number	US-9873591-B2
Application number	US-201414533764-A
Country	US
Kind code	B2
Filing date	Nov 5, 2014
Priority date	May 31, 2012
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

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.

First claim

The invention claimed is:

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 a frequency converter driving the hoisting machine of the elevator;
an input circuit for a safety signal disconnected/connected from outside the brake controller;
two outputs for connecting the brake control to a first and second electromagnets of the brake, controlled with the processor independently of each other, via the first output, 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;
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 two outputs to the electromagnets of the brake;
a brake switching logic connected to the input circuit and configured to prevent passage of a control pulses to a control pole of the solid-state switch when the safety signal is disconnected; and
the processor, with which the operation of the brake controller is controlled by producing control pulses in the control pole of the solid-state switch of the brake controller,
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 brake controller has received from the elevator control an emergency stop request for starting an emergency stop to be performed at a reduced deceleration.

2. The brake controller according to claim 1 , 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.

3. The brake controller according to claim 1 , 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.

4. The brake controller according to claim 1 , wherein:
a 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.

5. The brake controller according to claim 1 , wherein the signal path of the control pulses from the processor to the brake switching logic is arranged via an isolator.

6. The brake controller according to claim 1 , 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.

7. The brake controller according to claim 4 , wherein the electricity supply occurring via the signal path of the safety signal is configured to be disconnected by disconnecting the safety signal.

8. The brake controller according to claim 1 , wherein the brake controller is implemented without any mechanical contactors.

9. A brake controller for controlling the electromagnetic brake of an elevator, comprising:
an input for connecting the brake controller to a DC electricity source;
an output for connecting the brake controller to an 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 conductors;
the brake controller comprises:
a high-side switch and a low-side switch, which are connected in series with each other between the positive and negative current conductors;
a processor, with which the electricity supply to the electromagnet of the brake is controlled by producing control pulses in 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 a connection point of the high-side switch and low-side switch and a connection point of the capacitors.

10. The brake controller according to claim 1 , wherein:
the brake controller comprises two controllable switches, the first of which is configured to supply electric power to the first electromagnet of the brake and the second is configured to supply electric power to the 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.

11. The brake controller according to claim 1 , wherein the brake controller is configured to disconnect the electricity supply to the first and to the second electromagnet after the brake controller has received from the elevator control a signal that the deceleration of the elevator car is below a threshold value.

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

13. The elevator system according to claim 12 , further comprising:
a hoisting machine;
an elevator car;
the 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.

14. The elevator system according to claim 13 , 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.

Assignees

• Kone Corp

Inventors

• Kattainen Ari
• Raassina Pasi
• Saarikoski Tapio
• Stolt Lauri
• Nakari Arto
• Kallioniemi Antti

Classifications

• B66B1/32 Primary

  effective on braking devices {, e.g. acting on electrically controlled brakes (brake control H02P, lift brakes per se B66B5/02)} · CPC title

• B66B5/06

  electrical · CPC title

• B66B2201/00

  Aspects of control systems of elevators · CPC title

• B66B5/0031

  for safety reasons · CPC title

• B66B5/02 Primary

  responsive to abnormal operating conditions · CPC title