Elevator

Patent metadata

Field	Value
Publication number	US-12098056-B2
Application number	US-201916449670-A
Country	US
Kind code	B2
Filing date	Jun 24, 2019
Priority date	Jul 4, 2018
Publication date	Sep 24, 2024
Grant date	Sep 24, 2024

Abstract

An elevator may include an elevator motor driving at least one elevator car in a hoisting path, which elevator motor is driven via a frequency converter controlled by a control device of the elevator. The frequency converter includes a rectifier bridge and an inverter bridge and a DC link in-between. The elevator further includes at least one elevator brake acting on a brake element rotating with the rotor of the elevator motor, which elevator brake is driven via a brake drive which is connected to the DC link of the frequency converter an comprises a DC/DC converter having its primary side connected to the DC link and its secondary side connected to a brake circuit comprising at least one brake coil of the elevator brake and at least one rectifying element. In the primary side of the DC/DC converter, a first semiconductor switch is connected which is controlled by the control device of the elevator. In the brake circuit a second semiconductor switch is connected which is also controlled by the control device of the elevator, whereby an earth fault indication circuit is connected between the brake circuit and earth. The earth fault indication circuit includes an transmitting part of an opto-coupler, which opto-coupler has its sensor part connected to an earth fault transmission circuit connected to the control device of the elevator. The control device is configured to control the first and/or second semiconductor switch depending on the signal of the earth fault transmission circuit.

First claim

The invention claimed is:

1. A brake drive of an elevator the brake drive comprising:
a galvanically separating link component having a primary side and a secondary side, the primary side connected to a DC link between a rectifier bridge and an inverter bridge;
a brake circuit connected to the secondary side of the galvanically separating link component, the brake circuit including at least one brake coil of an elevator brake and at least one rectifying element;
a first semiconductor switch connected to the primary side of the galvanically separating link component;
a second semiconductor switch;
an earth fault indication circuit connected between the brake circuit and earth, the earth fault indication circuit including a transmitting part and a receiving part;
an earth fault transmission circuit configured to generate an earth fault signal in response to the earth fault indication circuit indicating an earth fault in the brake circuit; and
a control device configured to determine if the earth fault is present in brake circuit by first switching on at least the first semiconductor switch to supply power to the secondary side of the galvanically separating link component, second switching off the second semiconductor switch for at least a set period of time, and determining whether the earth fault is present based on whether the earth fault signal of the earth fault transmission circuit is received from the earth fault transmission circuit.

2. The brake drive of claim 1 , wherein the galvanically separating link component is a DC/DC converter.

3. A brake drive of an elevator the brake drive comprising:
a galvanically separating link component having a primary side and a secondary side, the primary side connected to a DC link between a rectifier bridge and an inverter bridge;
a brake circuit connected to the secondary side of the galvanically separating link component, the brake circuit including at least one brake coil of an elevator brake and at least one rectifying element;
a first semiconductor switch connected to the primary side of the galvanically separating link component;
a second semiconductor switch;
an earth fault indication circuit connected between the brake circuit and earth, the earth fault indication circuit including a transmitting part and a receiving part;
an earth fault transmission circuit configured to generate an earth fault signal in response to the earth fault indication circuit indicating an earth fault in the brake circuit; and
a control device configured to control one or more of the first semiconductor switch and the second semiconductor switch by switching on/off the first semiconductor switch and the second semiconductor switch based on the earth fault signal of the earth fault transmission circuit.

4. The brake drive of claim 1 , wherein the earth fault indication circuit comprises:
an opto-coupler.

5. The brake drive of claim 4 , wherein the transmitting part of the opto-coupler is a LED.

6. The brake drive of claim 1 , wherein the earth fault indication circuit comprises:
a diode in series with the transmitting part.

7. The brake drive of claim 1 , wherein the earth fault indication circuit comprises:
a resistor in series with the transmitting part, a resistance of the resistor being greater than a resistance of the brake coil.

8. The brake drive of claim 7 , wherein the resistance of the resistor is at least ten times the resistance of the brake coil.

9. The brake drive of claim 1 , wherein the first semiconductor switch is PWM controlled.

10. The brake drive of claim 1 , wherein the brake circuit further comprises:
a varistor connected in parallel to the brake coil.

11. The brake drive of claim 10 , wherein the brake circuit further comprises:
a diode is connected in series with the varistor.

12. The brake drive of claim 1 , wherein the at least one rectifying element comprises:
one or more of a diode and a smoothing capacitor.

13. The brake drive of claim 1 , wherein the control device is connected to a location sensor of an elevator car in an elevator shaft, and the control device comprises:
a delay circuit configured to, in response to the earth fault signal from the earth fault transmission circuit, delay switching off of the first semiconductor switch and the second semiconductor switch until the elevator car reaches a door zone of the elevator.

14. The brake drive of claim 1 , wherein the control device is configured to prevent a re-start of the elevator in response to the earth fault signal from the earth fault transmission circuit.

15. A method for operating a brake drive of an elevator, the brake drive including a galvanically separating link component having a primary side and a secondary side, the primary side connected to a DC link between a rectifier bridge and an inverter bridge, a brake circuit connected to the secondary side of the galvanically separating link component, the brake circuit including at least one brake coil of an elevator brake and at least one rectifying element, a first semiconductor switch connected to the primary side of the galvanically separating link component; a second semiconductor switch, an earth fault indication circuit connected between the brake circuit and earth, the earth fault indication circuit including a transmitting part and a receiving part, an earth fault transmission circuit and a control device configured to control one or more of the first semiconductor switch and the second semiconductor switch, the method comprising:
first switching on at least the first semiconductor switch to supply power to the secondary side of the galvanically separating link component;
second switching off the second semiconductor switch for at least a set period of time;
determining whether an earth fault is present in the brake circuit based on whether an earth fault signal is received from the earth fault transmission circuit; and
selectively driving an elevator car to a next landing after receiving the earth fault signal from the earth fault transmission circuit.

16. The method according to claim 15 , further comprising:
preventing a re-start of the elevator car after driving the elevator car to the next landing.

17. The method according to claim 15 , further comprising:
third switching on the second semiconductor switch in response to the determining that the earth fault is not present, wherein
the selectively driving the elevator car includes switching off the first semiconductor switch to prevent the elevator car from starting, in response to determining that the earth fault is present when the elevator car is stopped at a current landing.

18. The method according to claim 15 , wherein the first switching includes switching on both the first semiconductor switch and the second semiconductor switch, the second switching switches off the second semiconductor switch for the set period of time shorter than a time to engage the elevator brake, and the method further comprises:
third switching the second semiconductor switch back on irrespective of whether the earth fault is present before the elevator brake engages such that the elevator car is controlled to travel to its a destination.

19. The brake drive of claim 1 , wherein the control device is further configured to,
drive an elevator car to a next landing, after receiving the earth fault signal from the earth fault transmission circuit, and
switch off the first semiconductor switch to prevent the elevator car from starting, after driving the elevator car to the next land

Assignees

• Kone Corp

Inventors

• Nikander Juhamatti

Classifications

• H02P3/24

  by applying DC to the motor · CPC title

• B66B5/02

  responsive to abnormal operating conditions · CPC title

• B66B5/00 Primary

  Applications of checking, fault-correcting, or safety devices in elevators · CPC title

• B66B1/3492

  Position or motion detectors or driving means for the detector (B66B1/40, B66B1/50 take precedence; length measuring G01B; speed measuring G01P) · CPC title

• 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