JOLT-FREE ELEVATOR POWER TRANSITION

• US 20170107077A1
• Filed: 03/23/2015
• Published: 04/20/2017
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Prakash, Om
• Granted Patent: US 10,144,615 B2
• Time in Patent Office: Days
• 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 5/024 where the abnormal operating condition is caused by an accident, e.g. fire
• CPC Class Codes: B66B 5/027 to permit passengers to leave an elevator car in case of failure, e.g. moving the car to a reference floor or unlocking the door

Abstract

Embodiments are directed to a converter configured to supply power to a motor of an elevator, a first power source coupled to the converter and configured to provide input power to the converter, and a second power source selectively coupled to the converter and configured to provide input power to the converter when power from the first power source is unavailable and when an elevator car of the elevator is moving, wherein a speed of the elevator car remains substantially constant when a transition in terms of the input power to the converter is made from the first power source to the second power source.

Claims

1. A system comprising:

a converter configured to supply power to a motor of an elevator;

a first power source coupled to the converter and configured to provide input power to the converter; and

a second power source selectively coupled to the converter and configured to provide input power to the converter when power from the first power source is unavailable and when an elevator car of the elevator is moving,

wherein a speed of the elevator car remains substantially constant when a transition in terms of the input power to the converter is made from the first power source to the second power source.

2. The system of claim 1, wherein the first power source comprises a three-phase power source, and wherein the second power source comprises at least one storage device.

3. The system of claim 1, wherein the second power source provides a voltage that is less than a voltage provided by the first power source.

4. The system of claim 1, wherein second power source is configured to be charged by the first power source when power from the first power source is available.

5. The system of claim 1, wherein a capacity of the second power source is sized to enable the elevator car to complete a run of requested service when power from the first power source becomes unavailable.

6. The system of claim 1, wherein a capacity of the second power source is sized to enable the elevator car to stop at a landing that is nearest the location of the elevator car when power from the first power source becomes unavailable.

7. The system of claim 1, further comprising:

a contactor configured to couple power from the second power source to the converter while the elevator car is moving and until the elevator car stops.

8. The system of claim 7, further comprising:

a second contactor configured to couple power from the second power source to the converter for a predetermined amount of time after the elevator car stops.

9. The system of claim 8, wherein the predetermined amount of time is selected to enable doors of the elevator car to open after the elevator car stops.

10. The system of claim 1, wherein the first power source provides a first voltage and the second power source provides a second voltage lower than the first voltage, the first voltage isolating the second voltage from the converter when the first voltage is available and the second voltage being coupled to the converter when the first voltage is unavailable. 11 A. method comprising:

powering, by a circuit, an elevator using power from a first power source; and

powering, by the circuit, the elevator using power from a second power source based on determining that power from the first power source is available in an amount less than a threshold,

wherein a speed of an elevator car associated with the elevator remains substantially constant when a transition in terms of input power to the elevator is made from the first power source to the second power source.

12. The method of claim 11, wherein the first power source comprises a three-phase power source, and wherein the second power source comprises at least one battery.

13. The method of claim 11, wherein the second power source provides a voltage that is less than a voltage provided by the first power source.

14. The method of claim 11, further comprising:

charging the second power source by the first power source when power from the first power source is available; and

isolating the second power source and the first power source when the power from the first power source is available in the amount less than the threshold.

15. The method of claim 11, further comprising:

sizing a capacity of the second power source to enable the elevator car to complete a run of requested service when power from the first power source is available in the amount less than the threshold.

16. The method of claim 11, further comprising:

sizing a capacity of the second power source to enable the elevator car to stop at a landing that is nearest the location of the elevator car when power from the first power source is available in the amount less than the threshold.

17. The method of claim 11, further comprising:

coupling power from the second power source to the elevator via a contactor while the elevator car is moving and until the elevator car stops.

18. The method of claim 17, further comprising:

coupling power from the second power source to the elevator via a second contactor for a predetermined amount of time after the elevator car stops.

19. The method of claim 18, further comprising:

selecting the predetermined amount of time to enable doors of the elevator car to open after the elevator car stops.

20. The method of claim 11, further comprising:

subsequent to the power from the first power source being available in the amount less than the threshold, determining, by the circuit, that the power from the first power source is available in an amount greater than a second threshold; and

based on determining that the power from the first power source is available in the amount greater than the second threshold, powering, by the circuit, the elevator using power from the first power source,

wherein the speed of the elevator car remains substantially constant when a transition in terms of input power to the elevator is made from the second power source to the first power source.

21. The method of claim 20, wherein the threshold and the second threshold are different thresholds, and wherein the second threshold is greater than the threshold.