REGENERATIVE POWER CONTROL FOR PASSENGER CONVEYORS

• US 20130270061A1
• Filed: 12/17/2010
• Published: 10/17/2013
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Ma, GuangHua
• Granted Patent: US 8,973,731 B2
• Time in Patent Office: Days
• US Class Current: 198/330
• CPC Class Codes: B66B 23/02 Driving gear
• CPC Class Codes: B66B 25/00 Control of escalators or moving walkways walkways of variable speed type B66B21/12; handrails of variable speed type B66B23/26; of general application G05
• CPC Class Codes: B66B 25/003 Methods or algorithms therefor
• CPC Class Codes: Y02B 50/00 Energy efficient technologies in elevators, escalators and moving walkways, e.g. energy saving or recuperation technologies

Abstract

An exemplary device for controlling power associated with a passenger conveyor motor includes a regenerative drive that is configured to facilitate providing electricity generated by the motor to a power source when the passenger conveyor is moving. The controller determines when an operating condition of the regenerative drive is outside of a desired range and responsively prevents the regenerative drive from facilitating providing the electricity to the power source.

Claims

1. A device for controlling power associated with a passenger conveyor motor, comprising:

a regenerative drive that is configured to facilitate providing electricity generated by the motor to a power source when the passenger conveyor is moving; and

a controller that determines when an operating condition of the regenerative drive is outside of a desired range and responsively prevents the regenerative drive from facilitating providing the electricity to the power source.

2. The device of claim 1, wherein the operating condition comprises current and the controller determines when the current exceeds a threshold.

3. The device of claim 1, wherein the operating condition comprises temperature and the controller determines when the temperature exceeds a threshold.

4. The device of claim 3, comprising a heat sink associated with the regenerative drive and wherein the controller determines the temperature at the heat sink.

5. The device of claim 1, comprising a bypass switch between the regenerative drive and the power source and wherein the controller controls the bypass switch to permit or prevent the regenerative drive from facilitating providing electricity to the power source.

6. The device of claim 1, wherein the controller controls whether the regenerative drive facilitates providing the electricity to the power source dependent on a direction of movement of the passenger conveyor.

7. The device of claim 6, wherein the controller permits the regenerative drive to facilitate providing the electricity to the power source when the direction of movement is down and the operating condition is within the desired range.

8. The device of claim 7, wherein the desired range of the operating condition corresponds to a load on the passenger conveyor being between about 30% and about 70% of a full rated load for the conveyor.

9. The device of claim 6, wherein the controller permits the regenerative drive to be connected between the power source and the motor during a start up procedure when the direction of movement is up and the passenger conveyor is moving at a speed below a selected threshold speed and the controller otherwise disconnects the regenerative drive from the power source when the direction of movement is up.

10. A method of controlling power associated with a passenger conveyor motor, comprising the steps of:

generating electricity from the motor when the passenger conveyor is moving;

facilitating providing the electricity to a power source through a regenerative drive; and

determining when an operating condition of the regenerative drive is outside of a desired range and responsively preventing the regenerative drive from facilitating providing the electricity to the power source.

11. The method of claim 10, wherein the operating condition comprises current and the method comprises determining when the current exceeds a threshold.

12. The method of claim 10, wherein the operating condition comprises temperature and the method comprises determining when the temperature exceeds a threshold.

13. The method of claim 12, wherein there is a heat sink associated with the regenerative drive and the method comprises detecting the temperature at the heat sink.

14. The method of claim 10, wherein there is a bypass switch between the regenerative drive and the power source and the method comprises controlling the bypass switch to permit or prevent the regenerative drive from facilitating providing the electricity to the power source.

15. The method of claim 10, comprising controlling whether the regenerative drive facilitates providing the electricity to the power source dependent on a direction of movement of the passenger conveyor.

16. The method of claim 15, comprising permitting the regenerative drive to facilitate providing the electricity to the power source when the direction of movement is down and the operating condition is within the desired range.

17. The method of claim 16, wherein the desired range of the operating condition corresponds to a load on the passenger conveyor being between about 30% and about 70% of a full rated load for the conveyor.

18. The method of claim 15, comprising

permitting the regenerative drive to be connected between the power source and the motor during a start up procedure when the direction of movement is up and the passenger conveyor is moving at a speed below a selected threshold speed;

and

otherwise disconnecting the regenerative drive from the power source when the direction of movement is up.

19. A passenger conveyor, comprising:

a plurality of steps;

a motor associated with the steps for selectively moving the steps;

a regenerative drive configured to facilitate providing electricity generated by the motor to a power source when the steps are moving; and

a controller that determines when at least one of a current or a temperature of the regenerative drive is outside of a desired range and responsively prevents the regenerative drive from facilitating providing the electricity to the power source.

20. The passenger conveyor of claim 20, comprising a bypass switch between the regenerative drive and the power source and wherein the controller controls the bypass switch to permit or prevent the regenerative drive from facilitating providing electricity to the power source.