TROLLEY INTERFACING DEVICE HAVING A PRE-CHARGING UNIT

• US 20170174087A1
• Filed: 12/18/2015
• Published: 06/22/2017
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: General Electric Company
• Inventors: Soldi, Paolo, El-Barbari, Said Farouk, Mari Curbelo, Alvaro Jorge, Schramm, Simon Herbert
• Granted Patent: US 10,300,791 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 2200/30 Trolleys
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2270/20 Inrush current reduction, i.e. avoiding high currents when connecting the battery
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 5/18 using bow-type collectors in contact with trolley wire
• CPC Class Codes: B60L 50/52 characterised by DC-motors
• CPC Class Codes: B60L 9/04 fed from dc supply lines
• CPC Class Codes: B60L 9/18 fed from dc supply lines
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A trolley interfacing device for interfacing a traction load to a voltage source is presented. The trolley interfacing device includes a first charging unit coupled in parallel to the voltage source. Further, the trolley interfacing device includes a second charging unit coupled in parallel to the traction load, where the second charging unit includes at least one inductor. Also, the trolley interfacing device includes a pre-charging unit coupled in parallel to the second charging unit and configured to pre-charge the first charging unit with a voltage across the at least one inductor prior to electrically coupling the first charging unit to the voltage source. In addition, the trolley interfacing device includes a voltage converting unit disposed between the first charging unit and the second charging unit and configured to step down a voltage provided by the voltage source to the traction load.

Claims

1. A trolley interfacing device for interfacing a traction load to a voltage source, the trolley interfacing device comprising:

a first charging unit coupled in parallel to the voltage source;

a second charging unit coupled in parallel to the traction load, wherein the second charging unit comprises at least one inductor;

a pre-charging unit coupled in parallel to the second charging unit and configured to pre-charge the first charging unit with a voltage across the at least one inductor prior to electrically coupling the first charging unit to the voltage source; and

a voltage converting unit disposed between the first charging unit and the second charging unit and configured to step down a voltage provided by the voltage source to the traction load.

2. The trolley interfacing device of claim 1, wherein the second charging unit is coupled to the traction load via a direct current (DC) bus, and wherein the DC bus is configured to electrically couple the trolley interfacing device and a power generating unit to the traction load.

3. The trolley interfacing device of claim 2, wherein the second charging unit comprises:

at least one capacitor coupled in parallel to the DC bus; and

the at least one inductor coupled in series to the DC bus.

4. The trolley interfacing device of claim 3, wherein the at least one capacitor is charged with a voltage across the DC bus.

5. The trolley interfacing device of claim 1, wherein the pre-charging unit comprises:

a plurality of electronic switches coupled in series with each other; and

a plurality of voltage distribution units, wherein each of the plurality of voltage distribution units is coupled in parallel to a corresponding electronic switch of the plurality of electronic switches.

6. The trolley interfacing device of claim 5, wherein the plurality of electronic switches is activated to energize the at least one inductor in the second charging unit.

7. The trolley interfacing device of claim 1, wherein the first charging unit comprises a first capacitor, a second capacitor, and wherein a first midpoint between the first capacitor and the second capacitor is coupled to a second midpoint of the voltage converting unit.

8. The trolley interfacing device of claim 7, wherein the plurality of electronic switches in the pre-charging unit is deactivated to provide the voltage across the at least one energized inductor to pre-charge the first capacitor and the second capacitor in the first charging unit.

9. The trolley interfacing device of claim 8, wherein the first capacitor and the second capacitor in the first charging unit are pre-charged to a first threshold value by repeatedly activating and deactivating the plurality of electronic switches.

10. The trolley interfacing device of claim 9, wherein the first threshold value is equal to or 10% higher than a voltage across the voltage source.

11. The trolley interfacing device of claim 1, further comprising at least a pair of switches coupled to the first charging unit and configured to couple the trolley interfacing device to the voltage source.

12. A method for interfacing a traction load to a voltage source, the method comprising:

decoupling a first charging unit of a trolley interfacing device from the voltage source;

activating a pre-charging unit of the trolley interfacing device to energize at least one inductor in a second charging unit of the trolley interfacing device; and

deactivating the pre-charging unit to provide a voltage across the at least one energized inductor to the first charging unit prior to electrically coupling the first charging unit to the voltage source, wherein the first charging unit is pre-charged with the provided voltage to prevent a surge current flow from the voltage source while the first charging unit is operatively coupled to the voltage source.

13. The method of claim 12, further comprising coupling the second charging unit to a DC bus for charging the second charging unit with a voltage across the DC bus.

14. The method of claim 12, further comprising pre-charging the first charging unit with the provided voltage to a voltage value equal to a first threshold value by repeatedly activating and deactivating a plurality of electronic switches in the pre-charging unit.

15. The method of claim 14, further comprising coupling the first charging unit of the trolley interfacing device to the voltage source after pre-charging the first charging unit with the voltage equal to the first threshold value.

16. A system for driving a traction load, the system comprising:

a voltage source configured to supply a direct current (DC) voltage to drive the traction load;

a trolley interfacing device disposed between the voltage source and the traction load and configured to step down the DC voltage supplied from the voltage source to the traction load, wherein the trolley interfacing device comprises;

a first charging unit coupled in parallel to the voltage source;

a second charging unit coupled in parallel to the traction load, wherein the second charging unit comprises at least one inductor;

a pre-charging unit coupled in parallel to the second charging unit and configured to pre-charge the first charging unit with a voltage across the at least one inductor prior to electrically coupling the first charging unit to the voltage source; and

a voltage converting unit disposed between the first charging unit and the second charging unit and configured to step down a voltage provided by the voltage source to the traction load.

17. The system of claim 16, wherein the pre-charging unit is configured to energize the at least one inductor in the second charging unit.

18. The system of claim 17, wherein the pre-charging unit is configured to provide the voltage across the at least one energized inductor to pre-charge the first charging unit.

19. The system of claim 18, wherein the pre-charging unit is configured to be repeatedly activated and deactivated to pre-charge the first charging unit with the provided voltage to a voltage value equal to a first threshold value.

20. A trolley interfacing kit for interfacing a traction load to a voltage source, comprising:

a pre-charging unit configured to pre-charge a first charging unit with a voltage across at least one inductor in a second charging unit prior to electrically coupling the first charging unit to the voltage source, wherein the pre-charging unit is coupled in parallel to a voltage converting unit and the second charging unit.