Energy storage system and method for hybrid propulsion

• US 20050285554A1
• Filed: 06/28/2004
• Published: 12/29/2005
• Est. Priority Date: 06/28/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Salasoo, Lembit, Kumar, Ajith Kuttannair, Song, Dongwoo, King, Robert Dean
• Granted Patent: US 7,190,133 B2
• Time in Patent Office: Days
• US Class Current: 318/376
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• 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 hybrid propulsion system. The system comprises one or more hybrid propulsion traction drives having an electric motor operable to produce mechanical power for propulsion. A hybrid propulsion traction drive is operable to receive power from an on-board power generation system. The electric motor is operable to receive power from an energy storage unit and operable to supply power to the energy storage unit. The energy storage unit may be coupled to the electric motor via a switch.

Claims

1. A propulsion system, comprising:

an electric motor operable to produce mechanical power for propulsion and operable to generate electrical power during dynamic braking of the electric motor;

an energy storage unit operable to supply power to the electric motor to produce mechanical power for propulsion and to receive electrical power from the electric motor during dynamic braking of the electric motor; and

a switch operable to selectively couple the energy storage unit to the electric motor based on an operating parameter of the propulsion system.

2. The system as recited in claim 1, comprising a heat engine, wherein the operating parameter is output power of the heat engine, the switch being closed when the output power is within a first range of power and being opened when the output power is within a second range of power.

3. The system as recited in claim 1, comprising a first diode operable to enable power to flow from a DC link to the electric motor and the energy storage unit and to block power from flowing from the electric motor and the energy storage unit to the DC link.

4. The system as recited in claim 1, comprising a rectifier operable to enable AC power to flow from an AC link to a DC link to provide power to the electric motor.

5. The system as recited in claim 3, comprising a second diode configured to allow electric current to flow from the electric motor to a dynamic brake resistor system during dynamic braking of the electric motor.

6. The system as recited in claim 3, comprising auxiliary electrical equipment and diode circuitry, wherein the diode circuitry is operable to enable the auxiliary electrical equipment to receive power from the DC link during a first mode of operation of the propulsion system, and to enable the auxiliary electrical equipment to receive power from the electric motor during dynamic braking of the electric motor.

7. The system as recited in claim 6, wherein the diode circuitry blocks power from the electric motor from flowing to the DC link when the electric motor is providing power to the auxiliary electrical equipment.

8. The system as recited in claim 2, comprising a direct current to direct current (DC/DC) converter electrically coupled to the energy storage unit, wherein the DC/DC converter is operable to supply power to the energy storage unit during dynamic braking of the electric motor when the switch is in the open position.

9. The system as recited in claim 1, comprising a direct current to alternating current (DC/AC) inverter electrically coupled to the electric motor, wherein the DC/AC inverter is operble to convert direct current from the energy storage unit into alternating current, and operable to convert alternating current from the electric motor into direct current during dynamic braking.

10. The system as recited in claim 1, comprising a heat engine operable to provide power to the DC link.

11. The system as recited in claim 1, wherein the energy storage unit comprises a battery.

12. The system as recited in claim 1, wherein the energy storage unit comprises an ultracapacitor.

13. The system as recited in claim 1, wherein the energy storage unit comprises a flywheel.

14. The system as recited in claim 1, comprising:

an on-board power generation system operable to provide three-phase AC power;

a plurality of DC links, each DC link being operable to couple an energy storage unit to an electric motor; and

a plurality of rectifiers, each rectifier being operable to couple three-phase AC power from the on-board power generation system to a DC link.

15. A vehicle, comprising:

a hybrid propulsion traction drive operable to receive power from an on-board power generation system, the hybrid propulsion traction drive comprising;

an electric motor operable to generate electrical power during dynamic braking of the electric motor;

electrical equipment; and

electrical circuitry to enable the electrical equipment to receive electrical power from the on-board power generation system, and to receive electrical power from the electric motor during the dynamic braking of the electric motor.

16. The system as recited in claim 15, comprising an energy storage unit and a switch operable to electrically couple the energy storage unit to the electric motor.

17. The system as recited in claim 16, wherein the the electrical switch is closed to couple the energy storage system to the electric motor during a first range of vehicle power and is opened during a second range of vehicle power, wherein the second range of vehicle power is greater than the first range of vehicle power.

18. The system as recited in claim 16, comprising the on-board power generation system, wherein the power generation system provides power to a DC link.

19. The system as recited in claim 18, wherein the hybrid proplusion traction drive comprises a diode configured to allow electrical power to flow from the DC link to the electric motor and to block electrical power from flowing from the electric motor to the DC link.

20. The system as recited in claim 18, the hybrid proplusion traction drive comprises a rectifier configured to enable power to flow from an AC link into the electric motor and to block power from flowing from the electric motor to the AC link.

21. The system as recited in claim 19, wherein the switch is opened when electric power is supplied from the on-board power generation system to the electric motor.

22. The system as recited in claim 18, wherein the electrical circuitry comprises:

a diode operable to enable the electrical equipment to receive electrical power from the DC link during normal operation of the vehicle and to block power from the electric motor from flowing to the DC link during dynamic braking of the electric motor.

23. The system as recited in claim 17, comprising a direct current to direct current (DC/DC) converter electrically coupled to the energy storage unit, wherein the DC/DC converter is coupled to the energy storage unit to enable the electric motor supply power to the energy storage unit when the switch is in the open position.

24. A propulsion system for a vehicle, comprising:

a hybrid propulsion traction drive operable to receive power from an on-board power generation system, wherein the hybrid propulsion traction drive comprises;

an electric motor operable to generate electrical power during dynamic braking;

an energy storage unit; and

a switch operable to electrically couple the energy storage unit to the electric motor to enable the energy storage unit to receive electrical power from the electric motor during dynamic braking of the electric motor from a first electric motor speed; and

a direct current to direct current (DC/DC) converter operable to supply electrical power from the electrical motor to the energy storage unit during dynamic braking of the electric motor from a second electric motor speed, wherein the second electric motor speed is greater than the first electric motor speed.

25. The system as recited in claim 24, wherein the switch is closed during a first range of vehicle speed and is opened during a second range of vehicle speed vehicle, wherein the seccond range of vehicle speed is greater than the first range of vehicle speed.

26. The system as recited in claim 24, comprising the on-board power generation system, wherein the on-board power generation system is operable to supply power to a main DC link coupled to a plurality of hybrid propulsion traction drives.

27. The system as recited in claim 26, wherein each hybrid propolsion traction drive comprises:

a local DC link electrically coupled to the electric motor, and;

a first diode, wherein the diode enables electrical power to flow from the main DC link to the local DC link, and the diode blocks electrical power from flowing from the local DC link to the main DC link during dynamic braking of the electric motor.

28. The system as recited in claim 27, comprising a second diode configured to enable electrical power to flow from the DC link to a dynamic brake resistor system during dynamic braking.

29. The system as recited in claim 28, wherein the DC/DC converter receives power from the electric motor via the second diode.

30. A method of supplying power to an energy storage unit in a hybrid propulsion system for a vehicle, comprising:

electrically coupling the energy storage unit to an electric motor via an electrical switch during operation of the electric motor at a first speed to enable electric power from the electric motor to flow to the energy storage unit during dynamic braking of the electric motor at the first speed; and

electrically coupling the electric motor to the energy storage unit via a voltage converter during operation of the electric motor at a second speed, the second speed being greater than the first speed, to enable electric power from the electric motor to flow to the energy storage unit during dynamic braking of the electric motor at the second speed.

31. The method as recited in claim 30, further comprising opening the switch during operation of the electric motor at the second speed.