Systems and methods for managing a battery source associated with a microturbine power generating system

• US 6,703,719 B1
• Filed: 08/28/2002
• Issued: 03/09/2004
• Est. Priority Date: 08/28/2002
• Status: Expired due to Fees

• Current Assignee: Daniel James Warren, General Electric Company
• Original Assignee: General Electric Company
• Inventors: McConnell, Robert W.
• Primary Examiner(s): Waks, Joseph
• Application Number:
  US10/064,911
• Publication Number:
  US 20040041404A1
• Time in Patent Office: 559 Days
• Field of Search: 290/52, 363/35, 323/261
• US Class Current: 290/52
• CPC Class Codes: F01D 15/10 Adaptations for driving, or combinations with, electric generators
• CPC Class Codes: F02C 6/14 Gas-turbine plants having means for storing energy, e.g. for meeting peak loads
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02J 7/32 for charging batteries from a charging set comprising a non-electric prime mover rotating at constant speed

Abstract

A microturbine power generating system and associated method for managing a battery source associated with a microturbine power generating system is disclosed. The system and methods enable charging the battery source from the utility grid when the turbine is not running and providing load support when the microturbine engine is unable to support a transient load.

Claims

1. A microturbine power generating system, comprising:

a turbine engine for generating mechanical energy;

an electrical generator that converts the mechanical energy produced by the turbine engine into electrical energy to be supplied to a utility grid;

a battery source that provides dc power;

a voltage boosting circuit coupled to the battery source, wherein the voltage boosting circuit increases a voltage of the battery source to produces a boosted dc power operable in a startup mode and a transient load mode;

a power converter coupled to the electric generator and the voltage boosting circuit, wherein the power converter is operable to convert the boosted dc power from the voltage boosting circuit to ac power used to cause the electrical generator to turn the turbine engine in the startup mode, and to convert ac power from the electrical generator to dc power that is added to the boosted dc power from the voltage boosting circuit in the transient load mode;

a main inverter coupled to the power converter by a dc link, wherein the main inverter converts dc power on the dc link into ac power;

a transformer selectively coupled to the main inverter by an ac link, wherein the transformer couples the ac power output of the main inverter to the utility grid; and

a battery charging circuit coupled to the ac link and the battery source, wherein the charging circuit converts ac power on the ac link to dc power to charge the battery source in a charging mode when the turbine engine is not generating mechanical power.

2. The system of claim 1, wherein the battery source includes a single battery for providing the dc power.

3. The system of claim 1, wherein the voltage boosting circuit boosts the voltage of the battery source by a factor ranging between about five and fifteen.

4. The system of claim 1, wherein the voltage boosting circuit includes a pulse-width modulatable energy storage unit for storing the dc power from the ac link, and wherein the system further comprises a controller for pulse width modulating the storage unit to boost the voltage.

5. The system of claim 1, further comprising a controller for controlling the voltage boosting circuit in the transient load mode.

6. The system of claim 1, wherein the battery charging circuit includes a down chopper that is responsive to the ac power from the utility grid in a charge mode, for providing dc power at a reduced voltage to the battery source.

7. The system of claim 6, wherein the battery charging circuit further comprises a second transformer coupled to the ac link and a second power converter for converting the ac power from the second transformer to dc power, wherein the dc power output of the second power converter is reduced by the down chopper for use in charging the battery source in a charge mode.

8. The system of claim 1, further comprising a controller for controlling the battery charging circuit in the charging mode.

9. The system of claim 8, wherein the battery source is recharged as a function of battery source voltage, battery charge current and battery source temperature.

10. The system of claim 8, wherein the battery charging circuit includes a second pulse-width modulatable power averaging unit for reducing the dc power from the second power converter, and wherein the system further comprises a controller for pulse width modulating the storage unit to reduce the voltage from the utility grid.

11. The system of claim 1, wherein the ac link between the main inverter and transformer is open in the charging mode.

12. The system of claim 1, wherein operation of the voltage boosting circuit is controlled by solid state switches.

13. The system of claim 1, wherein operation of the battery charging circuit (42) is controlled by solid state switches.