Turbogenerator with electrical brake

• US 20020190695A1
• Filed: 02/15/2002
• Published: 12/19/2002
• Est. Priority Date: 09/08/1997
• Status: Active Grant

• Current Assignee: Capstone Turbine Corp.
• Original Assignee: Capstone Turbine Corp.
• Inventors: Wall, Simon, Pont, Guillermo, Dickey, Brian
• Granted Patent: US 6,784,565 B2
• Time in Patent Office: Days
• US Class Current: 322/17
• CPC Class Codes: F05B 2200/15 Inverse
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02P 2101/15 for wind-driven turbines
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

In an integrated turbogenerator system having an air intake for a compressor to supply combustion air to a combustor, an electric brake device such as a resistor is connected to the electrical power output of the turbogenerator and is situated in the air intake to be cooled by the stream of combustion air flowing into the intake. When load transients require unloading excess electrical power produced by the turbogenerator, the brake resistor is supplied with at least part of the excess electrical power to create heat energy and thereby heat the in-flowing combustion air to lower the combustor efficiency, turbogenerator power produced, and excess electric power to be unloaded. An algorithm may be provided for controlling the turbogenerator speed deceleration rate to maintain the brake resistor at or near a physical temperature limit.

Claims

1. An integrated turbogenerator system, comprising:

a turbine;

a compressor rotationally coupled to the turbine for rotating therewith to generate compressed air;

a combustor fluidly coupled to the compressor for combusting fuel and the compressed air therein to generate exhaust gas to drive the turbine;

a generator rotationally coupled to the turbine for rotating therewith to generate electric power; and

an electrically resistive device connected to the generator to selectively dissipate a portion of the generated power.

2. The system of claim 1, wherein the compressor comprises:

an air intake disposed in a preselected relationship to the resistive device to channel air over the resistive device and into the compressor.

3. The system of claim 2, wherein the resistive device comprises:

an electrically resistive device connected to the generator to selectively dissipate a portion of the generated power as thermal energy in the air channeled into the compressor.

4. The system of claim 1, further comprising:

a controller connected to the generator and to the resistive device to selectively supply a portion of the generated power from the generator to the resistive device.

5. The system of claim 4, wherein the generator supplies the generated power to a load, and wherein the controller selectively supplies a portion of the generated power from the generator to the resistive device in accordance with variations in the load.

6. The system of claim 5, wherein the controller controls the speed of the turbine in accordance with variations in the load.

7. The system of claim 6, wherein the controller controls the speed of the turbine in accordance with a temperature of the resistive device.

8. The system of claim 7, wherein the controller controls the speed of the turbine to maintain a temperature of the resistive device below a preselected value.

9. The system of claim 7, wherein the controller reduces the speed of the turbine in response to a reduction in the load and supplies at least a portion of any generated power in excess of the load to the resistive device, the turbine speed being reduced at a rate selected to maintain a temperature of the resistive device below a preselected value.

10. The system of claim 3, further comprising:

a controller connected to the generator and to the resistive device to selectively supply a portion of the generated power from the generator to the resistive device.

11. The system of claim 10, wherein the generator supplies the generated power to a load, and wherein the controller selectively supplies a portion of the generated power from the generator to the resistive device in accordance with variations in the load.

12. The system of claim 11, wherein the controller controls the speed of the turbine in accordance with variations in the load.

13. The system of claim 12, wherein the controller controls the speed of the turbine in accordance with a temperature of the resistive device.

14. The system of claim 13, wherein the controller controls the speed of the turbine to maintain a temperature of the resistive device below a preselected value.

15. The system of claim 13, wherein the controller reduces the speed of the turbine in response to a reduction in the load and supplies at least a portion of any generated power in excess of the load to the resistive device, the turbine speed being reduced at a rate selected to maintain a temperature of the resistive device below a preselected value.

16. The system of claim 7, wherein the compressor comprises:

an air intake disposed in a preselected relationship to the resistive device to channel air over the resistive device and into the compressor.

17. The system of claim 16, wherein the resistive device comprises:

an electrically resistive device connected to the generator to selectively dissipate a portion of the generated power as thermal energy in the air channeled into the compressor.