Turbogenerator with electrical brake

• US 6,784,565 B2
• Filed: 02/15/2002
• Issued: 08/31/2004
• Est. Priority Date: 09/08/1997
• Status: Expired due to Term

• Current Assignee: Capstone Turbine Corp.
• Original Assignee: Capstone Turbine Corp.
• Inventors: Wall, Simon, Pont, Guillermo, Dickey, Brian
• Primary Examiner(s): Ponomarenko, Nicholas
• Assistant Examiner(s): ADDISON, KAREN B
• Application Number:
  US10/077,121
• Publication Number:
  US 20020190695A1
• Time in Patent Office: 928 Days
• Field of Search: F02/N 1.100, 290/52, 290/7, 290/14
• US Class Current: 290/52
• 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 coupled to said turbine for rotation therewith, said compressor having an inlet portion and an outlet portion to receive air at said inlet portion and to generate compressed air at said outlet portion;

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

a generator coupled to said turbine for rotation therewith to generate electric power; and

an electrically resistive element coupled to said generator and disposed in said compressor upstream of said outlet portion in the normal direction of airflow to selectively dissipate a portion of the generated power as thermal energy in the air channeled through said compressor to said outlet portion.

2. An integrated turbogenerator according to claim 1, wherein said electrically resistive element is disposed in said inlet region of said compressor.

3. An integrated turbogenerator according to claim 2, further comprising:

an air intake disposed in said compressor to channel air over the resistive element and into the compressor.

4. An integrated turbogenerator according to claim 2, further comprising:

a filter disposed in said inlet portion of said compressor between said resistive element and said air intake to filter intake air prior to the air passing over and around said resistive element.

5. An integrated turbogenerator according to claim 2, further comprising:

a controller coupled to said generator and to said resistive element to selectively supply a portion of the generated power from said generator to said resistive element.

6. An integrated turbogenerator according to claim 5, further comprising a power converter coupled to and between said generator and said controller for supplying power from said generator to said controller.

7. An integrated turbogenerator according to claim 5, wherein said generator supplies the generated power to a load, and wherein said controller selectively supplies a portion of the generated power from said generator to said resistive element in accordance with variations in the load.

8. An integrated turbogenerator according to claim 7, wherein said controller controls the speed of said turbine in accordance with variations in the load.

9. An integrated turbogenerator according to claim 5 or 7, wherein said controller controls the speed of said turbine in accordance with a temperature of said resistive element.

10. An integrated turbogenerator according to claim 9, wherein said controller controls the speed of said turbine to maintain a temperature of said resistive element below a preselected value.

11. An integrated turbogenerator according to claim 10, wherein said controller reduces the speed of said turbine in response to a reduction in the load and supplies at least a portion of generated power in excess of the load to said resistive element, the turbine speed being reduced at a rate selected to maintain a temperature of said resistive element below a preselected value.