Turbogenerator/motor control system

• US 6,023,135 A
• Filed: 05/18/1998
• Issued: 02/08/2000
• Est. Priority Date: 05/18/1998
• Status: Expired due to Term

• Current Assignee: Capstone Turbine Corp.
• Original Assignee: Capstone Turbine Corp.
• Inventors: Gilbreth, Mark G., Gilbreth, Charles R. Jr., Edelman, Edward C., Dickey, James Brian
• Primary Examiner(s): RODRIGUEZ, WILLIAM H
• Application Number:
  US09/080,892
• Time in Patent Office: 631 Days
• Field of Search: 318/140, 318/145, 318/147, 318/375, 318/778, 318/811, 318/471, 290/27, 290/36 R, 290/52, 290/47
• US Class Current: 318/140
• CPC Class Codes: F02C 7/268 Starting drives for the rotor , acting directly on the rotor of the gas turbine to be started
• CPC Class Codes: H02P 9/08 Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation

Abstract

A turbogenerator/motor control system having a plurality of proportional integral control loops including a fuel command control loop and a current command control loop. The exhaust gas temperature of the gas turbine of the turbogenerator/motor is maintained at a constant value with stability is achieved by varying the sampling times of the different proportional integral controls within the control loops.

Claims

1. A method of controlling a permanent magnet turbogenerator/motor comprising the steps of:

providing electrical power to the permanent magnet turbogenerator/motor through a pulse width modulated inverter to start the permanent magnet turbogenerator/motor to achieve self-sustaining operation;

disconnecting the electrical power from the pulse width modulated inverter once self-sustaining operation is achieved;

reconfiguring the pulse width modulated inverter to supply voltage from the permanent magnet turbogenerator/motor; and

maintaining the exhaust gas temperature from said permanent magnet turbogenerator/motor at a substantially constant value while supplying voltage.

2. A method of controlling a permanent magnet turbogenerator/motor comprising the steps of:

providing electrical power to the permanent magnet turbogenerator/motor through a pulse width modulated inverter to drive the permanent magnet turbogenerator/motor as a motor to accelerate the gas turbine engine of the permanent magnet turbogenerator/motor;

providing spark and fuel to the gas turbine engine of the permanent magnet turbogenerator/motor during this acceleration to achieve self-sustaining operation of the gas turbine engine;

disconnecting the electrical power from the pulse width modulated inverter once self-sustaining operation is achieved;

reconnecting the pulse width modulated inverter to the permanent magnet turbogenerator/motor through a rectifier bridge to reconfigure the pulse width modulated inverter to supply utility frequency voltage; and

maintaining the exhaust gas temperature from said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage.

3. A controller for a permanent magnet turbogenerator/motor, comprising:

a pulse width modulated inverter operably associated with said permanent magnet turbogenerator/motor;

means to provide electrical power to said permanent magnet turbogenerator/motor through said pulse width modulated inverter to start said permanent magnet turbogenerator/motor to achieve self sustaining operation;

means to disconnect the electrical power from said pulse width modulated inverter once self-sustaining operation of said permanent magnet turbogenerator/motor is achieved;

means to reconfigure said pulse width modulated inverter to supply voltage from said permanent magnet turbogenerator/motor; and

means to maintain the exhaust gas temperature from said permanent magnet turbogenerator/motor at a substantially constant value while supplying voltage.

4. A controller for a permanent magnet turbogenerator/motor having a gas turbine engine, comprising:

a pulse width modulated inverter operably associated with said permanent magnet turbogenerator/motor;

means to provide electrical power to said permanent magnet turbogenerator/motor through said pulse width modulated inverter to drive said permanent magnet turbogenerator/motor as a motor to accelerate said gas turbine engine of said permanent magnet turbogenerator/motor;

means to provide spark and fuel to said gas turbine engine of said permanent magnet turbogenerator/motor during this acceleration to achieve self sustaining operation of said gas turbine engine;

means to disconnect the electrical power from said pulse width modulated inverter and said permanent magnet turbogenerator/motor once self-sustaining operation of said gas turbine engine is achieved;

a rectifier bridge operably associated with said pulse width modulated inverter and said permanent magnet turbogenerator/motor;

means to reconnect said pulse width modulated inverter to said permanent magnet turbogenerator/motor through said rectifier bridge to reconfigure said pulse width modulated inverter to supply utility frequency voltage; and

means to maintain the exhaust gas temperature from said gas turbine engine of said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage.

5. The controller for a permanent magnet turbogenerator/motor of claim 4 wherein said means to maintain the exhaust gas temperature from said gas turbine engine of said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage includes a fuel command proportional integral control loop.

6. The controller for a permanent magnet turbogenerator/motor of claim 4 wherein said means to maintain the exhaust gas temperature from said gas turbine engine of said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage includes a current command proportional integral control loop.

7. The controller for a permanent magnet turbogenerator/motor of claim 4 wherein said means to maintain the exhaust gas temperature from said gas turbine engine of said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage includes a fuel command proportional integral control loop and a current command proportional integral control loop.

8. The controller for a permanent magnet turbogenerator/motor of claim 5 wherein said fuel command proportional integral control loop includes a power proportional integral control.

9. The controller for a permanent magnet turbogenerator/motor of claim 5 wherein said fuel command proportional integral control loop includes a speed proportional integral control.

10. The controller for a permanent magnet turbogenerator/motor of claim 5 wherein said fuel command proportional integral control loop includes a power proportional integral control and a speed proportional integral control.

11. The controller for a permanent magnet turbogenerator/motor of claim 10 wherein said speed proportional integral control has a higher sampling time than said power proportional integral control.

12. The controller for a permanent magnet turbogenerator/motor of claim 10 wherein said fuel command proportional integral control loop additionally includes a minimum DC bus voltage proportional integral control and a selector to select the highest signal from said speed proportional integral control and said minimum DC bus voltage proportional integral control.

13. The controller for a permanent magnet turbogenerator/motor of claim 6 wherein said current command proportional integral control loop includes an exhaust gas temperature proportional integral control.

14. The controller for a permanent magnet turbogenerator/motor of claim 6 wherein said current command proportional integral control loop includes a lower bus voltage proportional integral control.

15. The controller for a permanent magnet turbogenerator/motor of claim 6 wherein said current command proportional integral control loop includes an exhaust gas temperature proportional integral control and a lower bus voltage proportional integral control.

16. The controller for a permanent magnet turbogenerator/motor of claim 15 wherein said lower bus voltage proportional integral control has a higher sampling time than said exhaust gas temperature proportional integral control.

17. The controller for a permanent magnet turbogenerator/motor of claim 4 wherein said means to maintain the exhaust gas temperature from said gas turbine engine of said permanent magnet turbogenerator/motor at a substantially constant value while supplying utility frequency voltage includes a fuel command proportional integral control loop having a power proportional integral control and a speed proportional integral control, and a current command proportional integral control loop having an exhaust gas temperature proportional integral control and a lower bus voltage proportional integral control.

18. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said speed proportional integral control has a higher sampling time than said power proportional integral control.

19. The controller for a permanent magnet turbogenerator/motor of claim 18 wherein said fuel command proportional integral control loop additionally includes a minimum DC bus voltage proportional integral control and a selector to select the highest signal from said speed proportional integral control and said minimum DC bus voltage proportional integral control.

20. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said lower bus voltage proportional integral control has a higher sampling time than said exhaust gas temperature proportional integral control.

21. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said speed proportional integral control has a higher sampling time than said power proportional integral control, and said lower bus voltage proportional integral control has a higher sampling time than said exhaust gas temperature proportional integral control.

22. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said power proportional integral control has a lower sampling time than said exhaust gas temperature proportional integral control.

23. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said exhaust gas temperature proportional integral control has a lower sampling time than said speed proportional integral control.

24. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said speed proportional integral control has a lower sampling time than said lower bus voltage proportional integral control.

25. The controller for a permanent magnet turbogenerator/motor of claim 17 wherein said power proportional integral control has a lower sampling time than said exhaust gas temperature proportional integral control, said exhaust gas temperature proportional integral control has a lower sampling time than said speed proportional integral control, and said speed proportional integral control has a lower sampling time than said lower bus voltage proportional integral control.