Power control system and method

• US 7,804,181 B2
• Filed: 04/23/2009
• Issued: 09/28/2010
• Est. Priority Date: 04/03/2006
• Status: Expired due to Fees

• Current Assignee: C E Niehoff & Company
• Original Assignee: C E Niehoff & Company
• Inventors: Becker, James
• Primary Examiner(s): GONZALEZ, JULIO C
• Application Number:
  US12/386,887
• Publication Number:
  US 20090212747A1
• Time in Patent Office: 523 Days
• Field of Search: 290/40.C, 290/40.B, 290/40.R, 322/8, 322/29, 322/44, 322/59
• US Class Current: 290/40.00C
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 29/0016 Control of angular speed of one shaft without controlling the prime mover
• CPC Class Codes: H02P 9/102 for limiting effects of transients
• CPC Class Codes: H02P 9/26 using discharge tubes or semiconductor devices H02P9/34 takes precedence
• CPC Class Codes: H02P 9/30 using semiconductor devices

Abstract

This invention discloses a power control system comprising a prime mover and a generator driven by the prime mover. A control device is coupled with the generator to ascertain a change in speed of the generator and vary an output power of the generator according to the change. The control device applies a signal to reduce the generator output power and another signal to restore the generator output power. The power control system may include a transmission, a speed converter, and/or an accessory.

Claims

1. A method for controlling a generator, said generator, coupled with one or more electrical loads, comprising a shaft driven at a speed, a generator output power controller capable of manipulating an output power of the generator, and a generator speed indicator capable of generating a signal indicative of the generator speed, said method comprising:

(a) measuring two consecutive speeds, a pre-determined time interval apart, and determining a difference between the speeds to arrive at a rate of change in speed, via a first line; and

(b) varying the output power of the generator by applying a speed-control signal to the generator output power controller, via a second line, according to said rate of change regardless of electrical power required by the one or more electrical loads.

2. The method of claim 1, further comprising measuring an output voltage of the generator, via a third line, and applying a voltage-control signal to the generator output power controller, via a fourth line, to maintain the output voltage substantially at a regulation voltage.

3. The method of claim 1, further comprising measuring an output voltage of the generator, via a third line, and applying a voltage-control signal to the generator output power controller, via the second line, to maintain the output voltage substantially at a regulation voltage and varying the regulation voltage according to said rate of change.

4. The method of claim 3, wherein the step of varying the regulation voltage comprises at least one of reducing and restoring the regulation voltage when the rate of change is above a threshold value.

5. The method of claim 4, wherein the step of varying the regulation voltage comprises reducing the regulation voltage when the algebraic sign of the rate of change is negative.

6. A control device for a generator, said generator, coupled with one or more electrical loads, comprising a shaft driven at a speed, a generator output power controller capable of manipulating an output power of the generator, and a generator speed indicator capable of generating a signal indicative of the generator speed, said control device comprising:

a processor, including a programming code operable on the processor, coupled with the generator output power controller and the generator speed indicator;

wherein said processor is configured to sense two consecutive speeds, a pre-determined time interval apart, and determine a difference between the speeds to arrive at a rate of change in speed, via a first line, and to vary the output power of the generator by applying a speed-control signal to the generator output power controller, via a second line, according to said rate of change regardless of electrical power required by the one or more electrical loads.

7. The control device of claim 6, wherein the speed-control signal comprises at least one of a phase modulated signal and step signal when the rate of change is above a threshold value.

8. The control device of claim 7, wherein the speed-control signal comprises a phase modulated signal when the algebraic sign of the rate of change is negative.

9. The control device of claim 8, wherein a duty cycle of the phase modulated signal is in proportion to the rate of change.

10. The control device of claim 9, wherein said proportionality is obtained from a look up table.

11. The control device of claim 9, wherein said proportionality is obtained from a functional relationship.

12. The control device of claim 7, wherein the speed-control signal comprises a step signal when the algebraic sign of the rate of change is positive.

13. The control device of claim 6, wherein the processor is further configured to measure an output voltage of the generator, via a third line, and apply a voltage-control signal to the generator output power controller, via a fourth line, to maintain the output voltage substantially at a regulation voltage.

14. The control device of claim 6, wherein the processor is further configured to measure an output voltage of the generator, via a third line, and apply a voltage-control signal to the generator output power controller, via the second line, to maintain the output voltage substantially at a regulation voltage, and wherein the regulation voltage is varied according to said rate of change.

15. The control device of claim 14, wherein the processor is configured to at least one of reduce and restore the regulation voltage when the rate of change is above a threshold value.

16. The control device of claim 15, wherein the processor is configured to reduce the regulation voltage when the algebraic sign of the rate of change is negative.

17. The control device of claim 15, wherein the processor is configured to restore the regulation voltage when the algebraic sign of the rate of change is positive.

18. The control device of claim 6, further comprising means for communicating system information.

19. The control device of claim 18, wherein said communication means comprises a communication terminal, coupled with a computer system, capable of transmitting/receiving a communication signal indicative of said system information.

20. The control device of claim 18, wherein said communication means comprises a light emitting diode, generating a flashing light pattern indicative of said system information.