Electronically controlled engine generator set

• US 20050116474A1
• Filed: 11/30/2004
• Published: 06/02/2005
• Est. Priority Date: 09/28/1999
• Status: Active Grant

• Current Assignee: Borealis Technical Limited (Borealis Exploration Ltd.)
• Original Assignee: Borealis Technical Limited (Borealis Exploration Ltd.)
• Inventors: Edelson, Jonathan Sidney
• Granted Patent: US 7,105,938 B2
• Time in Patent Office: Days
• US Class Current: 290/40.A
• CPC Class Codes: B60L 50/11 using DC generators and DC motors
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: H02P 2101/10 for water-driven turbines
• 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
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

An electronically controlled electrical power generator comprises a generator driven by a heat engine, operated by control means, and carrying an electrical load. Operation of the heat engine is at wide open throttle. Control over engine operation and electrical output of the generator is achieved by electronically manipulating the electric load, and/or adjusting excitation levels at the generator'"'"'s magnetic fields, so as to change engine/generator equilibrium speed. In a beneficial embodiment, the generator is powered by an energy storage unit, to temporarily act as a motor and rotate the engine when starting, and during power absorbing strokes.

Claims

1. ) A method for controlling a power output of a prime mover, comprising

a) receiving a signal indicating a changing power output requirement of the prime mover;

b) adjusting a torque load on the prime mover according to the steps;

i) increasing the torque load when said signal is indicating a decreasing power output requirement,

ii) decreasing the torque load when said signal is indicating an increasing power output requirement,

iii) equalizing the torque load on the prime mover with the power output when said signal is indicating a maintaining of power output.

2. ) The method of claim 1 wherein said step of increasing the torque load is accomplished by applying a predetermined torque load increment as many times as necessary until the prime mover achieves the required power output decrease;

and wherein said step of decreasing the torque load is accomplished by applying a predetermined torque load decrease as many times as necessary until the prime mover achieves the required power output increase.

3. ) The method of claim 1 wherein said step of receiving a signal indicating a changing power output requirement comprises sampling a difference between a power output of a prime mover and a power output requirement of the prime mover power.

4. ) The method of claim 1 wherein said step of adjusting the torque load comprises immediately applying the determined torque load.

5. ) The method of claim 1 wherein said step of adjusting the torque load comprises applying the determined torque load in a number of graduated stages of changed torque load.

6. ) The method of claim 1 wherein said step of adjusting the torque load comprises varying a transmission connecting the prime mover and a mechanical load.

7. ) The method of claim 1 wherein said step of adjusting the torque load comprises:

a) connecting an output shaft of the prime mover to a generator;

b) connecting the generator to a variable resistance electrical load; and

c) varying the resistance of the electrical load.

8. ) The method of claim 7 further comprising the step of:

producing an excess electrical power by the generator and storing said excess.

9. ) The method of claim 8 wherein said step of producing an excess electrical power occurs during a power-producing stroke of the prime mover or during periods of reducing prime mover speed.

10. ) The method of claim 7 further comprising the step of sourcing extra electrical power during a non-power producing stroke of the prime mover and during periods of increasing prime mover speed.

11. ) The method of claim 10 further comprising the steps of:

a) detecting said non-power producing stroke; and

b) reducing the torque load during said non-power producing stroke.

12. ) The method of claim 11 wherein said detecting step comprises a detecting step selected from the group consisting of:

sensing a rotary angle of the prime mover, and sensing a piston position of the prime mover.

13. ) The method of claim 7 wherein the step of varying the resistance of the electrical load comprises the steps of:

a) establishing a threshold voltage;

b) substantially preventing a current flow to the electrical load when an output voltage of said generator is below said threshold voltage, and allowing a current to flow to the electrical load when an output voltage of said generator is above said threshold voltage;

c) adjusting the threshold voltage to increase or to decrease the electrical current flow to the electrical load.

14. ) The method of claim 13 wherein said of preventing a current to flow comprises steeply decreasing the current flow to the electrical load substantially immediately following any drop in output voltage.

15. ) The method of claim 13 further comprising the steps of

a) producing electrical power by means of an auxiliary power supply;

b) applying said electrical power to the generator when the output voltage of the generator falls below said threshold voltage.

16. ) The method of claim 15 wherein a current versus voltage characteristic of the generator causes an automatic transition of generator to motor action.

17. ) The method of claim 7 further comprising the step of starting the prime-mover and generator, where the generator is of the type that can operate as a motor, comprising the steps:

v) receiving a command to start system,

w) synthesizing electricity of suitable voltage and current characteristics from an auxiliary energy supply to enable the generator to rotate the prime mover, and providing a fuel source and associated starting requirements to said prime mover.

18. ) A method for controlling a heat engine generator combination comprising the steps:

a) operating the heat engine in a wide open throttle condition;

b) controlling a torque/speed characteristic of the generator;

whereby a power output of the heat engine generator combination is regulated by controlling the number of piston strokes per second.

19. ) The method of claim 18 wherein the step of controlling the torque/speed comprises a controlling step selected from the group consisting of:

controlling generator excitation, controlling a voltage/current characteristic of a load and controlling a frequency characteristic of a load.

20. ) The method of claim 18 wherein the step of controlling the torque/speed characteristic comprises synchronizing the torque/speed characteristic of the generator with a cyclic torque change of output of the heat engine.

21. ) A method for controlling an unthrottled heat engine—

generator combination to produce a desired power output, comprising;

a) determining an engine torque produced when the engine operates at a power output equal to the desired power output; and

b) controlling one or more electrical characteristics of at least one of the generator and an electrical load connected to the generator so that a torque load applied to the engine is equal to the engine torque determined in step a).

22. ) The method according to claim 21, wherein the generator is an AC generator having a variable excitation frequency and wherein step b) comprises varying an excitation frequency of the generator.

23. ) The method according to claim 21 wherein the generator is an induction generator and wherein step b) comprises controlling a quadrature current of the generator.

24. ) The method according to claim 23 wherein a ratio of a current to a voltage produced by the generator is high, whereby when a stroke of the engine is a non-power generating stroke and the generator voltage decreases, the generator current significantly decreases.

25. ) The method according to claim 24 further comprising the step of:

providing current to the generator from an energy source when the voltage decreases below a threshold voltage.

26. ) The method according to claim 25 further comprising the generator supplying output power to the energy source and the load drawing power from the energy source.

27. ) The method according to claim 21 wherein the generator is a DC generator and the load is a power electronic load, wherein step b) comprises:

i) establishing a threshold voltage for the power electronic load below which little or no current can flow;

ii) controlling the current flowing through the power electronic load to be in fixed proportion according to the degree to which the generator voltage is above the threshold, and

iii) varying the threshold voltage.

28. ) The method according to claim 27 further comprising connecting an energy source to the power electronic load, and wherein the generator is operable as a motor, further comprising:

providing current to the generator from the power source via the power electronic load according to the degree to which the generator voltage is below the threshold voltage.

29. ) The method according to claim 21 wherein the generator is an AC generator and wherein the load is a power electronic load, wherein step b) comprises:

i) establishing a threshold frequency of the power electronic load below which little or no current can flow;

ii) controlling the current flowing through the power electronic load to be in fixed proportion according to the degree to which the generator voltage is above the threshold, and

iii) varying the threshold frequency.

30. ) The method according to claim 29 further comprising connecting an energy source to the power electronic load, and wherein the generator is operable as a motor, further comprising:

providing current to the generator from the power source via the power electronic load according to the degree to which the generator voltage is below the threshold voltage.

31. ) A method for regulating the cyclic speed variations of an engine, comprising:

connecting said engine to a generator/motor having a very high torque versus speed relationship, said generator/motor connected to a current source and a load, and;

i) generating electrical power for said load during power producing strokes of said engine,

ii) drawing electrical power from said source during power absorbing strokes of said engine,

whereby substantially maintaining the speed of the engine.