Hybrid power system characterization
A system includes a torque sensor; and a hybrid power system. The hybrid power sensor includes a frame; an engine mounted on the frame; and a generator, the generator including: a generator rotor mechanically coupled to a shaft of the engine; and a generator stator coupled to the frame by the torque sensor. The torque sensor is configured to measure a torque on the generator stator.
1. A system comprising:
a torque sensor; and
a hybrid power system comprising:
a frame;
an engine mounted on the frame;
a generator, the generator including:
a generator rotor mechanically coupled to a shaft of the engine; and
a generator stator coupled to the frame by the torque sensor;
wherein the torque sensor is configured to measure a value of a torque on the generator stator applied by the engine.
2. The system of claim 1 , comprising a device configured to measure an electrical output of the generator.
3. The system of claim 2 , comprising a computing system configured to:
determine a mechanical output power of the engine based on the measured value of the torque and a number of revolutions per minute of the engine; and
map the mechanical output power of the engine to the electrical output of the generator.
4. The system of claim 1 , comprising an electric load electrically connected to the generator.
5. The system of claim 4 , wherein the electric load comprises a time-varying electric load.
6. The system of claim 4 , wherein the electric load comprises an electric motor.
7. The system of claim 6 , wherein the electric load comprises the electric motor and a propeller driven by the electric motor.
8. The system of claim 7 , wherein the electric motor comprises a brushless direct current motor.
9. The system of claim 8 , comprising a control system configured to control a speed of the electric motor.
10. The system of claim 4 , wherein the electric load is selected based on a characteristic of an unmanned aerial vehicle.
11. The system of claim 1 , wherein the engine comprises a reciprocating piston engine.
12. The system of claim 1 , wherein the generator comprises a permanent magnet multi-pole generator.
13. The system of claim 1 , wherein the generator produces an alternating current output, and
comprising a rectifier configured to convert the alternating current output from the generator into direct current.
14. The system of claim 1 , wherein the generator rotor is mechanically coupled to the shaft of the engine by a flexible coupling.
15. The system of claim 14 , wherein the flexible coupling comprises a polyurethane coupling.
16. The system of claim 1 , comprising an unmanned aerial vehicle, wherein the hybrid power system is mounted on the unmanned aerial vehicle.
17. The system of claim 1 , wherein the generator stator is coupled to the frame in a substantially fixed orientation by the torque sensor.
18. The system of claim 1 , wherein the torque sensor comprises a strain sensor.
19. A method comprising:
operating a hybrid power system comprising:
a frame;
an engine mounted on the frame;
a generator, the generator including:
a generator rotor mechanically coupled to a shaft of the engine; and
a generator stator coupled to the frame; and
during operation of the hybrid power system, measuring
(i) a value of a torque on the generator stator applied by the engine using a torque sensor coupling the generator stator to the frame and (ii) an electrical output of the generator.
20. The method of claim 19 , comprising determining a mechanical output power of the engine based on the measured value of the torque and a number of revolutions per minute of the engine.
21. The method of claim 20 , comprising mapping the mechanical output power of the engine to the electrical output of the generator.
22. The method of claim 21 , comprising varying an electric load electrically connected to the generator.
23. The method of claim 22 , comprising mapping the mechanical output power of the engine to the electrical output of the generator as a function of the varying electric load.
24. The method of claim 22 , wherein the electric load comprises an electric motor and a propeller driven by the electric motor.
25. The method of claim 24 , wherein varying the electric load comprises controlling a speed of the electric motor.
26. The method of claim 21 , comprising identifying a particular number of revolutions per minute of the engine at which the mechanical output power of the engine is a maximum.
27. The method of claim 26 , comprising controlling operation of the generator based on the particular number of revolutions per minute at which the mechanical output power is a maximum.
28. The method of claim 21 , comprising determining an indicator of an efficiency of the engine.
29. The method of claim 19 , wherein the generator stator is coupled to the frame in a substantially fixed orientation by the torque sensor.
30. The method of claim 19 , comprising measuring the value of the torque using a strain sensor.