Unthrottled engine-generator
Unthrottled engine-generator
(OP)
This question was inspired by a display of antique "hit and miss" engines. In these engines, every power stroke gets the maximum fuel/air charge, but they don't fire on every cycle. Throttled engines, of course, fire on every cycle, but they seldom use the optimum fuel/air charge. Surely the best features of each could be combined.
Are there any engines which control their output strictly via the crankshaft? I imagine this would be most easily done by varying the inducing current in the alternator. If you wanted more power, you'd temporarily reduce the alternator's output, allowing the engine to speed up. And if you wanted less power, you'd briefly increase the output, forcing the engine to slow down.
The varying electrical frequency would be cleaned up with an inverter unit like the ones in small Honda generators.
Are there any engines which control their output strictly via the crankshaft? I imagine this would be most easily done by varying the inducing current in the alternator. If you wanted more power, you'd temporarily reduce the alternator's output, allowing the engine to speed up. And if you wanted less power, you'd briefly increase the output, forcing the engine to slow down.
The varying electrical frequency would be cleaned up with an inverter unit like the ones in small Honda generators.





RE: Unthrottled engine-generator
No, I haven't seen anyone use an electric brake of whatever form on an engine for normal use, although we do use electrical dynamometers for testing.
The fuel wasteage would be horrific.
Cheers
Greg Locock
RE: Unthrottled engine-generator
It seems an obvious idea to me. The next logical step after the current crop of throttled variable-speed generators with inverters. The main problem I see is that it's a difficult balancing act. You'd have to extract just the right amount of power so that the engine neither stalled nor revved uncontrollably.
RE: Unthrottled engine-generator
Either I have missed something or this is a very odd idea.
Cheers
Greg Locock
RE: Unthrottled engine-generator
I appreaciate the dialogue, by the way.
Mike Ackerman
RE: Unthrottled engine-generator
Kind of like the way a car with automatic transmission operates- the shift program selects ratios to make good use of the motor.
Should get much better efficiency at part loads, perhaps a bit worse efficiency at full load. (maybe full load is locked at an RPM that produces the desired frequency output, so no conversion losses?)
sounds reasonable to me...
Jay Maechtlen
RE: Unthrottled engine-generator