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I think this is how some Diesel-electric locomotives are built, with Diesel engines creating electricity for electric motors, running the ICE at constant speed

I think this is how some Diesel-electric locomotives are built, with Diesel engines creating electricity for electric motors, running the ICE at constant speed and minimum transmission (not sure a reduction is needed, probably not). Looks like solid engineering for the cases when electrification is not possible for various reasons.

whaleofatw2022 2y ago
Diesel electrics can be big enough and with long enough expected lifetimes to go 'all out', I think in some ways they can get closer to CCGT as far as efficiency. Where the challenge comes for smaller vehicles, is the more power you are trying to give, the more you have to build everything up; not just the engine but whatever that engine is inputting into, also trains have somewhat more predictable speed profiles over a trip vs a car. This is why some manufacturers have vehicles that are PHEVS but really BEVs with an 'oh crap' extender that can struggle to keep up a good grade. I gotta give TRD/Toyota/Ford credit, the HSD style drive train does work around a lot of this stuff for PHEVS; in lockup mode you have a 1:1 ratio with minimal losses and at that point it's up to the ability of the engine to adjust profile. Works very well in practice, and far simpler than the setups of others.
Animats 2y ago
Diesel-electric locomotives were the first vehicles to get really good motor control. In what are called "AC" locomotives, the wheel motors are 3 phase variable-frequency AC motors. The power train is Diesel engine -> generator -> really big MOSFETs -> synchronous 3-phase motors. Each motor is separately controlled and they are run as synchronized servomotors, to prevent wheel slip. When multiple locomotives are coupled together, they synchronize at the wheel level. The effect is almost 2x more traction than older technology, which means fewer locomotives per train. Automotive motor controllers now use similar technology, but the locomotives had it first.

whaleofatw2022 2y ago

Diesel electrics can be big enough and with long enough expected lifetimes to go 'all out', I think in some ways they can get closer to CCGT as far as efficiency. Where the challenge comes for smaller vehicles, is the more power you are trying to give, the more you have to build everything up; not just the engine but whatever that engine is inputting into, also trains have somewhat more predictable speed profiles over a trip vs a car. This is why some manufacturers have vehicles that are PHEVS but really BEVs with an 'oh crap' extender that can struggle to keep up a good grade. I gotta give TRD/Toyota/Ford credit, the HSD style drive train does work around a lot of this stuff for PHEVS; in lockup mode you have a 1:1 ratio with minimal losses and at that point it's up to the ability of the engine to adjust profile. Works very well in practice, and far simpler than the setups of others.

Animats 2y ago

Diesel-electric locomotives were the first vehicles to get really good motor control. In what are called "AC" locomotives, the wheel motors are 3 phase variable-frequency AC motors. The power train is Diesel engine -> generator -> really big MOSFETs -> synchronous 3-phase motors. Each motor is separately controlled and they are run as synchronized servomotors, to prevent wheel slip. When multiple locomotives are coupled together, they synchronize at the wheel level. The effect is almost 2x more traction than older technology, which means fewer locomotives per train. Automotive motor controllers now use similar technology, but the locomotives had it first.