continuous regen as ac generator

[oelbrenner]

Im building a 4x4 land rover ( range rover p38 ), and the back of the transfer case ( a land rover LT230 ) has a provision for a PTO attachment.

I plan to mount a small 35 - 65 HP AC motor onto the back of this transfer case and hook it up to the PTO spline.

the PTO input and the transmission input are the same physical shaft, so engine/transmission and PTO are directly connected.

take a look at the attached diagram, I have have 4 modes I am thinking I can run in:

BEV:
normal battery electric vehicle mode, power from batteries, regen braking etc.
the the gearbox attached to ICE engine will be in neutral.
in this mode the ICE engine can be not be running, AC motor providing power to transfer case and wheels

ICE:
typical ICE configuration, engine drives transmission, which drives transfer case, and power transmitted to wheels.
in this mode, the AC motor shaft will be turning, but no electrical load of any kind.


Hybrid:
typical Hybrid configuration, ICE engine provides *most* of the power, AC motor can contribute power also.


Generator:
this is the one mode where I have a question...
this setup would be running the ICE engine at some pre-determined RPM
transmitting power thru the gearbox with some pre-determined gear selected
the clutch engaged, which in turn would be driving the AC motor.
The transfer case would be in "neutral" so this power would . *not* be transmitted to the wheels.

I would want to be able to put the AC motor in MAX regen where it would act like a generator.

if I connected a large AC load to this output:

1. would this be a configuration that could be run for extended periods of time ?
use case would be using it like a whole house generator would be used, running a 20 - 50 amp 240V AC load for potentially hours and
hours on end.

2. what would be a way to control this configuration so that I can deal with the possibility of fully charged battery pack, and low AC load
( need to shed current / remove regen load from AC motor )

3. is this even a good idea in the first place ?


a couple of things to note, I have not selected any of the electrical parts as of yet.. batteries, motor, inverters etc.. all a clean slate

[johu]

1. I think it all comes down to cooling. If you can cool inverter & motor sufficiently during stand still you can run continously
2. The inverter has a built-in, adjustable max voltage limit upon which it will reduce regen. In addition it has a BMS pin that you can program to limit regen as well
3. I don't know, I guess you'll find out

[sfk]

Cool project! I have a couple of P38s and wondered about the potential to convert to EV for farm utility use.
Do you know if the auto transmission also has a covered PTO or is it just the manual gearboxes from the diesel?

[oelbrenner]

1. I think it all comes down to cooling. If you can cool inverter & motor sufficiently during stand still you can run continously
2. The inverter has a built-in, adjustable max voltage limit upon which it will reduce regen. In addition it has a BMS pin that you can program to limit regen as well
3. I don't know, I guess you'll find out

thanks very much !

I think I will most likely use a complete system out of a car, like the nissan leaf setup, and just build in additional capacity with the cooling system.. higher flow coolant pumps, larger radiator etc..

[oelbrenner]

Cool project! I have a couple of P38s and wondered about the potential to convert to EV for farm utility use.
Do you know if the auto transmission also has a covered PTO or is it just the manual gearboxes from the diesel?

the engine/transmission/transfer case im using is a bit of a mashup.

engine is a mercedes OM603 inline 6 diesel
transmission is a 6-speed manual from a mercedes CLK230
transfer case is from a Land Rover Discovery ( LT230 locking center diff )

the standard range rover P38 uses the borg warner transfer case, which does not have a PTO provision, and runs a fluid coupling for front/rear torque distribution.

[PriusGuy]

I remember an old timer showing me a generator he had under the hood of his car. It was some kind of an aftermarket add-on device. It looked like a big heavy electric motor with a pulley on it. It ran off of one of the belts and basically had a 120 volt outlet right on the back. As long as the engine was running at about the right speed it would crank out the power indefinitely.