Regeneration efficiency leaf gen2

[Nautilus]

Hi every one
Can someone tell me how efficient regen is on leaf 2 engine and inverter ?
Ex if i spin the leaf with a known power let's say 40 kw and how many kw will i get back in regen?
Thankful for help

[arber333]

Hi every one
Can someone tell me how efficient regen is on leaf 2 engine and inverter ?
Ex if i spin the leaf with a known power let's say 40 kw and how many kw will i get back in regen?
Thankful for help

Are you a bot?

At what voltage is that 40kW used?
40Kw will certainly push your 1t car to 100km/h and then some. At that speed you can get 30kW back downhill easily... however not for long. At that power you will drain speed too fast and power will drop as well. It all depends on how you can sustain your speed under regen.

I think you can get maybe 30% return in city stopngo and maybe 25% in the hills outside the city. Just dont forget you need power to climb the hill as well.

[Nautilus]

Hi no i am lot a bot:)

I want too use one leaf engine to build a dc generator and that seems too have been done but what i dont find is how efficient leaf engine is when regen! In normal motor operation at 2000rpm th seams to be around 94%

Regards

[johu]

I don't know of any difference between negative and positive torque. So if you found it to be 94% efficient driving in that operating point it will also be 94% efficient regenning

[Nautilus]

Thank you
That was what i thought:)
I have read that some people have seen hi regen numbers but never the full raiting of the engine is that a limitation in the inverter or inte battery pack ?

I have
60 something kw in the batteris but i also have 3 leaf engine doing other stuff like bowtrusters and take me home engine if the main engine fails so i want to get 80kw from the leaf used as generator is that possible

[johu]

Are you running with the stock logic board? It receives a BMS charge power limit over CAN, see here: https://github.com/jsphuebner/stm32-car ... s.cpp#L113

Don't know if there are other limits. Maybe the drop-in OI board is for you? https://openinverter.org/shop/index.php ... duct_id=57

[arber333]

....
I have
60 something kw in the batteris but i also have 3 leaf engine doing other stuff like bowtrusters and take me home engine if the main engine fails so i want to get 80kw from the leaf used as generator is that possible

You still didnt said what voltage you intend to run the motor at. It depends a lot. 2000rpm input will require some kind of pulley system to increase motor RPM for better efficiency. I think at 2000 motor rpm you would get at best 90% with less torque. At 4000 motor rpm you would get 95% and 200Nm torque available. You can calculate power input mechanicaly...

I would imagine regen quadrant would behave the same...
viewtopic.php?t=3259

[Zieg]

Oh that's interesting. Mine tops out around 4kW. Assumed that was the most it could do. D: How much are others getting?


Edit: i just checked my params, looks like I have idcmin set to -18 amps for some reason. That's still more than I'm actually seeing going to the battery but obviously I'll have to change that first and see what happens.

[Jacobsmess]

There was a post o here of someone using a smart motor and leaf as a generator and getting 30kw in regen once setup properly with the OI inverter board

[Jacobsmess]

Here
viewtopic.php?p=53039#p53039

[arber333]

Oh that's interesting. Mine tops out around 4kW. Assumed that was the most it could do. D: How much are others getting?

Why that small?
I am using gen1 motor with Lebowski brain and Volt inverter and i can get 110kW from the motor in drive. In regen i have seen 115A go back to battery which was 96S. That was down a hill on highway 140km/h. Didnt last long though as it bled energy quickly.
However i did notice there was different torque distribution at speeds above FW region. I got 15A more when trying to keep throtle at 0 torque request...

[jrbe]

A stock 2019 leaf gets about 30kw of regen. That doesn't mean it's the maximum, just what Nissan does.
The stock motor will do 160kw in forward acceleration for short bursts in the 2018 plus models. Same motor besides the really early ones. You'll have to watch heat and magnet heat when pushing it constantly.

[Nautilus]

Hi yes i have read the smart engine generator tread and that is good news i am using the open inverter bord an the other engines so this will be the same:)

I need very close to 500v and the constant full output is only in rare occasions! The normal is probably 30-40kw for 1.5 h to charge the bank that allows supply ac power to the hole ship!

I have to live whit then 90% efficiency then, i want direkt drive pulley system is never a good idea you nead extra shafts extra berings and i think that will decrease the efficiency more then 5 % and give more maintenance and initial work!

Thanks for all the answers