EM57 more power

[EdAtki]

I'm planning my build around the EM57 motor initially with an 80kW inverter I got for very cheap but planning to upgrade pretty much as soon as the car is running, as such I've been reviewing the inverter options available:

• Gen 2 Leaf Inverter (Stock), 80kW, 250Nm
• Gen 2 Leaf Inverter (openinverter board), 140kW, 400Nm
• Gen 3 Leaf Inverter (Stock), 110kW, 320Nm
• Gen 3 Leaf Inverter (Stock), 160kW, 340Nm

Also worth mentioning is the unfinished openinverter board for the Gen 3, unclear what power it might make but likely more than the stock 160kW. Unfortunately development seems to have stalled on this.

My first question is which is likely to feel faster to drive between the openinverter 140kW and stock 160kW? Am I correct in thinking the 140kW would be quicker off the line but fall behind at higher speed?

Additionally I'm curious if there are any examples of the EM57 being used with other more capable inverters, most sources say that the EM57 is good for more power so I can't help but wonder how to harness that.

[eee291]

Last I checked more powerful off the shelf inverters cost 5k or more.

You can run 2 inverters in parallel like it has been done with the Toyota Prius ones

[johu]

Unfortunately development seems to have stalled on this.

Yes I assisted @glink trying to get one to run but we couldn't even complete the syncofs tuning. It was super mysterious, an inverter should just be 6 gates, 2 sensors and a fault signal. Not sure what went wrong.

You can run 2 inverters in parallel like it has been done with the Toyota Prius ones

Yes but they have to be run from a mutual control board, the PWM switching pattern must match perfectly otherwise you just short out the battery.

[Jacobsmess]

The lebowski brain was used for 300hp on a leaf motor in believe. Not sure if it was gen 1 or gen 2. The thread is here...
https://endless-sphere.com/sphere/threa ... 20possible.

[EdAtki]

The lebowski brain was used for 300hp on a leaf motor in believe. Not sure if it was gen 1 or gen 2. The thread is here...
https://endless-sphere.com/sphere/threa ... 20possible.

I believe that was with an EM61 which is supposedly even more overbuilt than the EM57, but still encouraging.

Yes but they have to be run from a mutual control board, the PWM switching pattern must match perfectly otherwise you just short out the battery.

So theoretically could the openinverter board be used to run two gen 2 inverters? Could it be as simple as:

• Connecting the output phases together in parallel obviously
• Splitting the 6 pwm signals off to the second "brainless" inverter
• ORing the desat signals from both inverters (or actually ANDing since they are active low)
• Somehow combining the signals from both sets of current sensors (summing opamp?) or just relying on one set and halving the gains

If so it seems like a reasonably straightforward set of modifications, worth exploring imo

[EdAtki]

I've been reading through old threads on the Volt/Ampera inverter. Lots of work was done on a few different openinverter logic board designs that allowed running both 600A power stages in parallel. Definitely a lot cleaner than 2 leaf inverters rigged together haha. Unfortunately information on this is pretty sparse, I can't find any info on how much power anyone managed to get out of it.

[Zieg]

Is it another option to feed it slightly higher voltage, assuming the BMS, charger, dcdc (and other systems) can handle it? I think that wouldn't help for your maximum torque, but it would sustain that torque into higher RPM and raise the peak power?