Found this article,
Why do I buy EXRO, why do the low prices these days don't worries me, and I believe it will be the leader in it's field in the next few years:
Since I sell electric motor and VFD in the industrial world, I think i can understand & explain EXRO Technology. I see many peoples who seems not to understand the technology properly, so here is my take on it (i'm no electrical engineer nor EXRO insider!!) Hope it will help some peoples to understand it better.
Conventional VFD or Drives have 3 ''output'' for the 3 phase motor, like the motor used in EV car. Even though battery is DC, It is converted to AC through the inverter (Inverter, VFD, drives.. all the same).
With EXRO technologies, the VFD need as many output that you have coil in the motor, not just 3 for the 3 phases.
You need a ''all leads out'' motor. Each pole (pole determine the base speed of the motor, and is directly linked to the motor torque) has many coil, and these coils need to be able to change configuration ''on the fly''. So it is not only the control board that is special with EXRO, but also the hardware. 50 coils (random number) = 50 IGBT instead of the usual 3
Ultimately EXRO technology is many inverter in one, this is the ''easy'' hardware part, and I never heard of anyone else doing this, reason being VFD come from the industrial world, where there is no reason to use battery (battery = Power limitation), usually electric motor is ''oversize'' to do the job with the desired speed range. EXRO allow to use the ''right size'' motor, not the oversize motor.
Where EXRO seems to shine, is the management of the magnetic flux in mixing ''Smartly'' the coil so the motor can overspeed (by switching from series to parallel) , and keeping the right V/Hz ratio (torque).
So there is a need to adapt from the manufacturer, but not in the space or attachement the motor frame, (they can use the same motor, but it has to be built purposely with ''All leads out'' instead of 3 leads), so mechanical drawings stay the same (except no gearbox lol), but it is the electrical wiring that has to change.
Motor OEM build the same motor, but all leads out
Replace the existing VFD with EXRO VFD Coil switching technology (that can be licensed to the existing OEM)
New wiring
Throw the gearbox in the trash...
... and voil! you have the most efficient motor with the wider speed range and torque consistent, without the gearbox compromise.
Combine this with there battery management system, and you have a turnkey powertrain/energy management solution ready for all the legacy car manufacturer (that just woke-up and have no EV planned) and their OEM supplier, having to do ''close to no modification'' to their basic stuff they just started planning.