View Single Post
Old 11-16-2014, 12:16 PM   #1315 (permalink)
P-hack
Master EcoModder
 
P-hack's Avatar
 
Join Date: Oct 2012
Location: USA
Posts: 1,408

awesomer - '04 Toyota prius
Thanks: 102
Thanked 252 Times in 204 Posts
I don't know at what point one controller makes sense though, maybe if you have a lead on 2 or 4 small motors that are just enough power for your needs (leads have to be the same length) and are on a tight budget. But if you have 4 regular motors, you are going to need so much battery that the extra power sections aren't gonna be noticed in the budget (and your controllers might need a controller, conceptually anyway, if you are trying to do stuff like traction control).

Quote:
Originally Posted by thingstodo View Post
.. They are measuring back-EMF from the motor and determining rotor position with some space vector math.
You have multiple rotor positions here (using current sensors), if you want FOC on multiple motors, you need multiple switches (IGBTs) and signals at a minimum so that the stator coils fire at just the right angle for each motor (though you still need some slip with FOC, I think it is mostly when changing speeds that it targets the highest torque vector). But a slip algorithm can also set slip for max torque, just not on the very first pulse.

Last edited by P-hack; 11-16-2014 at 01:01 PM..
  Reply With Quote