Tuesday, May 13, 2014

One Soliton1 or 2 juniors?

"Hi Kerry,  I seem to remember you favoring the Soliton 1 controller because of the 1000A rating and the fact that you could use it to drive two motors. I thought that these motors can be run intermittently at >600A, to get to their peak ratings of 200 HP (or whatever they are). Would using a 1000A controller limit you to an intermittent rating of 500A per motor or do controllers have short-time ratings as well?
Do you see any disadvantage of buying a Soliton Jr (which I think is somewhere around 650A) and later upgrading to a second motor and Soliton Jr to double the power?"

Depends on a lot of things.  I am assuming you are keeping the transmission?  Do you plan on doing 2 motors or is that a slight chance?

The motor torque is proportional to the current.  So with 600 amps you make 60% of the torque as a 1000amp.  This torque will be constant from 0rpm up until the back EMF from the rotating motor becomes a limitation.  The warp 9 has a mechanical speed and voltage limitation that mean with a junior you will not go more then ~160 on a single motor.  This puts your peak power at input at 96kW (128hp).  Assuming ~85% eff that means 109hp at the "crank".  It's deceptive as it will feel like more power then a 109hp gas engine but it won't be a rocket ship.

If you go to dual motors then you can almost double the voltage and thus almost double the power to 200hp at the shaft.  But you need a battery pack with high voltage which is not necessarily a bad thing, just something to be aware of.

A single motor with the Soliton1 will let you do 1000amps at 160V giving you 187hp at the shaft and my experience is a good amount of power for spirited driving

Running 2 soliton jrs is possible but it will be a grand more expensive then one Soliton1 and more complex.  

Both the motors and the controllers have duty cycles but I really doubt that either of the evnetics controllers will be the limiting factor.