EVDrive and Some More Motor PrOn

Screen shot 2014-10-25 at 7.18.55 AM

Let’s start out by explaining that EV Drive EVDrive is not the same company as EV Drives, shall we?  I’m not too sure what EV Drives is all about, but they look like just a parts-seller, where EV Drive EVDrive is a much deeper parts + support + engineering and consulting company.  What marketing genius(es) are responsible for that little bit of confusion I don’t know, but someone needs to suck it up and change their name.  EV Drive EVDrive has, for a while now, been on my radar as a top-notch bunch of guys giving great support, but I can’t tell you the number of times I’ve looked for them and found EV Drives instead…  thinking they’d re-done their site, or worse, re-thought their company offering.

That bit of housekeeping out of the way, I’ve done a few posts on the Motenergy PMAC motor available from a few sources, and saw some comments on one by Steve at EV Drive EVDrive.  For my own reference, there was also a discussion on ElMoto about it which was (accidentally, I presume) deleted, and that’s here.  In those threads it was claimed that the EMS motor was an off-the-shelf product, and identical to the motor EV Drive EVDrive was offering as well.  The bottom line, as far as I’m able to find out, is that’s the case for all practical purposes.  There may be some cosmetic differences and maybe a temperature sensor or something, but it’s the same internals.

So what’s the deal on EV Drive EVDrive?  Well, where EMS offers the motor with only the Sevcon Size 4, the package offered by EV Drive EVDrive can be set up for the Sevcon Size 6, which is a good thing, at 600 some-odd amps.

Here are their specs:

  • Power: 21HP / 16kW cont., 47HP/35kW peak @ 5500 RPM
  • Torque:  27 ft-lbs cont., 66 ft-lbs. peak @ 132V
  • Torque constant of ~0.15 Nm per amp e.g. 300 amps/rotor or 45nm/33ft-lb peak for 120 secs –
  • Peak stall torque ~100nm
  • Design base speed at 120 VAC is 5700 rpm
  • System limits: (using Sevcon 150v peak Size 4) ~120 amps Continuous, ~300 amps for 60 secs. Peak, 360 amps for 10 secs Boost (size 6 Sevcon Size 6 also available – 120v peak ~550a/60secs 660a/10secs boost – 480amps AC 60 secs to motor, 660amps DC to controller)
  • AF single rotor – 8 magnets/rotor – ~92% efficient
  • 138v max/top-off batt pack ~132v nominal battery pack
  • Nominal/Maximum RPM:  ~5,500/6,500
  • Motor weight:  ~35lbs.
  • Motor gross dimensions: ~8.78in/223mm diameter,  ~6.6in/168mm body length
  • Axial Flux (AF) PMAC brushless motor with passive liquid-cooling for stators – 2 sets of in/out cooling ports on motor case plumbed in parallel with external fluid pump 15L/min minimum for higher cont. power output – 50/50 glycol/water – peak power is not improved vs. air-cooled version of this motor
  • This package comes with 3 hours of tech support included via SKYPE, or e-mail.

A couple of key points should be noted.

First, the Sevcon Size 6 is the controller that, when replacing the Size 4 on the Zero SR, made some huge improvements in the power and range from the bike with no other changes.

Second, the programming of the Sevcon is not an insignificant part of the motor/controller equation here.  Almost anybody, me included, can get the motor running.  Getting it running well?  That’s tougher.  Getting it running at it’s peak is, as a friend of mine says, “more art than science”, and depends on having the right software, a dyno, a test track and a whole lot of experience to know how to put all that together.  If you like hacking around, that’s one thing, but if you want to get the most out of it, this is a huge part of this system.

Third, the specs say this is a 38kW motor, but I’ve been told it can do over that – more in the neighborhood of 60kW, so do the math – you’re looking at 3.79 kw/kg, which ain’t bad for a proven motor with cooling, for a less than unobtainium price.  However, let’s not forget the difference between published specs and some guy saying something.  I know.  Ever the cynic.

They’re talking about a high-voltage package when they get the controller package dialed, running this motor at 150V.  They’re also talking about their own controller, which, reading between the lines will likely be a Reinhart spec’ed to their needs, but that’s just my butt talkin’.

EVD100-130-150-250-90-shaft-face-detailsOh.  Did you notice the bike in the splash page at the top?  Yeah, more on that in a few months.

One more thing – in my Quest for 100kW, I saw they have this Remy package: the “EVD100LV-Rcr-90p-344-360vdc matched motor & 100kW RMS Inverter/controller”, at a mere $16,000, but around 100lbs (for a 2.20 kw/kg score).

In this video you can meet the two main guys, Bob and Steve, and see this little bit of motor prOn in the flesh.  Aluminum.  Well, you get it.

Besides all that, some madman at EV Drive put four of them into this thing, and made it work.  Crazybus.



2 responses to “EVDrive and Some More Motor PrOn


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