Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control - Page 94 - Fuel Economy, Hypermiling, EcoModding News and Forum

z_power · 08-20-2014, 11:28 AM

Suppose we change firmware in an AC controller and tie U, V, W outputs together. Doesn't it make a DC controller with synchronous rectification?

MPaulHolmes · 08-20-2014, 11:42 AM

heck yes it does!

MPaulHolmes · 08-21-2014, 12:15 PM

THANKS Z_POWER! EDIT: if anyone wants to buy this ac-31 Neighborhood Electric Vehicle MOTOR mislabeled as an ac-45 (there's no such thing as an AC-45 i guess) motor for their future AC Neighborhood Electric Vehicle conversion, and ship it to me for testing the AC controllers, I'll ship the motor to you (for free) after I get done with testing. It has the encoder, relatively low voltage (which I can easily replicate without going broke), and high phase currents. The high current will make the field oriented control easier to test, since I will have more resolution. I have a 1HP 230v 3 phase motor, which has like 0.33 amps per phase. haha. That would be about 1 tick of A/D resolution on the LEM current sensors I'm using. LOL.

It is only 32 HP, it is NOT 75HP!!!!!!!!! This would probably only be good for a smaller car that drives around the neighborhood at 25 or 30MPH.
Electric Vehicle EV Conversion AC 31 Motor w Adapter for VW 32HP | eBay

z_power · 08-21-2014, 12:36 PM

I have no personal experience but there's a few signals from other people involved: Buyer Beware: AC-45 and AC-46 Motors (my personal experience) - DIY Electric Car Forums and HPEVS statement: AC 31 on ebay

MPaulHolmes · 08-21-2014, 01:04 PM

I bet that's why the guy is selling it. He got it all ready to go in his car, and found out it is wimpier than advertised. I'm too darn trusting. But still, it would be perfect for testing. haha.

freebeard · 08-21-2014, 02:13 PM

Quote:

It is only 32 HP, it is NOT 75HP!!!!!!!!! This would probably only be good for a smaller car that drives around the neighborhood at 25 or 30MPH.

Is there a one-to-one correspondence of the electric motor's output vs the gas engine it replaces? Because the VW Beetle started at 25hp and it was designed for the Autobahn.

e*clipse hasn't been back since another thread on the 18th. Do you know anymore about the Highlander Hybrid M/G? Do you need one for testing?

MPaulHolmes · 08-21-2014, 02:30 PM

Well, this website said that there were people who did conversions that were freeway capable using the motor, but the cars tended to be on the lighter side:
"Some have had success with this set-up in light weight highway vehicles."
AC 31 on ebay

I was trying to lower expectations possibly more than necessary, so someone wouldn't be disapointed if they bought it.

Do I know about the highlander hybrid? I know nothing. haha

e*clipse · 08-21-2014, 04:46 PM

I've been around; just haven't said anything...

As far as I understand, you can get away with an electric motor rated at less power than the gas motor it's replacing. Generally, the electric motor's torque at startup is much better. I would make sure the torque specs are what you need (for the gearing you're using and the accelleration you want for the mass off vehicle you're using) AND that the motor can produce adequate power at the top speed you intend to drive it at. ( If you're using a fixed gearing system - like the Toyota MGR - then make sure it can produce enough power at top speed AT THE VOLTAGE you're using. One downside of BLDC motors (like the MGR) is that they are also generators. The voltage they generate at high speed apposes the voltage the controller is putting into the motor, reducing the power output. This is why field oriented control is important AND why high voltages are required on some motors. Advanced designs like the MGR are also partially reluctance motors, which helps reduce this effect with proper field oriented control.

I guess in reality there are quite a few variables involved... the quick answer is that a motor rated at 50kW (the MGR) will definitely be an adequate replacement for a gas motor rated at less than half it's power. A more real answer would require a lot more details.

I've done a silly amount of spreadsheets and other simulations to make sure I don't end up with a slug. These calculations include vehicle drag coefficient and frontal area, vehicle mass, tire diameter, battery pack voltage, etc, etc...

BTW, I found one for you on E*bay:
AWD Rear Carrier Differential Engine 2008 Lexus RX400 with 76 500 Miles | eBay

The Lexus RX400 is mechanically the same as the Highlander Hybrid. This one looks a little rough; like it's been on salty roads a lot. You probably could find one in better condition...

- E*clipse

Quote:

Originally Posted by freebeard

Is there a one-to-one correspondence of the electric motor's output vs the gas engine it replaces? Because the VW Beetle started at 25hp and it was designed for the Autobahn.

e*clipse hasn't been back since another thread on the 18th. Do you know anymore about the Highlander Hybrid M/G? Do you need one for testing?

MPaulHolmes · 08-21-2014, 04:57 PM

So, the motor is inside there??

e*clipse · 08-21-2014, 05:06 PM

Here's another one. It's in better shape, but has more miles on it. Also a bit more expensive.

Also notice, near the bottom of the listing, the compatible vehicles. That should help when looking for vehicles other than the LexusRX400.

http://www.ebay.com/itm/06-07-08-09-...4ee08d&vxp=mtr
- E*clipse