Go Back  

DIY Electric Car Forums > DIY EV Wiki > EV Information


Reply
 
Article Tools Display Modes
  #1  

Default AC Motor Selection

AC motor selection differs from DC Motor Selection because AC controllers may require a matching motor. In fact, most AC motors marketed for EVs come with a controller. These controllers often (but not always) include a built-in charger and DC-DC converter. Below is a list of AC motor and speed controller combinations.

Industrial VFDs (Variable Frequency Drives) usually have a smart "learning" feature to configure itself for a particular motor, and can therefore be used almost universally with 3 phase induction motors and in some case permanent magnet synchonous (BLDC) motors.

Some parameters may need to be entered such as:
Base voltage, base frequency, nameplate RPM, max speed, max current, magnetising current, number of poles, encoder pulses per rev, overload rating, and Star or Delta connection. This will allow the VFD to run in a very basic Volts/Hz mode, meaning it can control speed but not torque.

To run in a torque controlling mode, the VFD needs to "learn" (sometimes called "Auto tune") the motor characteristics. The VFD simply spins up the motor with no load on the shaft and generates an electrical model of the motor at various RPMs. Some VFD's can do these measurements on the fly as the motor is running, eliminating the need for Auto tuning. Sensorless vector mode uses Back EMF from the motor to measure motor speed, and control torque. Closed Loop Vector mode uses an Encoder to measure motor speed. The encoder has better accuracy, and enables finer control of speed and torque.


A VFD used in an EV must support vector control (torque control), and have access to the DC bus for connecting to the battery pack. Be aware that the VFD manufacturer may not warranty their product if used in an EV.

MotorControllerContinuous Power (hp/kW)Peak Power (hp/kW)Peak Torque (ft-lbs/N-m)Weight(lbs)/ Mass(Kg)Diameter (In/Cm)Length (Inc/Cm)Voltage Range (rms)Max rpmLink to Manufacturer or Retailer
AC Propulsion T-zeroT-zero?/?268/??/?110/5012in/305mm15in/381mm?/?13,000AC Propulsion
AC Propulsion AC-150AC 150?/?200/?165/225110/50240/45012,000AC Propulsion
Siemens 1PV5135-4WS28?90hp/67kW160hp/120kW317/430200/909.65in/245mm16.7in/425mm460V10,000Siemens
Solectria AC24DMOC44518.77/14@220V49.6hp/37kw57.66/78.1983.6/38.09.45/24.015.55/39.5?12,000Electroauto
Solectria AC55DMOC44546/?@220V63.0hp/47kw105/142234.35/?13.5/?16.4/??/?8,000Electroauto
ABB 3GAA 131 003-**EIndustrial VSD15hp/11kW50hp/37.5kW92/125115/5210.3in/260mm14.5in/367mm220V-690V6,000ABB
ABB 3GAA 131 315-**EIndustrial VSD15hp/11kW67hp/50kW122/165170/7710.3in/260mm18.5in/470mm220V-690V6,000ABB
ABB 3GAA 131 316-**EIndustrial VSD20hp/15kW80hp/60kW147/200178/8110.3in/260mm18.5in/470mm220V-690V6,000ABB
ABB 3GAA 131 317-**EIndustrial VSD25hp/18.5kW94hp/70kW203/275210/9510.3in/260mm18.5in/470mm220V-690V6,000ABB
ABB 3GAA 132 004-**EIndustrial VSD12.3hp/9.2kW34.5hp/26kW125/170130/5910.3in/260mm14.5in/367mm220V-690V4,500ABB
ABB 3GAA 132 315-**EIndustrial VSD15hp/11kW52hp/38.5kW192/260183/8310.3in/260mm18.5in/470mm220V-690V4,500ABB
ABB 3GAA 132 316-**EIndustrial VSD20hp/15kW80hp/60kW288/390203/9210.3in/260mm18.5in/470mm220V-690V4,500ABB
Notes For Reading Chart:
All voltages are given in RMS Voltage. If you wish to calculate the battery pack voltage necessary, simply multiply the desired or stated RMS value by 1.41 or sqrt(2).
Take the power figures as a guideline only. Most induction motors may be overpowered above their base speed by using a higher pack voltage, extending the constant torque region.
Remember, power (Watts) is the product of torque (Nm) multiplied by speed (rads/s or RPM/9.55). Power figures are stated for the motor's base speed, not the maximum speed.

Notes for Adding Motors:
If you are not comfortable in editing this wiki then post the information in the forums so they can be transferred to here.
These motors are ranked according to their power at their maximum voltage. Statistics would vary using smaller voltages.
I have sourced the information for the Siemens AC induction motor from
http://www.metricmind.com/audi/main.htm
For imperial and metric conversions just google a converter.
Hope you find this useful

External Resources:
Elithion's Motor Driver selection DC, Sepex, Brushless, Induction (July 2012)
Corbin Dunn's AC Motor Selection (April/May 2010)
Cameron Motor Works AC Drive Selection (August 2004)


Created by xrotaryguy, 08-02-2008 at 01:16 AM
Last edited by Elithion, 07-04-2012 at 01:01 PM
23 Comments , 49412 Views
  #2  
Old 08-02-2008, 08:52 AM
etischer etischer is offline
Senior Member
 
Join Date: Jun 2008
Location: San Francisco bay area
Posts: 989
etischer will become famous soon enough
Default Re: AC Motor Selection

The requirement to match a motor to a controller is a sales gimmick.

There are plenty of VFD's that can learn the properties of a motor allowing you to hook up any AC motor to that VFD. Manufacturers of controllers want to sell you a motor and drive combo. Instead of allowing the user to auto tune a motor, type in all the motor parameters and select proper feedback devices, they insist on you just selecting your motor from a list box.

Assuming the controller (VFD) is sized appropriately; allows the user to input motor data or auto tune the motor, and is populated with the correct feedback card (encoder, tachometer...), it should run an AC motor from any manufacturer.
Reply With Quote
  #3  
Old 08-04-2008, 08:51 PM
xrotaryguy's Avatar
xrotaryguy xrotaryguy is offline
Administrator
 
Join Date: Jul 2007
Location: Tempe AZ
Posts: 929
Blog Entries: 1
xrotaryguy will become famous soon enoughxrotaryguy will become famous soon enough
Send a message via AIM to xrotaryguy
Default Re: AC Motor Selection

I have seen a couple of chips that are actually designed to learn a motor curve. That's pretty impressive stuff. I guess I could have gone into more detail, but I didn't want to confuse the issue. Generally speaking, the AC motor controllers that most DIYers would be able to use come "pre-matched" so to speak. Most DIY EV builders lack the level technical knowledge required to install a non-EV VFD into an automobile let alone install a set of velocity sensing hall sensors and a reluctor and adapt it all to a random industrial AC motor.

Perhaps we could mention in this article that controllers do not necessarily need to be matched to the motor, but that most EV-specific AC controllers are part of a motor/controller combo to keep installation simple for the DIY EV converter.
__________________

Reply With Quote
  #4  
Old 09-15-2009, 07:20 AM
JRP3's Avatar
JRP3 JRP3 is offline
Senior Member
 
Join Date: Mar 2008
Location: Central New York
Posts: 7,813
JRP3 will become famous soon enoughJRP3 will become famous soon enough
Default Re: AC Motor Selection

Someone might want to add the MES and Brusa motors, or just put a link to the table here: http://www.metricmind.com/motor.htm
Also the lower power HPG motors should be mentioned: http://www.thunderstruck-ev.com/AC_d...erformance.htm
Reply With Quote
  #5  
Old 12-09-2009, 08:20 AM
JCR JCR is offline
Junior Member
 
Join Date: Nov 2009
Posts: 9
JCR is on a distinguished road
Default Re: AC Motor Selection

How can I determine Battey Pack voltage for a 15 KW AC motor. Is it as simple as what is stated ie such as 230/460 volts, etc. Can I get an inverter to take me from 96 VDC to 230 VAC and run the motor with decent performance?

Is it all in the windings of the AC motor? The HPGC AC-50 motors run on 96 volts so is it the design of the motor?

JCR
Reply With Quote
  #6  
Old 12-09-2009, 08:52 AM
major's Avatar
major major is offline
Senior Member
 
Join Date: Apr 2008
Location: Ohio, USA
Posts: 6,095
major has a spectacular aura aboutmajor has a spectacular aura about
Default Re: AC Motor Selection

Quote:
Originally Posted by JCR View Post
How can I determine Battey Pack voltage for a 15 KW AC motor.
Hi JCR,

Quote:
Is it as simple as what is stated ie such as 230/460 volts, etc.
Not quite. 230 would be the AC voltage for the 3 phase needed at the motor leads. The battery voltage needed to get 230 VAC when inverted would be about 320 VDC. IIRC, VDC = 1.4 times VAC, because you need the VDC to equal the peaks of the AC sine wave.

Quote:
Can I get an inverter to take me from 96 VDC to 230 VAC and run the motor with decent performance?
No. Unless you add a boost converter in front of the DC to AC inverter. And that is something you're unlikely to find.

Quote:
Is it all in the windings of the AC motor?
Pretty much so.

Quote:
The HPGC AC-50 motors run on 96 volts so is it the design of the motor?
Yeah, I guess they have them wound for that.

Regards,

major
Reply With Quote
  #7  
Old 12-09-2009, 12:00 PM
JRP3's Avatar
JRP3 JRP3 is offline
Senior Member
 
Join Date: Mar 2008
Location: Central New York
Posts: 7,813
JRP3 will become famous soon enoughJRP3 will become famous soon enough
Default Re: AC Motor Selection

The HPG motors can run higher than that, not sure how much higher in stock winding, but the Curtis controller they use cuts off at 130 volts.
Reply With Quote
  #8  
Old 12-09-2009, 09:40 PM
JCR JCR is offline
Junior Member
 
Join Date: Nov 2009
Posts: 9
JCR is on a distinguished road
Default Re: AC Motor Selection

Quote:
Originally Posted by JRP3 View Post
The HPG motors can run higher than that, not sure how much higher in stock winding, but the Curtis controller they use cuts off at 130 volts.
I see that with the HPGC AC50 motor running on 96 volts you run at 500 amps from out of the gate. Have you seen the motor curves .... I don't get the 500 amp straight line can someone help me out here?

JCR
Reply With Quote
  #9  
Old 12-10-2009, 06:57 AM
JRP3's Avatar
JRP3 JRP3 is offline
Senior Member
 
Join Date: Mar 2008
Location: Central New York
Posts: 7,813
JRP3 will become famous soon enoughJRP3 will become famous soon enough
Default Re: AC Motor Selection

Are you referring to this chart?
Reply With Quote
  #10  
Old 12-10-2009, 07:17 AM
major's Avatar
major major is offline
Senior Member
 
Join Date: Apr 2008
Location: Ohio, USA
Posts: 6,095
major has a spectacular aura aboutmajor has a spectacular aura about
Default Re: AC Motor Selection

Quote:
Originally Posted by JCR View Post
I don't get the 500 amp straight line can someone help me out here?
Hi JCR,

Thanks to JRP3 for posting the curve. It shows the maximum output for the motor and inverter. The "amp" trace is AC motor current. It is proportional to motor torque. So at low speeds, at maximum torque, current is about 550 Amps, AC. But at the low speeds, motor voltage is low. And as the RPM increase up thru 3000, the motor torque and current stay pretty constant. The motor voltage has been increasing as the RPM increase. At around 3000 RPM, the maximum available motor voltage is applied. Beyond 3000 RPM (base speed), the torque decreases as does the motor current because the motor voltage can no longer be proportionally increased.

Realize that this plot shows motor current and battery voltage. Battery current curve shape would resemble the shape of the Horsepower curve.

Hope that helps ya

major
Reply With Quote
Sponsored Links
Reply

Share or Bookmark this

Article Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

 

All times are GMT -6. The time now is 06:21 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2009 Green Web Publishing LLC
Ad Management by RedTyger