# AC motor controller, what spec would be nice?



## frodus (Apr 12, 2008)

> Pack DC voltage range?
> Motor AC voltage range?
> AC frequency?
> Current capacity?
> ...


Well, the biggest question is not really the inverter.... its finding motors. Most readily available motors are in the 120/208Y and 277/480Y flavors.... anything else and its going to be a purpose made motor.

So that being said:
pack voltage range: 250-350VDC

motor range: 208Y

frequency: 50/60hz motors are readily available, but if you could get a 400hz motor, you cut down on your weight and similar power..... i.e. aircraft motors. That'd change your voltage potentially, depending on those motor operating voltages.

Current capacity is misleading because its 3phase current.... so it may be better to operate in watts.... I'd say 50-100kw for most car conversions would be acceptable, with 100 and above being for higher end

throttle should be programmable between hall and pot

other circuits: contactor control, precharge control, several GPIO for driving gauges and dash lights and inputs from charger/etc for disable.

Construction: Modular is going to be hard, but its doable, but its doubtful that it can be offered as a modular "kit" for the average joe. Each setup should be fully tested, and if its too modular, it'd be impossible to test all configurations.


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## MJ Monterey (Aug 20, 2009)

Travis has a point. The controller specs need to reflect real world (available) motors.

Travis, do you think there is room for dramatic improvements on the controllers used with the AC55 motors?

Would a new controller benefit the AC50 from HPEV? http://hpevs.com/

The Siemens motors used by Ford are intriguing and lack a commercial controller. Would Siemens build more motors if they saw a new demand? Do they have other production motors that are viable for our use?


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## Woodsmith (Jun 5, 2008)

Thanks for the responses.
So I guess that it would make more sense to look at a specific motor, or motors, and produce a user friendly controller to work with it rather then an 'off the shelf controller to work with random average motors.

I take it that UK standard 440v 50hz 3ph motors wouldn't make a useful EV motor for various reasons.


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## Tesseract (Sep 27, 2008)

Woodsmith said:


> ... I take it that UK standard 440v 50hz 3ph motors wouldn't make a useful EV motor for various reasons.


Well, first off you would need an over 600V nominal DC bus, which limits your selection of fuses and switchgear quite a bit (to interrupt 600V _DC_ is hard). 

Next, if you follow the rule of thumb that says you can pull 4x the continuous power from an industrial motor for short, but useful, amounts of time, you'll probably want at least a 20hp motor at a minimum for an EV. Now take a look at how much the average 20hp industrial 3ph. AC induction motor weighs. Heavy little bastards, aren't they?


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## MJ Monterey (Aug 20, 2009)

Woodsmith said:


> I take it that UK standard 440v 50hz 3ph motors wouldn't make a useful EV motor for various reasons.


The words of an electrician friend float back to me.....

120 ac tingles
240 ac is painful
360 ac will knock you on your butt if not throw you against the opposite wall
anything more than that has a very high probability of death.........


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## yarross (Jan 7, 2009)

Woodsmith said:


> Pack DC voltage range?
> Motor AC voltage range?
> AC frequency?
> Current capacity?
> ...


The obvious way is to modularize control board and power stage, and use different power stages (MOSFETs or IGBTs with different amperages) with the same control board. Even driver boards can be the same for any power stage. Now you have the base to compose almost any suitable combination.



Woodsmith said:


> Do you think it would be worth doing?


Definitely YES.


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## ehustinx (Dec 23, 2009)

MJ Monterey said:


> Travis has a point. The controller specs need to reflect real world (available) motors.
> 
> Travis, do you think there is room for dramatic improvements on the controllers used with the AC55 motors?
> 
> ...


Hi,

The Siemens motors/generators of the series 1PV5/1FV5 are in production. 
They are available through HEC (www.hec-drives.com). Please contact HEC for technical details and pricing.

Best regards,

Eddy Hustinx
HEC


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## Salty9 (Jul 13, 2009)

> I had a thought this week, now I am back at work and college is all in one building I can go up stairs and see the engineering department, so I did.
> 
> I thought that they may be able to include an EV related project to throw at the students so I thought I would throw it at them and see what they threw back.


Woodsmith,

Has there been any further movement on the proposal to your engineering dept? If not, is there enough interest here to try an open source bldc controller project here?

Chuck


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## samborambo (Aug 27, 2008)

Getting a motor custom wound to keep the pack voltage down isn't that daunting or expensive. When buying a new motor, it's not much more than the off-the-shelf cost to have a custom wound option.

As it happens, this is what CMG motors is doing for me. I'm placing my order this week as soon as I get this f***ing halfshaft back into the gearbox and confirm the motor flange size will fit.

For a pack voltage of 320VDC, use a 4-pole 50Hz 1450RPM 230VAC 11kW motor with a short term overload rating of 3x. Custom wind option for the motor at 1/3 voltage @ 50Hz comes to 77VAC. At 150Hz 4350RPM the voltage is 230VAC at the same current/torque as the base speed. Theoretical peak power is 99kW but I'm derating slightly due to the increase iron losses. I expect 2.5x or 82kW. I haven't queried CMG whether thinner laminations in the stator core are an option. This would help maintain full power at higher frequency.

CMG can also option flying leads instead of a terminal box, seperate cooling instead of shaft mounted centrifugal fan, etc. The model series is SLA Aluminium frame.

Delivered for under NZ$1000 (US$740).

Sam.


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## Bowser330 (Jun 15, 2008)

samborambo said:


> Getting a motor custom wound to keep the pack voltage down isn't that daunting or expensive. When buying a new motor, it's not much more than the off-the-shelf cost to have a custom wound option.
> 
> As it happens, this is what CMG motors is doing for me. I'm placing my order this week as soon as I get this f***ing halfshaft back into the gearbox and confirm the motor flange size will fit.
> 
> ...


please keep us updated on this...740$ USD for a 110hp (82kw) motor! NICE!


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