# AC vs DC systems



## jeremyjs (Sep 22, 2010)

The biggest problem with AC is the cost. It looks like the AC system is usually 2-3x the cost of an equivalently powerful DC system. Sure you get regen and a slight efficiency boost, but you'll get much more range/power by just spending the difference in price on more/bigger batteries. 

When you start talking about big power in both motor and controller there isn't even any competition readily available that could compete with the DC systems that are readily available.


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## ElectriCar (Jun 15, 2008)

DC is cheap compared to AC and is less energy efficient. DC motors are subject to arcing and total destruction if you push them much or they have a brush failure. DC motors in EV's have regen issues. It's not hard for industrial controllers but I guess EV controller builders just aren't so smart or it's too expensive to do properly and safely, I don't know why but that's the way it is.

AC systems require a first born or equivalent if you want a bolt on EV drive. They do however easily do regen thus save on your brakes, recharge your batteries a bit thus extending your range (very good for hilly areas and city traffic) and have no arcing issues so less likely to self destruct. 

AC motors are also easily reversible and some are very high RPM capable thus eliminating weight and the need for a transmission. Much higher voltage capability versus DC and thus smaller wire thus more weight savings and less stress on your batteries thus extending the life of your $12000 lithium pack.

If you're electronically very saavy and have some help, you can convert an industrial inverter for EV use pretty economically. I would try it but don't want the challenge nor do I want to put in the time.


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## jimy_f_84 (Jun 3, 2011)

Thanks guys for the info, keep it coming.

So far the difference i can find: 

AC is regen capable
AC is more effecient
AC is more expensive
AC has better range/performance


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## Duncan (Dec 8, 2008)

_AC is regen capable_
_AC is more effecient_ -the motor is more efficient - the controller less - its a wash
_AC is more expensive_ - in spades!
_AC has better range/performance_ - for the same money DC has better range/performance


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> ...It's not hard for industrial controllers but *I guess EV controller builders just aren't so smart* or it's too expensive to do properly and safely, I don't know why but that's the way it is.


Yeah, we're a real dim bunch... I know I must be, anyway, because my peers in power electronics design make 2.5x more per year than I do (and they get benefits like health insurance, paid vacation, etc...). 

I'm not really sure what your statement that "it's not hard for industrial controllers" is supposed to mean, but I assume you are trying to claim that industrial controllers aren't that expensive or are otherwise eminently reasonable choices to modify for EV use since you make the latter claim later on in the post.

So, let's take a stroll through teh internetz and see what AC drives cost. I'll use Baldor as a representative example as it's not the cheapest nor the most expensive brand:

Baldor VS1GV Vector Drive

Just for reference, the Soliton1 is a 300kW (400hp) DC drive with a retail price of $3000. An AC drive of comparable amount of power from Baldor will set you back a cool $45k while spending the same amount of money as what a Soliton1 costs will get you a (bicycle) tire blistering 10hp. 

Of course you can find AC drives for less - particularly if you buy a used one off of ebay - but that's a high-risk proposition (does it *really* work?) and you'll still need to modify it for under-hood use in a road-going vehicle (ie - ensure it can run on straight DC, harden it against vibration, dust and incidental water splash, etc.). Oh, and prepare for needing a 680V battery pack, because the hp rating of 240VAC drives rarely exceeds 60hp.


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## cruisin (Jun 3, 2009)

Tesseract said:


> Yeah, we're a real dim bunch... I know I must be, anyway, because my peers in power electronics design make 2.5x more per year than I do (and they get benefits like health insurance, paid vacation, etc...).
> 
> I'm not really sure what your statement that "it's not hard for industrial controllers" is supposed to mean, but I assume you are trying to claim that industrial controllers aren't that expensive or are otherwise eminently reasonable choices to modify for EV use since you make the latter claim later on in the post.
> 
> ...


Another advantage of the AC-50 is that you dont need as much battery since 35 cells will do the job. The AC is much more programmable and very smooth in its operation. email me at [email protected] and I will help you save a bunch $$$.


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## Yabert (Feb 7, 2010)

cruisin said:


> Another advantage of the AC-50 is that you dont need as much battery since 35 cells will do the job.


It's only true for low power AC system.



> The AC is much more programmable and very smooth in its operation


No really!


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## cruisin (Jun 3, 2009)

Yabert said:


> It's only true for low power AC system.
> 
> 
> No really!


Yes really, the programmability of the 1238 is unlike any DC on the market. I have done them all and installed them all. In my classes as a instructor I let the students comapare and AC wins hands down. Name one production EV or hybrid car that is available with a DC motor and controller. I wander why?


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## Qer (May 7, 2008)

I see crusin is trying to cram a deal again, although I almost managed a C|N>K seeing him trying to sell one to Tesseract.


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## Qer (May 7, 2008)

cruisin said:


> Yes really, the programmability of the 1238 is unlike any DC on the market. I have done them all and installed them all.


Since I've put a lot of effort in trying to make the Soliton handle changes in throttle very smooth and haven't heard anyone else complained that it'd be rough or jerky in it's behaviour I would like to know more about your experience with the Soliton.

In what situations does it misbehave? Have you set A/s to extremely high and that could be the cause? Any chances you could provide me with logs from your setup so I could try to improve the behaviour?


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## EVfun (Mar 14, 2010)

cruisin said:


> Another advantage of the AC-50 is that you dont need as much battery since 35 cells will do the job. The AC is much more programmable and very smooth in its operation. email me at [email protected] and I will help you save a bunch $$$.


You sound like a used car salesman.


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## Tesseract (Sep 27, 2008)

cruisin said:


> Another advantage of the AC-50 is that you dont need as much battery since 35 cells will do the job. The AC is much more programmable and very smooth in its operation. email me at [email protected] and I will help you save a bunch $$$.


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## cruisin (Jun 3, 2009)

Qer said:


> I see crusin is trying to cram a deal again, although I almost managed a C|N>K seeing him trying to sell one to Tesseract.


Thats interesting, I dont see you helping anybody, just critisizing.


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## Yabert (Feb 7, 2010)

Cruisin please stop saying to everyone that a DC system is not smooth in its operation......

You maybe have had a problem with your DC controller Kelly, but that's no reason to give false information to everyone.
Watch the smoothness of operation from 1:03 to 1:35: http://www.youtube.com/watch?v=La7nST0w38M


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## cruisin (Jun 3, 2009)

Yabert said:


> Cruisin please stop saying to everyone that a DC system is not smooth in its operation......
> 
> You maybe have had a problem with your DC controller Kelly, but that's no reason to give false information to everyone.
> Watch the smoothness of operation from 1:03 to 1:35: http://www.youtube.com/watch?v=La7nST0w38M


With 40 years experience in the business and on the Tesla team in 2009, I would think I would be able to express my opinion backed up with a whole lot more experience than you ever dreamed of. I do provide false information like you do.
I looked at your youtube, what a freaken joke.


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## Sunking (Aug 10, 2009)

jimy_f_84 said:


> Planning my conversion to stop using gas and supporting the oil companies.


Huh? Where do you think electricity comes from?


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## Qer (May 7, 2008)

Sunking said:


> Huh? Where do you think electricity comes from?


In US:

44.9% Coal
23.4% Natural gas
20.3% Nuclear
6.9% Hydroelectric
3.6% Other renewable

aaaaand oil comes in at mere 1%.

You guys could learn from France (must be the only thing that country got right, except for food): 78.1% nuclear, less than 10% of the electricity comes from fossil fuel...


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## Tesseract (Sep 27, 2008)

cruisin said:


> With 40 years experience in the business and on the Tesla team in 2009, I would think I would be able to express my opinion backed up with a whole lot more experience than you ever dreamed of. I do provide false information like you do.
> I looked at your youtube, what a freaken joke.


You have a really peculiar approach to sales, cruisin, but who am I to criticize? Indeed, I encourage you to keep on keepin' on! 

In the meantime, how about this YouTube video? Not cruisin; Smokin!


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## ElectriCar (Jun 15, 2008)

Tesseract said:


> Yeah, we're a real dim bunch... I know I must be, anyway, because my peers in power electronics design make 2.5x more per year than I do (and they get benefits like health insurance, paid vacation, etc...).
> 
> I'm not really sure what your statement that "it's not hard for industrial controllers" is supposed to mean, but I assume you are trying to claim that industrial controllers aren't that expensive or are otherwise eminently reasonable choices to modify for EV use since you make the latter claim later on in the post.
> 
> ...


deleted...


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## jimy_f_84 (Jun 3, 2011)

Ok,

This is going out of hand, this is one thing i do not like about forums, the threads in my opinion are not meant for arguements about opinions, there is a saying that says an opinion is like an A** hole everybody has got one, so alot of us has different opinions, take them read them and learn from them, compare for your self and leave it alone.

The use of fossil fuels for electricity is near nothing compared to the use of gasoline to run vehicles, i run on solar and wind here, do not use the grid, but i am doing my part SUNKING, so i think anything helps.

Anyway, thanks Crusin for the info, your doing what you think is good in your opinion and that helps, thanks for all your input guys, keep them coming.


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## ElectriCar (Jun 15, 2008)

My bad Tes. I totally misread your reply. My apologies dude, seriously.


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## jimy_f_84 (Jun 3, 2011)

Tesseract said:


> Yeah, we're a real dim bunch... I know I must be, anyway, because my peers in power electronics design make 2.5x more per year than I do (and they get benefits like health insurance, paid vacation, etc...).
> 
> I'm not really sure what your statement that "it's not hard for industrial controllers" is supposed to mean, but I assume you are trying to claim that industrial controllers aren't that expensive or are otherwise eminently reasonable choices to modify for EV use since you make the latter claim later on in the post.
> 
> ...


Tess, i reread your post and yes you are right, the AC drives are mostly 2-3 times as expensive as DC, as far as i see around the internet.

You make a good point
Thanks alot.


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## Tatsushige (Mar 24, 2011)

Sorry Off Topic 

Tesseract just had a look see at your site, do you have any more photos of the Orange Mucielago Replica by Ecos Motors Harbinger??

I like it .. looks good


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## jimy_f_84 (Jun 3, 2011)

So found AC 50 motor + Curtis 1238-8501 controler with some stuff for $4600 at a local place in WA, looking at the info on motor and controller they compare close to the Warp9 but with higher voltage.

Any thoughts?


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## jimy_f_84 (Jun 3, 2011)

I do not really care for Regen, as its alot of work and cost for not much results, i would rather use that cash and buy a solar panel and system to leave at work and let it charge my car while i spend my 10 hours there.

Right?


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## cruisin (Jun 3, 2009)

jimy_f_84 said:


> So found AC 50 motor + Curtis 1238-8501 controler with some stuff for $4600 at a local place in WA, looking at the info on motor and controller they compare close to the Warp9 but with higher voltage.
> 
> Any thoughts?


That system should not cost more than $4400 to members. Make sure the programming of the 1238 is per your specs or else you will get what you may not like. No more concern about arcing like a DC, no more concern about brushes like a DC, no more concern about over heating internally like a DC, and no more groaning coming from the controller like the DC. If you need more info I am here to help unlike some of the others. Thats why I teach EV conversion and have been for more years than I can remember.


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## cruisin (Jun 3, 2009)

jimy_f_84 said:


> I do not really care for Regen, as its alot of work and cost for not much results, i would rather use that cash and buy a solar panel and system to leave at work and let it charge my car while i spend my 10 hours there.
> 
> Right?


Regen is a lot of work? Where did you come up with that? Tell us what you are talking about so that we can understand. Details please.


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## ElectriCar (Jun 15, 2008)

If you live in a flat area and drive mostly interstate, regen may not be worth it. In my area I encounter hills and traffic signs & lights all the time. In my case I think it would be worth it. During decelleration I could be converting inertia into electrons instead of heating brake rotors.


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## jimy_f_84 (Jun 3, 2011)

cruisin said:


> Regen is a lot of work? Where did you come up with that? Tell us what you are talking about so that we can understand. Details please.


Let me correct my self, as for a DC system i mean Regen is too much work for the result, as for AC its not, sorry.


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## jimy_f_84 (Jun 3, 2011)

cruisin said:


> That system should not cost more than $4400 to members. Make sure the programming of the 1238 is per your specs or else you will get what you may not like. No more concern about arcing like a DC, no more concern about brushes like a DC, no more concern about over heating internally like a DC, and no more groaning coming from the controller like the DC. If you need more info I am here to help unlike some of the others. Thats why I teach EV conversion and have been for more years than I can remember.


Cruisin, thank you for all the info.


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## Yabert (Feb 7, 2010)

jimy_f_84 said:


> So found AC 50 motor + Curtis 1238-8501 controler with some stuff for $4600 at a local place in WA, looking at the info on motor and controller they compare close to the Warp9 but with higher voltage.


No direct comparison can be made because for the same 4600$ you can buy a Warp9 and a Soliton 1.

AC 50 can give: 50-60 hp peak
Warp9 / soliton1: 150-200 hp peak

The best deal for your buck is to rebuild an old forklift dc motor (100-400$) and buy an controller for your power requirement. If you don't need high power, they have few good DC controller for 300-600$(- 30 Hp). High power controller can cost 800-2900$.


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## major (Apr 4, 2008)

jimy_f_84 said:


> I do not really care for Regen, as its alot of work and cost for not much results, i would rather use that cash and buy a solar panel and system to leave at work and let it charge my car while i spend my 10 hours there.
> 
> Right?


Wrong. Everytime I've used regen it has been free. That is, it is an automatically included feature of the motor controller package. O.K. Maybe 50 to 70 bucks more if you want the control on the brake pedal. And I guess it does take a few minutes to set the brake parameters to suit your fancy.

Figure that against your return on investment buying and installing your solar panel  Not that there is anything wrong with that. I like solar PV. 

Just do an EV system (and/or PV) which you want to do and fits your lifestyle and budget. Have fun with it. 

major


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## GizmoEV (Nov 28, 2009)

Qer said:


> In US:
> 
> 44.9% Coal
> 23.4% Natural gas
> ...


Depends. Here is the fuel mix for my area:

Coal 6.3%
Hydroelectric (Water) 82.9%
Natural Gas 2.5%
Nuclear 7.8%
Other* 0.5% _*Includes the following fuel types - biomass, landfill gas, petroleum and waste incineration._


So less than 3% petroleum based and less than 9.3% petroleum based.


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## jeremyjs (Sep 22, 2010)

Yabert said:


> No direct comparison can be made because for the same 4600$ you can buy a Warp9 and a Soliton 1.
> 
> AC 50 can give: 50-60 hp peak
> Warp9 / soliton1: 150-200 hp peak
> ...



Exactly. An AC system is simply more expensive for a given amount of power. I don't see anyone saying AC systems are bad. I personally believe they're better than DC. I just don't see the benefits of them outweighing the significant cost difference for a comparably powerful system.

If you were doing an all out, cost is no object, type of project. A high end AC system would probably be worth it.


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## Qer (May 7, 2008)

jeremyjs said:


> I don't see anyone saying AC systems are bad. I personally believe they're better than DC. I just don't see the benefits of them outweighing the significant cost difference for a comparably powerful system.


I think it depends on the situation so I don't think you can say that an AC system automatically is better (even if the cost is ignored). One thing you have to remember is that DC-systems are easier to compare since most motors are very similar in the way they're constructed and the controllers are just a buck-converter. Sure, the controllers can have different features and stuff, but the most basic function is just a buck-converter so they work pretty much the same (although some don't do it for very long before the magic smoke escapes  ).

AC-inverters are a lot more complicated and there's at least three (probably more) different algorithms for how to control the motor (and all aren't suitable for running an EV). That means that even when you compare AC-inverters it's a bit of an "apples versus oranges"-thing going on unless you know that the two inverters for example use the same algorithm (which will, for example, affect zero RPM torque etc). Then, of course, there's the difference in calculating all the parameters on the fly (the best but very CPU intense) or using pre-calculated look-up tables. Etc, etc, etc. And etc.

Then there's the matching aspect. For series wound DC-motors there's no such thing as a matching to be done, for SepEx you have to make sure the field mapping is correct and for AC there's almost an 1:1 correlation between motor and controller, which of course complicates things even more.

So AC or DC? I think most people here makes this a lot more complicated than it really is. If you think you really benefit from regen, go AC. If not, well, it's your money but I'd dare to say that most people would never notice the difference in their daily commuting and spending twice the money (or more) to just get rid of the brushes doesn't make sense.

There's a few Renault Clios here in Sweden that's more than 15 years old and keeps going strong. The owners has formed a community where they help eachother to find replacement batteries, short out dead cells, convert to Lithium, replace faulty electronics, rebuilding and improving the cars in general and so on. There's of course regularly problems with the cars since they're really old and especially the batteries are a constant source of problems but I've never heard anything about there being problems with the SepEx-motors. Brushes wear down, sure, but unless you're overloading the motor it's a very minor problem.

So which one's best? An AC system has it's pros for me, but that's not because of performance (anything that gives me decent commuting performance is ok) or regen (where I live it's flatter than flat, won't get a bit from regen), it's because I live at a gravel road. I like the idea of a sealed motor since some seasons the road is anything but electricity friendly. Like right now, when parts of the road could be used for mud wrestling. There's good reasons for why we bought a Jeep... 

Of course, I could use DC too, I'd just have to add a blower with an air filter and make sure the motor's decently sealed for mud splashes. More work, but quite possible, a lot cheaper and, of course, I could use a Soliton. 

So which is best? I'd say either. Every time someone converts a gasser to an EV it's a gain. AC or DC? Personally I'd rather consider stuff that matters, like fabric or leather seats. I'll notice THAT difference a lot more in my daily life...


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## Tesseract (Sep 27, 2008)

ElectriCar said:


> My bad Tes. I totally misread your reply. My apologies dude, seriously.


S'awright. Apology accepted. Seems you weren't the only one to misread my reply...



jimy_f_84 said:


> Tess, i reread your post and yes you are right, the AC drives are mostly 2-3 times as expensive as DC, as far as i see around the internet.


Hmm... I'll admit my writing style can be a bit squirrelly at times, but what part did you find confusing? I'll go edit it if I can figure out a way to make it clearer.



Tatsushige said:


> Tesseract just had a look see at your site, do you have any more photos of the Orange Mucielago Replica by Ecos Motors Harbinger??


As a matter of fact... Someone posted a photo album of the Harbinger at SEMA:

ECOS Motors - Harbinger



jimy_f_84 said:


> So found AC 50 motor + Curtis 1238-8501 controler with some stuff for $4600 at a local place in WA, looking at the info on motor and controller they compare close to the Warp9 but with higher voltage.
> 
> Any thoughts?


From what I've heard and read the AC-50 is a great little combo, but with the same peak power as the 1.0L Geo Metro engine it's woefully underpowered for most road-going conversions. Programming all of the parameters is a bit cumbersome (to be fair, that's a common trait of AC inverters) and requires a special programming "pendant" (which, IIRC, costs $500) or you have to yank the controller out of the vehicle and send it back to the company you bought it from to make any changes for you. That is so cumbersome it, to me, renders the AC-50 a non-starter unless you are willing to buy the programmer.

Just my $0.02 and not even remotely unbiased, so take with the proverbial grain o' salt, etc...


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## ElectriCar (Jun 15, 2008)

major said:


> Wrong. Everytime I've used regen it has been free. That is, it is an automatically included feature of the motor controller package. O.K. Maybe 50 to 70 bucks more if you want the control on the brake pedal. And I guess it does take a few minutes to set the brake parameters to suit your fancy.
> 
> Figure that against your return on investment buying and installing your solar panel  Not that there is anything wrong with that. I like solar PV.
> 
> ...


I like that brake pedal feature! If you don't install it then you only get partial benefit and either don't have enough regen or too much causing you to waste power.


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## ElectriCar (Jun 15, 2008)

Tesseract said:


> Just for reference, the Soliton1 is a 300kW (400hp) DC drive with a retail price of $3000...


See, that's why we want you guys to develop an AC system!


Tesseract said:


> Of course you can find AC drives for less - particularly if you buy a used one off of ebay - but that's a high-risk proposition (does it *really* work?) and you'll still need to modify it for under-hood use in a road-going vehicle (ie - ensure it can run on straight DC, harden it against vibration, dust and incidental water splash, etc.). Oh, and prepare for needing a 680V battery pack, because the hp rating of 240VAC drives rarely exceeds 60hp.


I have a vendor who deals in industrial reselling, buying entire plant equipment in distress sales! I can get drives really cheap as they throw them away at times! I just have no real desire to give up a boat load of time to figure out ONE drive with no guarantee of success. I've found Baldor doesn't have any desire to help in the endeavor either as I've already tried once when I was considering a drive hack.


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## pedm (May 2, 2011)

ElectriCar said:


> DC motors are subject to arcing and total destruction


Hi!

I have choose a DC system SepEX (Kostov9'' and Kelly HSE14801). It seams more simple for beginners. And I leave in a hilly area, so I'm going to use the regen for a long period. 

I am afraid of this arcing effect.


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## jddcircuit (Mar 18, 2010)

I like reading about the pros and cons between AC and DC and then adding in the cost$ factor.

Speaking of AC control, does anyone know or have an idea why I can't buy an off the shelf control solution that interfaces with a junk yard Prius inverter and electric transaxle combination. The motor inverter combo is already designed for harsh road and weather conditions that were mentioned earlier. The motor/gearbox and inverter are liquid cooled and splash proof and are relatively inexpensive. I am also willing to bet that this motor could be pushed to higher peak power ratings with controlled risk like we do with other motors. Even if you did burn up the stator winding or demagnitize the rotor it is still relatively inexpensive and easy to replace these pieces. Even dual setups for both front and rear drive is not hard to imagine for larger vehicles.

I am interested why the DIY community and suppliers is not aligning itself this way.

Is it because the control algorithm is too complex?
Is it because of liability or infringement issues?
Is it because this motor/inverter combo is inadequate?
Is it because there is less way to make money on it?

I am working on trying to build my own control circuit and control algorithm but I am sure someone with more experience like those on this forum would be more likely to succeed. I am not recommending it as a solution for today since the control board doesn't exist but going forward it seems like it has potential to be a low cost alternative very soon.

Regards
JDD


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## JRP3 (Mar 7, 2008)

Don't they run at over 600V? Kind of a pain to deal with if so.


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## JRP3 (Mar 7, 2008)

Tesseract said:


> From what I've heard and read the AC-50 is a great little combo, but with the same peak power as the 1.0L Geo Metro engine it's woefully underpowered for most road-going conversions.


I admit it's probably not neck breaking acceleration but I can't imagine calling it woefully underpowered. My AC 31 can start out in second gear even on hills and go all the way to 65 without shifting, I've easily hit 75mph and have no idea what top speed is.


> Programming all of the parameters is a bit cumbersome (to be fair, that's a common trait of AC inverters) and requires a special programming "pendant" (which, IIRC, costs $500) or you have to yank the controller out of the vehicle and send it back to the company you bought it from to make any changes for you. That is so cumbersome it, to me, renders the AC-50 a non-starter unless you are willing to buy the programmer.


Of course there is another way


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## Tesseract (Sep 27, 2008)

JRP3 said:


> I admit it's probably not neck breaking acceleration but I can't imagine calling it woefully underpowered.


Well I can easily imagine it... After all, I can turn a Soliton1 down to imitate an AC-50 (or -31 or whatever) but you can't turn an AC-50 up to imitate a Soliton1... 



JRP3 said:


> Of course there is another way [to program the AC-50]


I stand corrected. Now all you need to do is find a USB to Serial dongle that works with the Curtis *and* your computer. What Could Possibly Go Wrong?©


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## JRoque (Mar 9, 2010)

Hello all. I keep getting my math wrong on this AC vs DC comparison. When I look at the AC50 package, I can't make the numbers work to have it be 3 times more expensive than comparable DC solutions.

Comparing at a pack voltage of 120V, the AC-50 provides the motor, controller, all cables, display and shaft speed sensor. I believe it only needs an external contactor to be a complete system. It can do 650A @ 120V = 70kW or 104HP peak. Yes, with some DC systems of similar cost you can increase power with a larger pack but that increases the overall cost and weight. Still, the DC system will edge up the AC-50 by a bit but certainly not 2 or 3 times as much.

I'm not sure I'd consider regen as a serious criteria when comparing with a DC system. I think of of regen as a 'free' bonus that happens to come with AC systems. As mentioned above, regen does not put significant amounts of power back in the batteries and then only at limited opportunities during normal driving. While it does save brake pad wear, it transfers some of the wear to the clutch and transmission components. Regen only cannot be safely used to stop a car because it only effects two of the wheels.

JR


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## JRP3 (Mar 7, 2008)

Tesseract said:


> Well I can easily imagine it... After all, I can turn a Soliton1 down to imitate an AC-50 (or -31 or whatever) ....


Really, you can make a Soliton1 do regen, and reverse electronically without contactors? 



> I stand corrected. Now all you need to do is find a USB to Serial dongle that works with the Curtis *and* your computer. What Could Possibly Go Wrong?©


I'll let you know 
http://www.amazon.com/IOGEAR-Serial-Converter-Cable-GUC232A/dp/B000067VB7


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## JRP3 (Mar 7, 2008)

JRoque said:


> Regen only cannot be safely used to stop a car because it only effects two of the wheels.
> 
> JR


It can probably stop a car quite safely about 99% of the time as Tesla and MiniE drivers will tell you.


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## JRoque (Mar 9, 2010)

Hi.



JRP3 said:


> It can probably stop a car quite safely about 99% of the time as Tesla and MiniE drivers will tell you.


Hmm, didn't know that. I can't see how they can pass a safety standard test with 2 wheel brakes. I suppose you can use ABS to engage the other two mechanically if the electric stop (ie: regen) start locking up. A rear drive car that just uses those two back tires to stop won't be very effective at it. You probably remember as a youngster (err... younger than the young you are now ) how much fun it was to be driving at 55 MPH next to someone and pull the handbrake to make noise and smoke. Didn't really stop the car much.

JR


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## JRP3 (Mar 7, 2008)

The cars do have conventional brakes of course, so safety tests are not an issue. I believe they've programmed regen to disengage when the ABS activates, though of course as soon as the wheels stop turning the regen would also stop, but it may be too complicated to integrate that with the ABS.


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## ElectriCar (Jun 15, 2008)

The purpose of regen is not to stop a vehicle. It is to capture inertia and convert it back to electricity instead of braking and wasting that inertia on heat. Industrial machinery uses it to slow machines when it's told to stop under normal conditions. An emergency machine stop or braking however requires more than regen. 

Regen can be controlled by an interface with your brake pedal which will apply regen in some proportion to pedal travel. A slight touch will apply slight regen while heavy braking will apply more regen.


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## JRP3 (Mar 7, 2008)

It's also easily variable with the accelerator pedal.


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## Tesseract (Sep 27, 2008)

JRP3 said:


> Really, you can make a Soliton1 do regen, and reverse electronically without contactors?


The regen part, yes. At least the hardware is there to flip the controller operation from buck mode to boost mode. Too bad we have yet to figure out a way to not blow up advanced timing motors, however...

The electronic reverse... well, you got me there.


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## drgrieve (Apr 14, 2011)

Didn't know that the soliton could regen?!? Would this be possible on the warp 11HV? [This has neutral brushes for those that don't know.]

I live in a hilly area with lots of stop and go so naturally this tweaks my interest! I try to coast a lot in my ICE, but where I live they have a habit of putting a speed camera in the valley of two hills. Evil is what that is.


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## Tesseract (Sep 27, 2008)

drgrieve said:


> Didn't know that the soliton could regen?!?


It can't. Re-read what JRP3 wrote and I responded.


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## tomofreno (Mar 3, 2009)

> Comparing at a pack voltage of 120V, the AC-50 provides the motor, controller, all cables, display and shaft speed sensor. I believe it only needs an external contactor to be a complete system. It can do 650A @ 120V = 70kW or 104HP peak. Yes, with some DC systems of similar cost you can increase power with a larger pack but that increases the overall cost and weight. Still, the DC system will edge up the AC-50 by a bit but certainly not 2 or 3 times as much.


 It seems to compare favorably with a 500A controller and 9" series DC motor like many past conversions have used. The ADC FB1 4001 has about 110 ft-lb torque at 500A, and about 70 H.P shaft power. The AC50 with the 650A controller would have about the same max torque as the 4001 out to about 4000 rpm at 120V, so about 62kW, 83 H.P. peak shaft power. The AC31 has higher max torque, around 130 ft-lb with the 650A controller I think, but only out to about 2600 rpm at 120V, so about 48kW, 64 H.P. peak shaft power.

As far as stopping with regen, I've had no problem including driving on snow the last two winters. Of course I don't try any sudden changes in momentum and leave plenty clearance from the car in front of me when driving on snow, but I've always driven that way. And yes, you get everything but the contactor with the kit including a Curtis gauge that reads out battery V, I, rpm, motor temp, and controller temp. I think the AC50/650A controller would work well for a Honda Civic or similar for every day driving including highway, but more power would be required to do 0 to 60 in say less than 12 seconds.


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## coulombKid (Jan 10, 2009)

drgrieve said:


> Didn't know that the soliton could regen?!? Would this be possible on the warp 11HV? [This has neutral brushes for those that don't know.]
> 
> I live in a hilly area with lots of stop and go so naturally this tweaks my interest! I try to coast a lot in my ICE, but where I live they have a habit of putting a speed camera in the valley of two hills. Evil is what that is.


 So is that bicycle rack over my plate and that berka over my face! ; )


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## GerhardRP (Nov 17, 2009)

Tesseract said:


> The regen part, yes. At least the hardware is there to flip the controller operation from buck mode to boost mode. Too bad we have yet to figure out a way to not blow up advanced timing motors, however...


All of the Kostov motors have interpoles and are neutrally timed. Have you tested regen on one of them?
Gerhard


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## JRoque (Mar 9, 2010)

Hi. If I'm not mistaking, you need a Sepex or PM motor to get regen out a DC machine so it's not the Soliton, interpoles or brush advancement.

JR


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## Qer (May 7, 2008)

JRoque said:


> Hi. If I'm not mistaking, you need a Sepex or PM motor to get regen out a DC machine so it's not the Soliton, interpoles or brush advancement.


Yes, you are mistaken.

A series wound motor can regen which for example Zapi H2 can do. The problem with series wound motors in regen is that they're instable and thus very hard to control in regen mode (something PM or SepEx aren't), which is why we haven't started to work on it yet (lots of other things to do as it is). It's in the todo-pile but the only way it's gonna end up in the Solitons is if we find the time to test it thoroughly AND we deem it stable and safe enough to be used in traffic. If we find out that there's risks with it (either for personal safety reasons or controllers blowing up) it won't be released, so don't hold your breath.

Oh, and if I remember correctly it's the S1's that has the hardware for possibly being able to regen, the Juniors will never be able to no matter what since they lack the boost-transistor.


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## coulombKid (Jan 10, 2009)

I've got and old P & H tool room motor generator welder. A 15 Hp AC 3-phase motor spins a DC generator. The generator has four brush banks on the commutator. The brush assembly is controlled by a lever the weldor can rotate up to 90 degrees for current control. I'm not sure where the brushes would have to be moved for the generator to be used as a motor. Back before Woodstock we used to have to "motorize" rebuilt automotive generators to impart the correct residual magnetism in the field poles. They would spin on 12 volts but slowly. With residual magnetism they could start generating without external excitation. One time I dropped my welder on concrete and it quit generating. I had to hook up a 12 volt battery with a 15 amp fuse to its leads to re-magnetize it so it would generate. I had to do it twice because the first time I did it backwards.
I've got a 10 Hp 3-phase motor on my air compressor and a 2 cylinder Wisconsin ICE. When running on gas I can switch in motor run capacitors on the 3-phase motor and generated AC because the old GE motor built in 1955 has enough residual magnetism to start generating, you guessed it, without external excitation. I had to center-tap the windings and put on three stages of capacitive excitation to make a controllable 125 VAC three phase field generator out of it. This home built induction generator has been running lights and power tools for years now. The mechanical governor in the ICE holds it close enough to 60 Hz for my purposes. I suspect that a DC traction motor would need an overly complex brush plate assembly to do controlled regen. Sep-ex would be much easier to do without a malfunction burning everything up.


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