# Sevcon AC controllers



## JRP3 (Mar 7, 2008)

These look interesting from Sevcon, I've never seen them before. AC controllers available from 80-300 volts up to 800 amp peak for one minute;
http://www.sevcon.com/pages/gpac.html


> The Gen4 controllers are designed to control either AC Asynchronous motors or PMAC Synchronous motors. This feature allows users to select optimal motor solutions for any application. Both UVW and encoder AB inputs are provided for maximum flexibility.


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## Bowser330 (Jun 15, 2008)

JRP3 said:


> These look interesting from Sevcon, I've never seen them before. AC controllers available from 80-300 volts up to 800 amp peak for one minute;
> http://www.sevcon.com/pages/gpac.html
> ​


GOOD FIND!

Now what motor to use!

Could we use these controllers for the Siemens Ford Motor? 
Or maybe the smaller Electro motor sport AC motors?


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## MJ Monterey (Aug 20, 2009)

If I am reading and interpreting the numbers correctly, the larger controller should be able to push a mid size car or small pickup down the road at sustained freeway speeds?

And with 800 amps, Assuming appropriate gearing, it should have respectable performance with a 3000 pound vehicle?


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## crap (Dec 5, 2009)

If the price is within reason, these controllers are awesome...
Although I would really like to know the maximum electrical RPM and some other stuff. Also it doesn't seem to say if it has regen braking or not. The datasheet is quite poor...


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## frodus (Apr 12, 2008)

wow, good find, they didn't have these a few months ago when I looked, thats for sure!!!

I'm asking for pricing.


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## JRP3 (Mar 7, 2008)

These might be used with the HPG/HPEVS motors to take them to higher voltage and amperage. HPEVS told me they can wind their motors for 200 volts max but I'm not sure how high their stock motors can go. Sevcon claims 100kw on the biggest drive. Maybe these can be used with some of the lighter aluminum frame industrial motors like those from ABB and ABM.


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## frodus (Apr 12, 2008)

they're rewound leeson motors.... wondering if the STOCK 240VAC leeson motors will work with the standard 240V controller.....

either way, HPGC said they just need a controller and they can push the limits of the curtis controllers out the window!

Smaller cables, much easier to work with.


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## JRP3 (Mar 7, 2008)

frodus said:


> either way, HPGC said they just need a controller and they can push the limits of the curtis controllers out the window!


A few months ago they said they were working with a controller builder, I think on a 144 volt controller. I haven't heard anything more since then.


> Smaller cables, much easier to work with.


Only if you intend to lower the amps, but yes you could go higher voltage with lower amps. Or higher voltage with higher amps for the win


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## MJ Monterey (Aug 20, 2009)

JRP3 said:


> Only if you intend to lower the amps, but yes you could go higher voltage with lower amps. Or higher voltage with higher amps for the win


I like the way you think!


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## Zak650 (Sep 20, 2008)

One thing that is interesting about the Gen 4 controllers is that they can be coupled together one "slave" getting it's driving parameters form the "master". With this arrangement you have an "electronic differential" one motor driving one wheel with the (turning / phase frequency) difference being driven or adjusted by different inputs.

Zak


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## etischer (Jun 16, 2008)

Zak650 said:


> One thing that is interesting about the Gen 4 controllers is that they can be coupled together one "slave" getting it's driving parameters form the "master". With this arrangement you have an "electronic differential" one motor driving one wheel with the (turning / phase frequency) difference being driven or adjusted by different inputs.
> 
> Zak


Actually I think a master / slave "electronic line shafting" would be the opposite of a differential, more like a traction control. The motors would eventually accumulate a large position error, and begin fighting each other just like a 4x4 would with a locked center differential. 

If each motor is putting out the same torque, this would be the equivelant of an open differential.


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## Zak650 (Sep 20, 2008)

syncronos motors do not have slip therefore the outside wheel would have to be driven with more cycles to accomadate the longer distance traveled. The electronic differential can be driven via a pot on the steering wheel so the outer motor controller is told to feed higher frequency or the master/slave system can be set up to adjust the frequency of the two controllers seperately to accomplish equal amperage thru each controller. This doesn't need to happen with DC systems and to less of an extent with induction motor systems since they have slip.

Zak


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## etischer (Jun 16, 2008)

Zak650 said:


> syncronos motors do not have slip therefore the outside wheel would have to be driven with more cycles to accomadate the longer distance traveled. The electronic differential can be driven via a pot on the steering wheel so the outer motor controller is told to feed higher frequency or the master/slave system can be set up to adjust the frequency of the two controllers seperately to accomplish equal amperage thru each controller. This doesn't need to happen with DC systems and to less of an extent with induction motor systems since they have slip.
> 
> Zak


If each motor has the ablity to control torque, this is all you need for an electronic differential. A differential puts equal torque at each wheel. 

Running a motor in a pure speed or position mode is not practical for an EV. Trying to predict how much extra distance each wheel needs to travel to maintain the same angular position with the other wheel isn't feasible.


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## Zak650 (Sep 20, 2008)

I believe Segways are controlled in this manner with very tight turning radii and smoothly enough to operate on two wheels only.


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## MJ Monterey (Aug 20, 2009)

Segways drive the motors as a direction control mechanism getting feedback from the operator. Powered wheel chairs funtion the same. Most move slow enough that people will not die if the driver feedback system hiccups.

Why would you want to power two different wheels this way in a car? Wouldn't it make more sense to stack the motors and power one motor during normal operation and then bring the second one on when extra power is needed?


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## CroDriver (Jan 8, 2009)

My Diesel powered BMW X6 has a active differential. It distributes more torque to the outer wheel in a curve 

http://www.youtube.com/watch?v=8g11jPzjuQI&feature=player_embedded

It usually distributes 30% to the front wheels and 70% to the rear but in some extreme situations even 100% can go to one wheel.

I think that two electric motors on one wheel would do fine without any additional controlling in curves because they allow some slip, don't they?

On a straight line the controlling would probably be necessary.


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## tomofreno (Mar 3, 2009)

Yeah, good find JRP3! HPGC also told me around a month ago they were working with another supplier on a higher voltage controller, didn't say who. I think the AC50 could be pushed to higher continuous power as is. The motor remains much cooler than the Curtis controller, and an axial fan could be added in place of the rear shroud to give more cooling of the rotor. I would think you could run it at maybe low to mid 20's HP continous then, which would be enough for a 3000lb vehicle to run at 60-65mph continous.


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## Kelmark (Oct 26, 2009)

frodus said:


> wow, good find, they didn't have these a few months ago when I looked, thats for sure!!!
> 
> I'm asking for pricing.


Any luck on pricing? I am also looking at using a Sevcon controller with an AC-50 motor. If the price is comperable.


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## frodus (Apr 12, 2008)

nope, its still not readily available. I emailed them as a distributor, still nothing back.

They did send me stuff on the other AC stuff (below 96V), but nothing on the new controllers.


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## Kelmark (Oct 26, 2009)

frodus said:


> nope, its still not readily available. I emailed them as a distributor, still nothing back.
> 
> They did send me stuff on the other AC stuff (below 96V), but nothing on the new controllers.


Hello Frodus,

Do you know if the controller below would work with the AC-50? It has the cooling system built in and similar compared to Curtis, it is listed at 80V nominal instead of 96V. On the other hand, it has 600 amps for 1min. And it might be able to handle a slightly higher voltage comparable to the Curtis? 

Also I could not find, continues amp rating, for the Curtis controller but the Sevcon is rated for 240 cont. which should be enough to handle highway speeds without getting hot I would think. Which has been an issue for some that have installed this system. 

I am trying to compare prices now, and I thought you might be able to get this or at least get a price as a distributor.

Sevcon “espAC” 80V Single Traction 600/240 Amp controller with the fan cooling http://www.sevcon.com/pages/espac.html

Respectfully,

Jacob Blake


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## frodus (Apr 12, 2008)

I can't even get them to get me the manual or full specs...... They responded only with pricing on the gen4 stuff.


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## crap (Dec 5, 2009)

Just bringing this up since nobody else has, but 800 amps and 240 volts should add up to 192kW. Suprises me that sevcon newer printed this number but only say "up to 100kW". Could it be that 800 amps only refers to max motor amps, and the controller is unable to maintain these amps at increased motor voltage?

Hoping someboy will confirm that this can actually deliver over 190kW, that would be awesome...


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## CroDriver (Jan 8, 2009)

crap said:


> Just bringing this up since nobody else has, but 800 amps and 240 volts should add up to 192kW. Suprises me that sevcon newer printed this number but only say "up to 100kW". Could it be that 800 amps only refers to max motor amps, and the controller is unable to maintain these amps at increased motor voltage?
> 
> Hoping someboy will confirm that this can actually deliver over 190kW, that would be awesome...


Even if it really does handle 240V and 800 Amps, the power could never be 190kW in real life because the voltage of the battery pack would drop at least 20% under heavy loads


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## JRP3 (Mar 7, 2008)

No one can even confirm these controllers even exist, so I doubt we'll get any confirmation of the ratings.


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## crap (Dec 5, 2009)

CroDriver said:


> Even if it really does handle 240V and 800 Amps, the power could never be 190kW in real life because the voltage of the battery pack would drop at least 20% under heavy loads


 
Obviously, but then again you could probably stretch the packs nominal voltage a bit higher, and the 800 amp rating is for one full minute. Sevcon usually has a slightly higher 10 second rating aswell. And even if none of that is true and you do have to take away 20% it still adds up to about 154kW, which is still more than 100kW and still great.

oh well, patience is a virtue so let's wait and see...


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## few2many (Jun 23, 2009)

Hey frodus, what was the pricing on the gen 4 suff?


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## frodus (Apr 12, 2008)

they gave me dealer pricing, so I can't really say.....but It was around the same price as the curtis stuff.


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## RoughRider (Aug 14, 2008)

OK...same price as the Curtis, but much *more power...48kW cont. *

are this controllers generaly available to us or not?


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## frodus (Apr 12, 2008)

Once I got pricing, they never really responded back.

Good luck.


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## solo (Oct 11, 2010)

I see they have different sizes of gen4 controllers. What's the MSRP for each?


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## frodus (Apr 12, 2008)

call them or a distributor, i only got initial OEM pricing, quite a while ago.


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## todayican (Jul 31, 2008)

Not higher voltage then the ac 50 but its worth posting 
http://www.electricmotorsport.com/store/ems_ev_parts_controllers_sevcon_gen4_72-80_550.php

900 smackers for the programmer thingee :-(


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## JRP3 (Mar 7, 2008)

650 peak amps is nice, but the 80V max is not.


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## todayican (Jul 31, 2008)

It looks a smidge better with 116 total voltage range, 31 cells maybe


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## frodus (Apr 12, 2008)

the 1231-7501 goes to 130V max

but its a helluva lot cheaper than the curtis.... except you'd need a programmer.


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## JRP3 (Mar 7, 2008)

What does a Curtis 1238-75 cost on it's own anyway? The Sevcon programmer is more ridiculously prices than the Curtis 1311, or the software and I didn't think that was possible.


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## todayican (Jul 31, 2008)

This controller is looking good for my app, I wonder which of the distrubutors would do a "rental" of the programmer, or just code it at their shop with theirs?

The comparable Kelly is 999 bldc 72v 700 "Kelly amps" not too far off.


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## frodus (Apr 12, 2008)

JRP3 said:


> What does a Curtis 1238-75 cost on it's own anyway? The Sevcon programmer is more ridiculously prices than the Curtis 1311, or the software and I didn't think that was possible.


oh, like $1800, somewhere around there. Thats without software in it. It needs software and configuration. The programmer we get only does configuration.


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## frodus (Apr 12, 2008)

todayican said:


> This controller is looking good for my app, I wonder which of the distrubutors would do a "rental" of the programmer, or just code it at their shop with theirs?
> 
> The comparable Kelly is 999 bldc 72v 700 "Kelly amps" not too far off.


What motor are you going to use? 

It does look like a decent controller, but the cost of that and a programmer is still pretty spendy......

wonder if they'll do a package for less.


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## todayican (Jul 31, 2008)

http://www.electricmotorsport.com/store/ems_ev_parts_motors_pmac-ds.php

I actually got a good deal on this one somewhere else, PM me and ill let you know 

Travis, Id love to hear your opinion of this motor running 96v and an 800 to 850lb, without people. (slick Aero) trike


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## frodus (Apr 12, 2008)

They say 72V max, so I won't comment other than you'd be running it out of spec. I'd ask Mars directly to see if a 96V pack is too much. Fully charged a 96V pack would be over 110V.

The curve on the motor shows only about 7kw peak. I seriously doubt it'd get to 30kw, but they're the motor experts. I'd ask for a graph proving the power output.


As far as the application, what speed will you need to get to? Fast acceleration? I'm skeptical of the performance numbers, but if they hit it, it may be a good motor for the job.


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## todayican (Jul 31, 2008)

John over at Mars said that hes confident in the peak amps and 96 should be fine, if I keep the armature under 5000, I believe the electric Motorsports folks are actually advertising it at 96v


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## frodus (Apr 12, 2008)

For me, confidence doesn't mean much. I'd ask to see proof that they can hit the 30kw number. And as far as 96V, He may be confident, but again, has it ever been tested for continuous and peak HP and torque at that voltage?

"sure, yeah, I think it'l do that" isn't enough for me.


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## crap (Dec 5, 2009)

what I really want to know is the max electric RPM, or Hz, that the sevcon controllers will handle. Have tried emailing them but it hasn't worked. Anyone who knows or can find out?


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## todayican (Jul 31, 2008)

You might hit the guys at electricmotorsport?


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## todayican (Jul 31, 2008)

I want to say, I just spent 2 hours on the phone with Mark at ThunderStruck. He took the time to go over each detail with my build with patience. and when it came time to order parts, he gave me REAL deals on the right equipment. I am super impressed!

Just sayin...


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## frodus (Apr 12, 2008)

Mark and Brian at Thunderstruck are awesome guys.


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