# Controller for 180VDC sepex motor?



## Clipper (Jan 30, 2011)

Can anyone recommend a motor controller for a GE 180VDC seperately-excited EV traction motor? Max momentary amp draw observed is about 300 on steep hills. I'd prefer a 1000-amp controller.

Max voltage is about 215.

Everything I'm finding has too low a voltage rating, or is for series-wound motors...frustrating!


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## DavidDymaxion (Dec 1, 2008)

Most sepex controllers are low power, like 60 kW or less. This is not a recommendation for or against, but Kelly has a 144 kW nominal sepex controller:

http://kellycontroller.com/hse141011000a144vsep-ex-with-regen-p-903.html

If you decide to get one please post about your results. I too have a sepex and I'm considering getting one. My dream is Zilla levels of power, but for sepex I think this is the highest spec power you can get.


Clipper said:


> Can anyone recommend a motor controller for a GE 180VDC seperately-excited EV traction motor? Max momentary amp draw observed is about 300 on steep hills. I'd prefer a 1000-amp controller.
> 
> Max voltage is about 215.
> 
> Everything I'm finding has too low a voltage rating, or is for series-wound motors...frustrating!


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## Clipper (Jan 30, 2011)

Hi, David,

Thanks for the quick response...but this controller is rated at 144 volts...I am running as much as 215 fully charged...180 nominal. Won't that fry something?

Thanks...


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## DavidDymaxion (Dec 1, 2008)

Yep, sadly, it's not spec'd for that much voltage, but it is the most powerful sepex controller that I'm aware of. The specs do say to not exceed 180 Volts, so you might be able to go a bit higher than 144 V. Don't forget your Voltage will rise during regen. Which controller did you use before?


Clipper said:


> Hi, David,
> 
> Thanks for the quick response...but this controller is rated at 144 volts...I am running as much as 215 fully charged...180 nominal. Won't that fry something?
> 
> Thanks...


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## Clipper (Jan 30, 2011)

DavidDymaxion said:


> Which controller did you use before?


It is a '93 Dodge TEVan; it has NiFe batteries and the controller is built-in. I am working with the original GE designer of the controller, a fellow named Bill Reynolds, to get it fixed, but I am trying to explore my options. I *do* have ALL the wiring diagrams for it (including the logic card) so I may end up trying to reverse-engineer it. I may also end up just removing a couple of batteries and lowering the voltage, or replacing both the motor and controller. I'd like to keep it as original as possible, but...like I said, I'm exploring my options...I'd rather have it running and reliable than original. I understand that GE might make a forklift controller that'll do...but I can't seem to find it online....


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## DawidvC (Feb 14, 2010)

PM both Tesseract and Qer and ask them to please stop work on all their frivolous ideas like sol jr., big sol and sol 3, and start working on a sepex soliton right now!

Their have been a few people looking for a decent sepex controller. For a higher voltage solution, try a Soliton 1. Use a dual pot setup, and hook the other pot to a smaller controller, that can exceed your field current. The motor will now behave somewhat like a series motor, and you will lose some torque at higher revolutions. As long as the smaller of the controllers can handle the pack voltage, this should be workable.

If you do not want to do all that, you can also use a Open Revolt controller. You would need to modify the design to support igbt's and a second pwm, but I think it might be do-able. This way you can even get some regen out of it. If you are serious I can help a little bit with the design and software.

regards
Dawid


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## pm_dawn (Sep 14, 2009)

This is for the GMC G-van.....

http://www.coopercontrols.co.uk/components/motors.htm

might work for you also.

I don't know if the Dodge TEVan has the same internals as the G-Van.

But it might be worth a try.....

I have been looking for one aswell......

I know Chennic has some 156V Sepex on their website, but I sent mail to ask for prices but got a really strange answer So i guess they aren't ready with the prototyps yet.

If you can find a controller from a PSA (Peugeot Partner or Citroen Berlingo) car from europe, they use 162 ish volts in their Sepex Leroy Somer setup but could probably work up to 200v they use IGBTs in thier controllers.

Renault used 114v nominial in their Sepex ABB setup, but they can be run up to 148v max.

But the Cooper is IGBT and should be most suitable for your voltage.

I would love to see a Solition SepEx from evNetics But i guess I will wait in vain.

There is a Open Revolt AC/SR/SepEx controller in the works that could be fitted with proper IGBTs to drive such a motor, you could check that up.


Regards
/Per


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## Clipper (Jan 30, 2011)

Found them. Thanks!

--Clipper


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## Weisheimer (May 11, 2009)

Clipper said:


> It is a '93 Dodge TEVan; it has NiFe batteries and the controller is built-in. I am working with the original GE designer of the controller, a fellow named Bill Reynolds, to get it fixed, but I am trying to explore my options. I *do* have ALL the wiring diagrams for it (including the logic card) so I may end up trying to reverse-engineer it. I may also end up just removing a couple of batteries and lowering the voltage, or replacing both the motor and controller. I'd like to keep it as original as possible, but...like I said, I'm exploring my options...I'd rather have it running and reliable than original. I understand that GE might make a forklift controller that'll do...but I can't seem to find it online....


Clipper,

Rod Hower had one of these TEVans and was involved in the design as well while at GE.
He is active on the EV Tech list (evtech.org) and also the EVDL.
I have his e-mail address so pm me if you are interested in that angle.

You said that you "found it"

What is it?


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## Clipper (Jan 30, 2011)

Weisheimer said:


> Clipper,
> 
> Rod Hower had one of these TEVans and was involved in the design as well while at GE.
> He is active on the EV Tech list (evtech.org) and also the EVDL.
> ...


Hi,
Thanks...I spoke with Rod on the EVDL...there's also a fellow named Bill Reynolds I'm working with who just retired...he used to do the MCU design and testing for the TEVan. I'll be pulling the logic card and sending it to him. He thinks the IGBT's may have smoked, and took the gate circuits on the logic card with them.

From what I've gathered, Rod worked more on the charger, (i.e. wrote the software for it) and Bill worked more on the controller.

"Found them"...I had originally posted that I couldn't find the controllers on the recommended webpage, but I hadn't read it carefully enough. Couldn't delete my post!


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## Weisheimer (May 11, 2009)

Heck, I thought I was the only one who couldn't get rid of my errors!

It sounds like you've gotten some good traction on finding a solution.
Please keep us posted on your results and what you learn.

There are quite a few SepEx motors out there and there is precious little for them in the way of controllers.


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## Clipper (Jan 30, 2011)

*Re: Rimshot...!*



Weisheimer said:


> It sounds like you've gotten some *good traction* on finding a solution.


Rimshot....! No pun intended, huh? 



Weisheimer said:


> Please keep us posted on your results and what you learn.
> 
> There are quite a few SepEx motors out there and there is precious little for them in the way of controllers.


Wahoo!

I just got off the phone with a fellow named Larry Machak at American Traction Systems in Florida:

http://www.americantraction.com/contact/sales_service_directory/
http://www.americantractionsystems.com/index.php/products/custom/

They do SepEx controllers for the hard-rock mining industry that are usually 120VDC and 240VDC...he says they've done road vehicles, including a land speed record holder, and mods like this before, and doesn't think it's a big deal. He's going to email me info and pricing.

Yippee! My first ray of hope. When two-dozen people in the motor controller industry tell you over two weeks that "no one does those kind of controllers anymore," you get a little discouraged, you know?


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## Linukas (Feb 22, 2011)

Hello,

there are small company, but they make quite powerful Sepex motor controlers, more info you can find:
http://www.elektromotus.lt/en/production 

Best regards,
Linas


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## major (Apr 4, 2008)

*Re: Rimshot...!*



Clipper said:


> http://www.americantraction.com/contact/sales_service_directory/
> http://www.americantractionsystems.com/index.php/products/custom/
> 
> They do SepEx controllers for the hard-rock mining industry that are usually 120VDC and 240VDC...he says they've done road vehicles, including a land speed record holder, and mods like this before, and doesn't think it's a big deal. He's going to email me info and pricing.


Good company. You'd better be sitting down when you see their price 

I'm interested in what they say. Good luck.


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## pm_dawn (Sep 14, 2009)

I found Saminco

http://samincoinc.com/index.php/products/mining/traction_drives/

They have some mining drives.

Otherwise you could perhaps up the voltage a bit and go for a AC-DC SepEx stationary drive.
Like this......

http://www.driveswarehouse.com/Drives/DC+Drives/Regen.(D),+3+Phase/D4Q1-2000-1.html

Or find something else at that site.
Or just wait for the Open Revolt AC/SR/Sepex at:

http://ecomodder.com/forum/showthre...-3-phase-inverter-ac-controller-10839-49.html

Regards
/Per


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## DavidDymaxion (Dec 1, 2008)

*Re: Rimshot...!*

Please do let us know what you find out. Kelly has a 144V 1000A sepex listed on their page for ~$1900.


Clipper said:


> Rimshot....! No pun intended, huh?
> 
> Wahoo!
> 
> ...


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## DawidvC (Feb 14, 2010)

pm_dawn said:


> I f
> Or just wait for the Open Revolt AC/SR/Sepex at:
> 
> http://ecomodder.com/forum/showthre...-3-phase-inverter-ac-controller-10839-49.html
> ...



That SR controller needs some work before it will run a sepex. Any volunteers?

Maybe we should just do it Army-style?
All electrical Engineers and Embedded Developers, One step Forward!!! 

I will be looking at it in more detail this weekend, and will report back. I know there are a number of people with sepex motors, There is a definite need for a sepex controller, so if anybody else is willing to help, please!

Dawid


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## pm_dawn (Sep 14, 2009)

I have a couple of IGBTs that would love to do some work...

But I'm no EE i'm more of the CS person.
But I have a Large ABB sepex that just longs for some heavy duty Controller to make it launch 

I have two Dual 800a IGBT and some smaller IGBTs for the field.
But I need a good driver for them to connect it to the Control card.
And some really good caps......

Does the Open Revolt AC/SR/SepEx have voltage sense on the output side(motor side) and on the input side(battery side) ?

That would probably be needed to have a reliable field reduction and also for the Regen to limit pack voltage.

I have batteries and stuff to set up a testset.
Need to borrow a scope though. But we've got one a t work that I can borrow.

I would love to contribute.

Regards
/Per


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## Tesseract (Sep 27, 2008)

DawidvC said:


> PM both Tesseract and Qer and ask them to please stop work on all their frivolous ideas like sol jr., big sol and sol 3, and start working on a sepex soliton right now!


How do you suggest we handle the issue that every SepEx motor needs a unique field map? How do we allow regen to occur when there is a gross mismatch between pack voltage and nominal armature voltage, especially if the motor doesn't have interpoles?

Finally, how do we justify the higher cost of the SepEx controller (and more complicated software needed to manage it) when an AC inverter isn't much more expensive and has less issues overall to deal with in implementation?

In other words, a good high-power SepEx controller isn't much less expensive than an AC inverter. Since the EV world is slowly, but inexorably, moving towards AC it seems making a SepEx controller would be a step backwards, no?


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## Jan (Oct 5, 2009)

Tesseract said:


> ....Since the EV world is slowly, but inexorably, moving towards AC it seems making a SepEx controller would be a step backwards, no?


Eh.. So.. When is this Solitonac inverter available? Or is Qer still busy hunting camels?


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## Tesseract (Sep 27, 2008)

Jan said:


> Eh.. So.. When is this Solitonac inverter available? Or is Qer still busy hunting camels?


WTF is this supposed to mean?


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## DavidDymaxion (Dec 1, 2008)

Tesseract, right you are there are challenges. I agree that a high power sepex is a tough business argument for multiple reasons.

A different thought is a sepex controller might make a good business case for an entry level controller. The basic idea is a cheap controller with 100 hp and regen. Here are some more details for the idea: Design it for just one brand of motor. See if that motor builder will advertise/sell your controller. Require anyone else to ship you their motor to tune the parameters. Anyone else is at their own risk and no warranty. Design it to work with an automatic transmission. Just let it idle. Have just enough silicon to control about 50 Amps for the field, and do the armature with a contactor. You could spin up with motor with the 50 Amps first, and then switch the contactor on to minimize the jerk and arc. Have some control for the automatic transmission that would delay shifts (rev the motor high), and unlock the torque converter for idling and shifts. You'd lose the advantages of starting from 0 rpm, and regen below ~20 mph, but that's how gas cars work now and would be a reasonable compromise if the controller were much lower cost. Yes, it would be a bit less efficient in traffic with the idling, but regen would help ameliorate that difference.

FWIW, my homebrew 48V sepex controller was about $500 and old school (like 100 years old) technology. The good is it was cheap, works reasonable well at city speeds, and has prodigious amounts of regen. The bad news is it burned up (need to fan cool it!), has touchy gas pedal control (sudden lift can equal skidding, and too much pedal too soon = high current draw but less acceleration). The concept does not scale up in voltage easily.


Tesseract said:


> How do you suggest we handle the issue that every SepEx motor needs a unique field map? How do we allow regen to occur when there is a gross mismatch between pack voltage and nominal armature voltage, especially if the motor doesn't have interpoles?
> 
> Finally, how do we justify the higher cost of the SepEx controller (and more complicated software needed to manage it) when an AC inverter isn't much more expensive and has less issues overall to deal with in implementation?
> 
> In other words, a good high-power SepEx controller isn't much less expensive than an AC inverter. Since the EV world is slowly, but inexorably, moving towards AC it seems making a SepEx controller would be a step backwards, no?


Perhaps he thinks you are taking "Walk a mile for a Camel" to an extreme?


Jan said:


> Eh.. So.. When is this Solitonac inverter available? Or is Qer still busy hunting camels?
> 
> 
> Tesseract said:
> ...


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## GizmoEV (Nov 28, 2009)

Tesseract said:


> How do you suggest we handle the issue that every SepEx motor needs a unique field map? How do we allow regen to occur when there is a gross mismatch between pack voltage and nominal armature voltage, especially if the motor doesn't have interpoles?


Does Sevcon get away with only having parameters for field resistance and armature resistance because their controllers are only for <100V? If so, that may explain why there aren't many SepEx controllers for higher voltages.


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## Tesseract (Sep 27, 2008)

DavidDymaxion said:


> ...The basic idea is a cheap controller with 100 hp and regen. Here are some more details for the idea: Design it for just one brand of motor. See if that motor builder will advertise/sell your controller.


Kostov would be the obvious choice - certainly can't design the controller around a surplus motor./




DavidDymaxion said:


> Require anyone else to ship you their motor to tune the parameters.


We would have to connect every motor sent in to our dyno to generate a field map for it. Needless to say, that might not be feasible, especially if the motor doesn't bolt right up to our dyno.



DavidDymaxion said:


> Design it to work with an automatic transmission. Just let it idle.


Can't do regen with many automatics, so why use a SepEx motor?



DavidDymaxion said:


> Have just enough silicon to control about 50 Amps for the field, and do the armature with a contactor.


This is way too primitive. There are just slight advantages to a SepEx motor over a series motor of the same size; this control scheme tosses out all of them.

And can you really see us making something so... well... crude? Not really our style...


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## Tesseract (Sep 27, 2008)

GizmoEV said:


> Does Sevcon get away with only having parameters for field resistance and armature resistance because their controllers are only for <100V? If so, that may explain why there aren't many SepEx controllers for higher voltages.


I can't really speak for Sevcon, and I have no experience with their products, either. However, they are made for forklifts, no? Not exactly the same application as a road-going vehicle.

Even still, measuring armature resistance would be... challenging. It's usually a fraction of an Ohm and most multimeters - even good ones - struggle measuring such low values of resistance.

That said, I can't see how plugging in the armature and field resistance would be at all helpful. I would think the minimum data needed would be the S2-60 field and armature currents, and the recommended armature voltage.


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## GizmoEV (Nov 28, 2009)

On my D&D 6.7" motor the armature resistance is 11 mOhm and the field resistance is 0.76 Ohm. I presume that D&D provided this information. I know I just don't want to lose it! The Sevcon also has three parameters each for armature and field current. A Low, Mid, and High value. This might be what they do for their "map" of the motor. There is a field shunt and an armature shunt in the controller so I don't know why they need the resistances except that they can control the speed without any external sensors. Maybe they use that some how to indirectly calculate the speed.


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## DawidvC (Feb 14, 2010)

GizmoEV said:


> There is a field shunt and an armature shunt in the controller so I don't know why they need the resistances except that they can control the speed without any external sensors. Maybe they use that some how to indirectly calculate the speed.


The field shunt is needed because you need current control to do field weakening. The Armature shunt is for the armature current control loop.

BTW, Tesseract, most modern DC Drives do have a way of measuring the armature resistance. I don't have the details with me now, but will have it later today.

In normal shunt motors, you only need to know where the 'knee' is as far as the field control is concerned. I am not familiar with sepex traction motors, but what I have read thus far suggest that the most common control method just saturate the field while pulling high amps at low speed, and thereafter it is controlled the same as a normal shunt motor. It would seem then that 3 control points may be able to control the field.

Regards
Dawid


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## GizmoEV (Nov 28, 2009)

DawidvC said:


> The field shunt is needed because you need current control to do field weakening. The Armature shunt is for the armature current control loop.


I understand that. That wasn't my question. My question is why does the field resistance need to be know by the controller when it has a shunt to measure current?

According to the Sevcon manual the controller controls the field current based on the armature current. As the armature current drops the field current is lowered. I believe it does a linear interpolation between the three current values entered into the controller.


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## pm_dawn (Sep 14, 2009)

I think that it would be possible to do pretty much of a Sepex controller.
Altough it would need to be very configurable.

In my car I have a ABB SepEx with industrial heritage but slightly revised for road application. It has rpm sensor that feeds the controller with speed info. From that info the Field is adjusted in combination with the throttle info. 

It has interpoles and uses a two stage field map.
the field follows the Armature up to a certain rpm (base rpm without field reduction) and the the field is cut by 3/4 to allow the motor to over rev almost 4 times.

Now that is all well if you have a fixed voltage to run the controller off. But I would like to get more power from the motor and do that both by uping the current and the voltage, but since this controller does not have a other than the rpm to control the field, uping the voltage does not give much effect, the controller cuts the torque at the same rpm even if I would be able to produce 1000rpm more at the same torque due to the the higher voltage.

So I would like to have a controller that senses the output voltage(like the Sol1 and SJR does) and form that and perhaps a speed delta adjust the field linear down to its minimum by that achiving the most torque at a wider range of rpm.

I could see a problem with regen if you pack voltage is much higher than the motor voltage set. But I guess that one would have to take that into account when mating the motor with a controller and a pack.

There are many parameters here but there would be possible to get the controller to do a self adjust diagnose within some initial parameters based on a light load(spinning the wheels on stands?) and doing some calculations from the acceleration and rpm and the different currents.

But of course if you start playing with field reduction and regen you could easily end up in scenarios where the controller could be faced with voltage levels 2-4x the base voltage so if you have a motor rated for 200v you could end up getting 800v out of it if you apply to much field at regen. The control loop would probably need to be very fast and accurate to protect both the controller and the pack.

Best Regards
/Per


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## Qer (May 7, 2008)

Jan said:


> Or is Qer still busy hunting camels?


Wtf......?


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## DawidvC (Feb 14, 2010)

I know from previous post on this subject that one of the concerns with sepex motors are their much lower internal inductance compared with series motors. I have been thinking this over for a while, and have a proposition: If we were to use 3 halfbridges, and switch them in sequence through their own individual inductors, it will solve the inductance problem. It would also mean lower duty cycles and smoother motor control. If we run each halfbridge at 5kHz, the motor would in effect see 15kHz. I agree that the inner current control loop will need to run at >15kHz. Running the field on oversized igbt's at the same frequency would ease the software development. That would mean we need a minimum of 7 pwm's (if we use some external components) and a maximum of 10 (overdesigning).

The most basic control system for sepex motors is to increase field current in proportion with armature current. I believe a thorough search will be able to turn up better schemes, but for getting a working system this is the easiest.

For determining the basic resistance of the armature, climping the motor and injecting a predetermined current and measuring the resultant bemf should work. The inductance can be measured in a similar way, as we know the switching frequency. Similarly, by injecting a current into the field, the basic field values can be established.

During regen, the controller will behave as a boost controller. Here the inductors will come in handy to help regulating the regen. However, too much inductance can create a problem if the sepex motor is in reality compound wound, so the choice of inductance need to be considered carefully. Using 3 switches we can make the flow of current to the battery smoother.







This is a simplified version of the power circuit.

Any comments please

Dawid


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## Jan (Oct 5, 2009)

Qer said:


> Wtf......?


Never mind

http://www.diyelectriccar.com/forums/showpost.php?p=220576&postcount=10


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## Qer (May 7, 2008)

Jan said:


> Never mind
> 
> http://www.diyelectriccar.com/forums/showpost.php?p=220576&postcount=10


Oooo. Sneaky. I'd totally forgot about that.


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## Tesseract (Sep 27, 2008)

DawidvC said:


> ...we need a minimum of 7 pwm's (if we use some external components) and a maximum of 10 (overdesigning).


Yeah... umm... remember me saying you might as well make an inverter?



DawidvC said:


> The most basic control system for sepex motors is to increase field current in proportion with armature current. I believe a thorough search will be able to turn up better schemes, but for getting a working system this is the easiest.


Nope, the simplest control scheme is to apply a fixed current to the SepEx field(ie - like a PM motor). You can get much of the benefit of a SepEx motor with this scheme without a lot of extra hassle. 



DawidvC said:


> For determining the basic resistance of the armature, climping the motor and injecting a predetermined current and measuring the resultant bemf should work. The inductance can be measured in a similar way, as we know the switching frequency. Similarly, by injecting a current into the field, the basic field values can be established.


The armature resistance is only relevant if you want to regulate speed without a tachometer (ie - for "IR Compensation").

You can't really measure armature inductance while the armature is stationary, either, because the brushes short several turns together - the apparent inductance is much higher when the armature is rotating, in other words. You could instead measure the percent of the armature current that is AC ripple and calculate the inductance from that though, once again, that isn't really relevant for torque control (it would be nice, I'll grant you, for protecting the controller against too high a dI/dt).

Oh, and you might want to do some calculations on the inductors you'd need to implement your scheme. Big and costly are two adjectives that come to mind...


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## Tesseract (Sep 27, 2008)

DawidvC said:


> BTW, Tesseract, most modern DC Drives do have a way of measuring the armature resistance. I don't have the details with me now, but will have it later today.


Yep, but if the controller requires you to enter the resistance value first in order to operate then you are kind of stuck, eh?


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## DavidDymaxion (Dec 1, 2008)

Every automatic I have driven (hundreds of them) you can downshift for engine braking -- that could be regen in an electric. With a locked torque converter you could get even more regen. With control of the shifts you could keep the rpm high, so even more regen than a human that fails to downshift.

There is certainly nothing wrong with aiming for the high end market like the Soliton controllers do. Yes, a cheapy sepex like I describe would be crude compared to a current Soliton or AC controller, but it would be similar to the gas engine (have to start it, it has to idle, detectable shift points, less power...) and much lower in price.

1/2 the price and regen is more than a slight advantage. 


Tesseract said:


> ... Can't do regen with many automatics, so why use a SepEx motor?
> 
> This is way too primitive. There are just slight advantages to a SepEx motor over a series motor of the same size; this control scheme tosses out all of them.
> 
> And can you really see us making something so... well... crude? Not really our style...


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## Sciencemander (May 10, 2010)

Hi, 
My name is Sten from Petaluma California.
I built CO2 les on page 12.
I am looking at a '93 Dodge Tevan with Sepex motor, Saft Nicads and 
a non op charger controller. How long do the Nicads last?
Who can lend a hand with the charger/controller?
Please advise and thanks


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## pm_dawn (Sep 14, 2009)

Some of the Saft NiCads tend to last almost forever.
I know a guy here in sweden with 100000km on his Saft NiCads.
Over ten years of use and still going strong.
That is if you take care of them. like watering them in a correct way, and keep them clean and cool.

Regards
/Per


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## DIYguy (Sep 18, 2008)

What about using an industrial drive like an Allen Bradley 1395 and trashing the rectifier part? .... like what Eric Tischer (sp?) did with his industrial AC drive? I think these can be used with a variety of field requirements.


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