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Discussion Starter · #1 ·
Based on EVeryones experience with their DC motors, what improvements could you recommend to make it a more versatile piece of
equipment. Assuming the extra fancy features will just drive up the price, what would you say would be acceptable minimal
improvements that would still keep costs of production down?

I'm thinking on the splined shaft on my TransWarP9 and wondering if a spline on the aux shaft would be useful too. Should the CE
shafts be the same size as the DE shafts?

Would an adjustable brush rigging add significant flexibility to the motor? Or how about just a couple more advancement holes
drilled in the housing?

How about brass brush holders? and what brush size and grade would be best for the typical EV on the road?

I don't know if the ADC motors come with a temp. snap switch but if it does like like the WarP motors, would it be better to put
it on or near the brush rigging? Is the one on the housing useless since presumably the brush area will get hotter and is more
susceptable to heat damage? Or would it be useful to keep the housing temp snap switch in place too.

Would there be any need for higher than class H insulation? thinner laminations?, reduced air gaps?

Lifting eye bolts around the housing?, recessed pole shoe bolts?, More fan?, dyno test report with EVery motor? or at least a
representative sample at various typical operating points ie 72V, 120V, 144V, 170V, at 300A, 500A and 1000A.

I kinda think they should all come with custom graphics, flame jobs are nice, plasma jobs maybe less so ;-)

What would EVeryone's favorite factory production motor look like?

[you can say you want a smaller one, no one will make fun of you....except maybe Jim....or one of his evil quadruplets ;-P

Mike,
Anchorage, Ak.





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Discussion Starter · #2 ·
Hello Mike,

The motor you are specifying is exactly what I have and more. I been trying
to get NetGain to make there mores like the TRACTION MOTORS like GE makes.

These motors are a exact engine exchange. You can pull out the engine of a
vehicle and install it mounting to the same engine mounts and connected
right to the existing transmission that may either a manual or automatic.

When you order one of these TRACTION MOTORS, you page threw the GE DC motor
book and pick out any features you want, like the totally enclosed housing,
external fan blowers with exhaust outlets, motor mounts placements for
different type of engines that it will replace, the type of transmission it
will connect to, which uses different shape rear motor adapter plates, which
is part of the motor, not a add on.

You can specific different temperature ratings of the windings, continuous
duty ratings, single or double shaft and what diameters, key or splined with
splined large or small flanges for any different type of take offs.

The front mounting face can be rigged up to fit many type of accessory
mounting assemblies. Just transfer the original accessories that was on the
engine onto the motor.

My motor is a GE traction motor that is 11.5 inch in diameter, but is
shorter with the adapter plate mounted than a Warp 9 motor housing without
adapter plated. The Warp 9 adapter which is 2.75 inches thick, is not ideal
for my installation, because it pushes back the transmission and have to
shorten up the drive line.

The GE motor has a large output shaft diameter, where the pilot shaft
bushing is install in the end of the motor shaft. This allows for a better
alignment than having the pilot shaft bushing mounted in the motor coupler
that also pushes back the transmission.

You can also specified to have commentator poles which I have and all the
field windings are layer on insulated 1/8 inch square rods that are place
between each layer of insulation paper between the windings. This allows
for the fan blower air flow between all the windings.

The entire inside motor surface is coated with a insulation coating, even
the face of the commentator and even the motor shaft up to the bearing
surfaces. If you have this done later in a motor overhaul, make sure you
tempory bolt the field shoes in or a pattern, so there is no conductive
coating between the field shoes and the motor frame.

This internal coating should be apply until the surfaces are glass smooth,
so the brush dust can easily blow out.

The field shoes mounting bolts are recessed using a hex drive head. The
problem I had with the Warp motors, the expose hex head bolts were in the
way of the clam shell type of mounting. I had to bridge these bolt heads
with 1/4 inch square steel rods that was welded to the bottom of a wide 5
inch clam shell that was position to fit the same bolt on engine mounts that
my GE went to.

NetGain is getting close with there TransWarp motor. You can have them add
custom features you want.

Roland






----- Original Message -----
From: "Mike Willmon" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Monday, August 27, 2007 11:54 PM
Subject: [EVDL] Motor wish list


> Based on EVeryones experience with their DC motors, what improvements
> could you recommend to make it a more versatile piece of
> equipment. Assuming the extra fancy features will just drive up the
> price, what would you say would be acceptable minimal
> improvements that would still keep costs of production down?
>
> I'm thinking on the splined shaft on my TransWarP9 and wondering if a
> spline on the aux shaft would be useful too. Should the CE
> shafts be the same size as the DE shafts?
>
> Would an adjustable brush rigging add significant flexibility to the
> motor? Or how about just a couple more advancement holes
> drilled in the housing?
>
> How about brass brush holders? and what brush size and grade would be
> best for the typical EV on the road?
>
> I don't know if the ADC motors come with a temp. snap switch but if it
> does like like the WarP motors, would it be better to put
> it on or near the brush rigging? Is the one on the housing useless since
> presumably the brush area will get hotter and is more
> susceptable to heat damage? Or would it be useful to keep the housing
> temp snap switch in place too.
>
> Would there be any need for higher than class H insulation? thinner
> laminations?, reduced air gaps?
>
> Lifting eye bolts around the housing?, recessed pole shoe bolts?, More
> fan?, dyno test report with EVery motor? or at least a
> representative sample at various typical operating points ie 72V, 120V,
> 144V, 170V, at 300A, 500A and 1000A.
>
> I kinda think they should all come with custom graphics, flame jobs are
> nice, plasma jobs maybe less so ;-)
>
> What would EVeryone's favorite factory production motor look like?
>
> [you can say you want a smaller one, no one will make fun of you....except
> maybe Jim....or one of his evil quadruplets ;-P
>
> Mike,
> Anchorage, Ak.
>
>
>
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter · #3 ·
come up with a way to make them lighter without
making them weaker
--- Mike Willmon <[email protected]> wrote:

> Based on EVeryones experience with their DC motors,
> what improvements could you recommend to make it a
> more versatile piece of
> equipment. Assuming the extra fancy features will
> just drive up the price, what would you say would be
> acceptable minimal
> improvements that would still keep costs of
> production down?
>
> I'm thinking on the splined shaft on my TransWarP9
> and wondering if a spline on the aux shaft would be
> useful too. Should the CE
> shafts be the same size as the DE shafts?
>
> Would an adjustable brush rigging add significant
> flexibility to the motor? Or how about just a
> couple more advancement holes
> drilled in the housing?
>
> How about brass brush holders? and what brush size
> and grade would be best for the typical EV on the
> road?
>
> I don't know if the ADC motors come with a temp.
> snap switch but if it does like like the WarP
> motors, would it be better to put
> it on or near the brush rigging? Is the one on the
> housing useless since presumably the brush area will
> get hotter and is more
> susceptable to heat damage? Or would it be useful
> to keep the housing temp snap switch in place too.
>
> Would there be any need for higher than class H
> insulation? thinner laminations?, reduced air gaps?
>
> Lifting eye bolts around the housing?, recessed pole
> shoe bolts?, More fan?, dyno test report with EVery
> motor? or at least a
> representative sample at various typical operating
> points ie 72V, 120V, 144V, 170V, at 300A, 500A and
> 1000A.
>
> I kinda think they should all come with custom
> graphics, flame jobs are nice, plasma jobs maybe
> less so ;-)
>
> What would EVeryone's favorite factory production
> motor look like?
>
> [you can say you want a smaller one, no one will
> make fun of you....except maybe Jim....or one of his
> evil quadruplets ;-P
>
> Mike,
> Anchorage, Ak.
>
>
>
>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>




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Discussion Starter · #4 ·
I would like to see a DC motor that can do regen
without causing an explosion. I have heard
that there was a controller that supported
Regen with a Sepex motor....not sure I remember right.
I wasn't clear whether the problem was with the motor
or the controller or both or just not a match-up,
but it ought to be possible to get a solution,
perhaps with advance timing or whatever.

This is relevant for a vehicle that doesn't
warrant an AC drive system, but regen would be nice.

Some method for sensors - whether for RPM,
perhaps direction (with 3 sensors, a circuit can
tell which way it is turning)


Thanks
Seth

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Discussion Starter · #5 ·
Regen would be nice. I have a SepEx in my Gizmo with a
Sevcon controller and it does regen. In my little car
it saves a the brakes a bit. Don't know if SepEx is
not as efficient, powerful, or what or just a more
complicated controller. It seems an ideal midpoint
between Series DC and AC. I don't have much experience
to go by, however.

David
--- Seth Rothenberg <[email protected]> wrote:

>
> I would like to see a DC motor that can do regen
> without causing an explosion. I have heard
> that there was a controller that supported
> Regen with a Sepex motor....not sure I remember
> right.
> I wasn't clear whether the problem was with the
> motor
> or the controller or both or just not a match-up,
> but it ought to be possible to get a solution,
> perhaps with advance timing or whatever.
>
> This is relevant for a vehicle that doesn't
> warrant an AC drive system, but regen would be nice.
>
> Some method for sensors - whether for RPM,
> perhaps direction (with 3 sensors, a circuit can
> tell which way it is turning)
>
>
> Thanks
> Seth
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>


David D. Nelson
[email protected]



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Discussion Starter · #6 ·
Mike Willmon wrote:

> I'm thinking on the splined shaft on my TransWarP9 and
> wondering if a spline on the aux shaft would be useful too.
> Should the CE shafts be the same size as the DE shafts?

How about a male splined DE shaft that accepts a standard driveshaft
yoke (basically the TransWarp setup), and a female splined CE that
accepts the splined DE shaft of a second (or third, etc.? ;^) motor?

I think a female spline that allows the next motor to be coupled
directly and compactly to the preceding one would address a known
challenge facing users of multiple motors. If a shaft large enough to
accept the DE spline is a challenge, perhaps a male splined and
externally threaded shaft that accepts a suitable pinion flange/yoke so
that the motors could be coupled by installing a flange, u-joint and
driveshaft yoke?

> Would an adjustable brush rigging add significant flexibility
> to the motor? Or how about just a couple more advancement holes
> drilled in the housing?

I suspect that most users aren't yet sophisticated enough to take
advantage of an adjustable brush rigging.

Maybe the answer is a clearly marked holes for true neutral point and
clearly marked 'normal' advance positions for both CW and CCW rotation,
with 'normal' advance perhaps being a little different from what
ADC/Netgain ship their motors with based on what Jim H may have learned
is more appropriate for our EV use? Maybe advancement holes for
"street" and "strip" advance, if those values differ sufficiently that
the holes don't overlap?

A useful feature on an adjustable brush rigging setup might be a degree
ring/indication to allow users to clearly identify what advance their
motor is set to.

> How about brass brush holders? and what brush size and grade
> would be best for the typical EV on the road?

I suspect this is best deferred to the likes of Jim H.

> I don't know if the ADC motors come with a temp. snap switch
> but if it does like like the WarP motors, would it be better to put
> it on or near the brush rigging? Is the one on the housing
> useless since presumably the brush area will get hotter and is more
> susceptable to heat damage? Or would it be useful to keep
> the housing temp snap switch in place too.

ADCs come with the field/case temp sensor also. It is actually a useful
feature for relatively heavy, relatively low-powered street conversions
since their longer duty cycles may well show up as higher overall motor
temp rather than localised heating at the brushes.

Brush temp is typically sensed with a thermocouple embedded in one of
the brushes, which is more difficult to interface to something like the
original vehicle's temp idiot light than the snap switch.

> Would there be any need for higher than class H insulation?
> thinner laminations?, reduced air gaps?

I expect the insulation and laminations are OK. The reduced air gaps
falls into the realm of motor blueprinting. You can't reduce the air
gaps without first ensuring that the armature is trued better than
stock, but after that it might well be beneficial to shim the pole shoes
out so that all the gaps are equal and "optimal" (whatever that might
mean).

> Lifting eye bolts around the housing?, recessed pole shoe
> bolts?, More fan?, dyno test report with EVery motor? or at least a
> representative sample at various typical operating points ie
> 72V, 120V, 144V, 170V, at 300A, 500A and 1000A.

A dyno report with every motor would be sweet. I don't think lifting
eye bolts are an issue as a strap around the motor works well when using
an engine hoist.

I'd be inclined to argue for less fan. The internal fan doesn't provide
much/effective cooling at low speeds, which is where a lot of the street
use heating occurs, and drag racers often remove the fan entirely to
avoid its losses due to the short duty cycle their motors are subjected
to. Perhaps no internal fan or a minimal one and a
thermostatically-controlled external blower on the CE with a temp sensor
in the exit air flow at the DE?

Recessed pole shoe bolts would be nice (the ones on my ADC 8" are at
least partially recessed), and as we're about to discuss eye candy
aspects, I'd suggest that stainless button head socket cap screws for
the pole show bolts, installed after the case is painted, would be a
nice touch. ;^>

> I kinda think they should all come with custom graphics,
> flame jobs are nice, plasma jobs maybe less so ;-)

I think the key here is "custom", which implies to me that what may be
required of the motor is that it provide a good, properly-prepped base
on which the graphics may be applied. Buffed and anodised endbells
would be nice, and button head socket cap screws all around, of course
;^>.

I wonder what (if anything) might be possible to dress up the motor
connections? Perhaps SAE type posts to allow the use of beefy battery
clamps (perhaps gold-plated car audio types for more eye candy appeal?)
for the controller-to-motor interconnects? I'm a bit torn here, since I
prefer the use of a simple beefy solid busbar for the armature-to-field
jumper in a non-reversing setup and the stock threaded studs work well
for that.

Cheers,

Roger.

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Discussion Starter · #7 ·
How about interpoles?

They would eliminate the need to advance brushes, make regen a bit easier,
and keep arcing down at higher voltages/currents. A little extra
length/diameter/weight would be a small price to pay for a more "bullet
proof" motor. Do interpoles help improve efficiency at all?

-Adrian

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Discussion Starter · #8 ·
Adrian DeLeon wrote:

> How about interpoles?
>
> They would eliminate the need to advance brushes, make regen a bit
> easier,
> and keep arcing down at higher voltages/currents.

Just what I was going to say :) If we had more DC motors with
interpoles available, then perhaps we'd see more controllers that can
do regen with DC motors.

I don't quite understand why there aren't more big sepex motors (and
controllers) available. (Sepex motors provide regen almost for free,
like an AC motor.) Chicken-and-egg issue, I guess. I expect we have
the Zilla because there are already a lot of big series-wound motors
being made for other markets.

So that's what I'd like - big road-capable sepex motors with
interpoles, along with Zilla-like controllers that provide regen.

How about a beefy comm design that can withstand high RPMs that packs
lots of surface area (for big amps) into a short space? Say, stacks of
disks with brushes on both sides, or a "hollow" comm with brushes on
the inside as well as the outside?

In the end, the problems that are being addressed by these requests are
not present with AC motors. So I guess we could replace them with a
wish for more affordable AC motor/controller combinations :)

I like everyone else's suggestions too!

--
Doug Weathers
Las Cruces, NM, USA
http://www.gdunge.com/

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Discussion Starter · #9 ·
Adrian,

Interpoles have windings around them, called comm
coils. These are in series with the armature, so see
full current. They have a very low resistance, on the
order of a series field resistance. So, they require
excitation power, likely to be about a percent of
motor output. That would reduce motor efficiency a
percent or so. Now, the improved commutation provided
by the interpoles is worth something. All that
sparking and heat seen by poorly commutating brushes
is taking power, right? So, eliminating that will
improve efficiency, but is hard to quantify.

Overall, I'd say interpoles are a wash when it comes
to motor efficiency.

Jeff M


--- Adrian DeLeon <[email protected]> wrote:

> How about interpoles?
>
> They would eliminate the need to advance brushes,
> make regen a bit easier,
> and keep arcing down at higher voltages/currents. A
> little extra
> length/diameter/weight would be a small price to pay
> for a more "bullet
> proof" motor. Do interpoles help improve efficiency
> at all?
>
> -Adrian
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>



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Discussion Starter · #10 ·
Id like to see an EV sized slip-ring motor. efficiency of ACIM with less
stringent freq control and the starting torque of a series wound dc motor.

but that puts us in the AC department.

Failing that
Adjustable brush rigging. In static mode it allows the user to adjust it
to match the weight of their vehicle and their driving style without
taking things apart. And allows development and later installation of
automatic adjuster.

Larger posts or dual posts , the diameter of the cables is 2 or 3 times
that of the motor post or putting dual cables on sucks.

Integral dual motor,

Real commutators instead of molded comms. Last I checked ordering a
bunch of these would bring the price into an affordable range, but the
market is dwindleing.

Get Rid of the #[email protected]% keyed shaft!
Present a small block chevy crank pattern, after market adapters to
yokes are already available.
Hollow internally splined shaft. Allows you to slide thru and bolt in
and adapter or to stack the motors in a maintainable way.

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Discussion Starter · #11 ·
Hello All,

I now have been running a interpole motor for over 30 years now. I normally
break it down every 10 years to clean it, replace bearings and may have it
re enamel. Took it to the motor shop to see if it needed any work in the
first ten years and they said they would not even touch it.

The commentator was still glass smooth, no brush marks and the brushes were
only worn down 25 percent. I was told that this GE motor commentator is a
very hard brass alloy which was MICRO MIRROR which is polish to glass smooth
surface. The brushes which are silver graphite are one grade softer then
the commentator. Not too soft or they will wear faster or not too hard of
they will wear the commentator.

Look at them 10 years later and the same story. The brushes were now at 50%
wear and the commentator was not turn at all. It was only polish to a micro
mirror surface. It was turn on a lathe while doing this micro mirror.

At 30 years, I finally replace the brushes with new pre curve silver
graphite brushes that I had in stock for over 30 years. Still have two more
sets in stock. The front of the pair brushes where down to 1/2 inch of the
brush leads and the rear brushes were a bit longer. Clean the motor, run the
motor on the bench with 12 volts, stoning the commentator to seat the
brushes, remove the brushes and rotated the motor with a external motor to
micro mirror the commentator and then put it into surface.

At 34 years, One of the field windings at the rear of the motor which was
one of the loop backs parted. Way back in the 10 year check, I notice this
part of the winding was flatten some, so it lasted that long.

Sent the motor to a GE where they originally built this motor. They
completely remanufacture the motor. In the mean time, I running a spare Warp
9 motor, should have been a Warp 11 and I plan to get a spare Warp 11 motor.
So I will have a Warp 9, maybe a adapter plate and a motor coupler in about
a year from now for anybody that needs one for a C10 pickup or any other
pickup.

Note: This motor and adapter will fit a C10 manual transmission, any other
Chevy 3 speed to 5 speed transmission with a standard Chevy bell housing.
Has the small diameter motor coupler for the later Chevy engines crank
flanges, but also will fit the large flange coupler that you can make for
this motor.

The motor also has a very heavy duty wide clam shell motor mounted with tap
holes on the side to fit any engine mounts. It also has two complete sets
of silver graphite brushes that were purchase from NetGain.

Roland




----- Original Message -----
From: "Jeff Major" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, August 30, 2007 7:41 AM
Subject: Re: [EVDL] Motor wish list


>
> Adrian,
>
> Interpoles have windings around them, called comm
> coils. These are in series with the armature, so see
> full current. They have a very low resistance, on the
> order of a series field resistance. So, they require
> excitation power, likely to be about a percent of
> motor output. That would reduce motor efficiency a
> percent or so. Now, the improved commutation provided
> by the interpoles is worth something. All that
> sparking and heat seen by poorly commutating brushes
> is taking power, right? So, eliminating that will
> improve efficiency, but is hard to quantify.
>
> Overall, I'd say interpoles are a wash when it comes
> to motor efficiency.
>
> Jeff M
>
>
> --- Adrian DeLeon <[email protected]> wrote:
>
> > How about interpoles?
> >
> > They would eliminate the need to advance brushes,
> > make regen a bit easier,
> > and keep arcing down at higher voltages/currents. A
> > little extra
> > length/diameter/weight would be a small price to pay
> > for a more "bullet
> > proof" motor. Do interpoles help improve efficiency
> > at all?
> >
> > -Adrian
> >
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> >
>
>
>
>
> ____________________________________________________________________________________
> Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user
> panel and lay it on us.
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>
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Discussion Starter · #12 ·
There were some anecdotal posts on this list that interpoled motors ran a bit cooler or with less amps.

----- Original Message ----
From: Adrian DeLeon <[email protected]>
To: [email protected]
Sent: Wednesday, August 29, 2007 10:52:44 PM
Subject: Re: [EVDL] Motor wish list

How about interpoles?

They would eliminate the need to advance brushes, make regen a bit easier,
and keep arcing down at higher voltages/currents. A little extra
length/diameter/weight would be a small price to pay for a more "bullet
proof" motor. Do interpoles help improve efficiency at all?







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Discussion Starter · #14 ·
Not that I want to waste bandwidth or anything but I have to second
and third that motion! Put my vote, preorder, show of hand,
whatever in on that one.

--- Zeke Yewdall <[email protected]> wrote:

> $5,880 on the GE website. Yikes. Is it really that much more
> expensive to make a sepex than an ADC, or Warp series motor of
> equivalent rating?
>
> And yeah.... haven't been able to find any Zilla level controller
> for it yet... :(
>
> On 8/29/07, Doug Weathers <[email protected]> wrote:
>
> > I don't quite understand why there aren't more big sepex motors
> > (and controllers) available. (Sepex motors provide regen
> > almost for free, like an AC motor.) Chicken-and-egg issue, I
> > guess. I expect we have the Zilla because there are already a
> > lot of big series-wound motors being made for other markets.

> > So that's what I'd like - big road-capable sepex motors with
> > interpoles, along with Zilla-like controllers that provide
> > regen.

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Discussion Starter · #17 ·
Doug Weathers wrote:
> Just what I was going to say :) If we had more DC motors with
> interpoles available, then perhaps we'd see more controllers that
> can do regen with DC motors.

Well, Netgain says they could offer interpoles on their WarP 11" and 13"
motors. If they know there is a demand, they might actually make it an
available option!

Interpoles, like brush timing, are one of those items that requires
"finesse" to get it just right for best results (not too much, not too
little). I think the way they should do it is to bring out the interpole
winding to separate terminals. The user could choose the phasing to suit
the direction of rotation and motor/generator operation. Plus, they
could make the interpoles a bit stronger than needed, and the user can
weaken them with an external shunt resistor to "fine tune" it for the
application.

> I don't quite understand why there aren't more big sepex motors (and
> controllers) available. Sepex motors provide regen almost for free,
> like an AC motor. Chicken-and-egg issue, I guess.

I think it is more that the usual customers of big DC motors won't pay
for it. They want cheap, so that's what they get. Maybe it is changing;
you do see more golf carts and NEVs with regen braking via sepex motors
and controllers.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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Discussion Starter · #18 ·
>I think it is more that the usual customers of big DC
>motors won't pay
>for it. They want cheap, so that's what they get.
>Maybe it is changing;

>you do see more golf carts and NEVs with regen
braking >via sepex motors
>and controllers.
Motor cost for sepex is the same, more turns of the
same amount of copper. The control will require an
H-bridge for the sepex field, but silicon cost is low
enough to offset the advantages. The field only
requires less than 20 amps max. The advantages are
regen for improved range and most importantly the
capability to prevent golf cart roll-away. If the cart
starts rolling down a hill with no accelerator input,
it sees this as a roll-away condition. You pump up
the field and limit speed to an acceptable value that
makes it go quite slow and prevent a nasty situation.
The only thing really needed with this motor/control
combination is that the software is tuned for the
motor/control. A 2,000 amp Zilla can work with a wide
range of series motors if you tune it to keep max
power under control and prevent it from burning up the
motor. A sepex system requires the control to have
much better knowledge of the motor for proper regen
and motoring operation. In other words you would not
buy an off the shelf sepex system without having the
motor parameters programmed in for proper operation.
This system is typically designed as a pair, similar
to AC drives.
Rod

--- Lee Hart <[email protected]> wrote:

> Doug Weathers wrote:
> > Just what I was going to say :) If we had more DC
> motors with
> > interpoles available, then perhaps we'd see more
> controllers that
> > can do regen with DC motors.
>
> Well, Netgain says they could offer interpoles on
> their WarP 11" and 13"
> motors. If they know there is a demand, they might
> actually make it an
> available option!
>
> Interpoles, like brush timing, are one of those
> items that requires
> "finesse" to get it just right for best results (not
> too much, not too
> little). I think the way they should do it is to
> bring out the interpole
> winding to separate terminals. The user could choose
> the phasing to suit
> the direction of rotation and motor/generator
> operation. Plus, they
> could make the interpoles a bit stronger than
> needed, and the user can
> weaken them with an external shunt resistor to "fine
> tune" it for the
> application.
>
> > I don't quite understand why there aren't more big
> sepex motors (and
> > controllers) available. Sepex motors provide
> regen almost for free,
> > like an AC motor. Chicken-and-egg issue, I guess.
>
> I think it is more that the usual customers of big
> DC motors won't pay
> for it. They want cheap, so that's what they get.
> Maybe it is changing;
> you do see more golf carts and NEVs with regen
> braking via sepex motors
> and controllers.
>
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377,
> leeahart_at_earthlink.net
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter · #20 ·
One more item for the list: water cooling.


Regarding interpoles - they may not improve efficiency much, but they'd
eliminate the "Should I advance the brushes? How much?" dilemma. White
Zombie's recent encounter with REVERSE is a good example of how interpoles
would be useful in a single reduction EV.

-Adrian

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