EV Digest 6327
Topics covered in this issue include:
1) Re: affordable BMS?
by <[EMAIL PROTECTED]>
2) Re: Lower price (and available) configurations
by Jurgen Schmidt <[EMAIL PROTECTED]>
3) RE: I Need You to Blitz GM Like Never Before
by "Doug McKee" <[EMAIL PROTECTED]>
4) Re: Lower price (and available) configurations
by "John G. Lussmyer" <[EMAIL PROTECTED]>
5) Re: AC propulsion
by "Kaido Kert" <[EMAIL PROTECTED]>
6) Re: I Need You to Blitz GM Like Never Before
by Martin K <[EMAIL PROTECTED]>
7) Controller problem
by Jennifer Herzberg <[EMAIL PROTECTED]>
8) Re: Newbie Question about AC Drives
by Jonathan Jekir <[EMAIL PROTECTED]>
9) RE: Controller problem
by Cor van de Water <[EMAIL PROTECTED]>
10) DC-DC for Link-10
by "Brian M. Sutin" <[EMAIL PROTECTED]>
11) RE: Newbie Question about AC Drives
by Don Cameron <[EMAIL PROTECTED]>
12) controller problem
by Jennifer Herzberg <[EMAIL PROTECTED]>
13) Re: BBS?
by Tehben Dean <[EMAIL PROTECTED]>
14) Re: BBS?
by James Massey <[EMAIL PROTECTED]>
15) RE: BBS?
by Don Cameron <[EMAIL PROTECTED]>
16) Re: AC propulsion
by "Mike Phillips" <[EMAIL PROTECTED]>
17) Re: DC-DC for Link-10
by Lee Hart <[EMAIL PROTECTED]>
18) Re: Conversion costs never change?
by Lee Hart <[EMAIL PROTECTED]>
19) Re: Lower price (and available) configurations
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Newbie Question about AC Drives
by Lee Hart <[EMAIL PROTECTED]>
21) Re: EEstor
by Lee Hart <[EMAIL PROTECTED]>
22) Re: Xantrex Choice Model Redux
by Lee Hart <[EMAIL PROTECTED]>
23) RE: Newbie Question about AC Drives
by "Dale Ulan" <[EMAIL PROTECTED]>
24) Re: Lower price (and available) configurations
by "Peter VanDerWal" <[EMAIL PROTECTED]>
25) Re: Lower price (and available) configurations
by Danny Miller <[EMAIL PROTECTED]>
26) Re: I Need You to Blitz GM Like Never Before
by "Steve" <[EMAIL PROTECTED]>
27) RE: controller problem
by Cor van de Water <[EMAIL PROTECTED]>
28) RE: Lower price (and available) configurations
by Cor van de Water <[EMAIL PROTECTED]>
--- Begin Message ---
>
> From: Lee Hart <[EMAIL PROTECTED]>
>
>
> My Battery Balancer is an elaborate system that uses a microcomputer to
> monitor every battery, and charge it as needed to keep them all in
> balance. It will cost you around $1000, and is open source (see it at
> http://www.geocities.com/sorefeets/balancerland/intro.htm
>
HI Lee I have sombody intrested ( as I am ) in putting together one of your
bms's , I know you needed 10 orders to pay for the boards ,,, I could get 5
controlle boards if this would help make an order ....
Steve Clunn
> --
> 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
>
>
--- End Message ---
--- Begin Message ---
You mention Uve's calculator - where can I find this?
Thanks - Jurgen Schmidt
Peter VanDerWal wrote:
Ok, I'm still curious as to why you want to do this.
At 08:07 PM 1/20/2007, you wrote:
Why on earth would you want to do this? It would be hugely expensive
even
if your ideas would work, it would also have very short range.
So, if multiple Curtis setups are "hugely" expensive, then a Z2K
setup is "astronomically" expensive?
Considering that even using 4 curtii + 4 ADCs, the total conversion cost
is probably going to run $15,000-$20,000, the Z2K setup is only 10-15%
more, so I'd say that falls under "hugely expensive" still.
Perhaps a bit less than that if you are close enough to a supllier to
pickup the parts and not have to pay shipping on over 600 lbs worth of
parts
Problems:
6V GC battteries can barely handle one controller. Using two controllers
on the same string will kill them quick.
Hmm, last I knew, lots of people use GC batteries with Curtis
controllers. Since these are 400A controllers that can't maintain
that peak for any length of time, seems like even 2 wouldn't be an
overload for GC batteries.
Yes indeed, lots of people run Curtis controllers. Some even run the more
powerful 550 amp versions; which, if you have a lead foot, will reduce the
lifespan of your pack.
400 amps will draw a freshly charge T-105 down to almost the minimum safe
voltage (1.75Vpc), after it's been discharged 20-30% it will draw it down
UNDER 1.75vpc.
You are talking about 800 AMPS worth of controllers per string. This will
kill your pack in fairly short order. Probably less than a year.
With all that weight and the relatively poor aerodynamics (poor Cd AND
large frontal area), I think you'd be lucky to get 20 miles tange with
your proposed setup.
I've been thinking about doing a full-size pickup conversion.
(something like a Ford F-250).
Which is interesting, since (as far as I can guess with the various
EV calculators) 2400lbs of batteries would seem to give considerably
more range than that.
So, what are you basing your range calculations on?
What information are you using for the calculators? I just measured my
F250, it has roughly 36 ft of frontal area. Even if the Cd is the same
as a small truck, this means that it has twice as much aero drag.
I also think your weight estimate is off by almost 1,000 lbs (I'm assuming
you were thinking of the single cab, it's even more if you are talking the
extended/crew cab)
I just ran Uve's calculator and it came up with just under 20 miles at 40
mph. This, of course, assumes steady speed driving. Add stopping and
starting 4 tons of vehicle and your range will drop dramatically.
--- End Message ---
--- Begin Message ---
I feel many are missing a small point. GM already had one and for
reasons of their own, plus the oil guys, unfettered by the fed, etc,.,
etc., decided to crush the project. The volt won't be ready for about
3-5 years at the earliest, which is, believe me, the calculated time the
American public will remain apathetically inactive and the automakers
and oil guys can ignore us with impunity.
Doug
--- End Message ---
--- Begin Message ---
At 10:24 AM 1/21/2007, Peter VanDerWal wrote:
Yes indeed, lots of people run Curtis controllers. Some even run the more
powerful 550 amp versions; which, if you have a lead foot, will reduce the
lifespan of your pack.
If you leadfoot with ANY controller and battery, it reduces the
lifespan of your pack.
400 amps will draw a freshly charge T-105 down to almost the minimum safe
voltage (1.75Vpc), after it's been discharged 20-30% it will draw it down
UNDER 1.75vpc.
You are talking about 800 AMPS worth of controllers per string. This will
kill your pack in fairly short order. Probably less than a year.
You do remember that curtii can't keep their max ratings for more
than a few seconds?
And that not everybody floors it every time they start from a light?
What information are you using for the calculators? I just measured my
F250, it has roughly 36 ft of frontal area. Even if the Cd is the same
as a small truck, this means that it has twice as much aero drag.
I also think your weight estimate is off by almost 1,000 lbs (I'm assuming
you were thinking of the single cab, it's even more if you are talking the
extended/crew cab)
I just ran Uve's calculator and it came up with just under 20 miles at 40
mph. This, of course, assumes steady speed driving. Add stopping and
starting 4 tons of vehicle and your range will drop dramatically.
So, I just did UVE's calc again.
http://www.geocities.com/CapeCanaveral/Lab/8679/evcalc.html
Non-aero small truck, 36 sq ft frontal area.
Using a 2007 (not likely!) F250 SuperCab LongBed, 5.4L V8. 5856 lb
base weight.
(I've been having trouble finding this kind of info on older models.)
Gear ratios 23.74, 13.53, 8.61, 5.33, 4.10, 2.95 (since the calc only
allows 5 speeds, I didn't use 2nd)
17" tires, Rolling resistance .015, 1000 lbs removed
For the motor, I used a L91-4003, and doubled the weight and horsepower.
For the controller, I used a curtis with 800A max.
(Basically, a pair of Curtis 400A controllers and L91 motors.)
dual 120V string of T-125's.
Hmm, this time I come out with numbers more like yours. Wonder what
I messed up last time?
Max speed: 68mph. Range @ 50mph - 17.3 miles, Range @ 10mph - 107 miles.
(hmm, of course if I used standard sales style definitions, this is a
vehicle with top speed of 68 mph, and a range of over 100 miles!)
So, lets see what needs to change to make this useable.
I tried using LRR tires (.0015 rr).
That makes a HUGE difference.
Max speed: 76mph. Range @ 50mph - 55.4 miles, Range @ 10mph - 665.6 miles.
Changing the CD to .42 made almost no difference.
So, I tried changing the battery pack to YT's (4 strings of D34's)
With crappy tires (.015 rr)
Max speed: 69mph. Range @ 50mph - 25.8 miles, Range @ 10mph - 72 miles.
With good tires (.0015 rr)
Max speed: 76mph. Range @ 50mph - 52.8 miles, Range @ 10mph - 329.8 miles.
So, I tried knocking 1000 lbs off the truck (somehow)
Only makes a slight difference (adds 3 miles to the GC, LRR 55 mile range)
In all cases the top speed was limited by voltage.
In all cases the Rolling Resistance is what controls the range.
From the calc, it would seem that weight and truck-aero improvements
aren't likely to make much difference.
If you can get LRR tires, that seems to make a HUGE difference.
And of course, finding the Rolling Resistance for different tires is
nearly impossible.
And finally, I have no idea what the acceleration would be like, as
that part of UVE's calculator was never completed.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
Anyone venture a guess at the BOM cost of their conversion kit ?
-kert
On 1/21/07, Doug McKee <[EMAIL PROTECTED]> wrote:
Hi Cor,
I think it answers the question regarding quality, but the Xb conversion
from ACP is $55,000 PLUS the cost of the Xb.
I'll have to wait for Ed McMahon's visit before I have one of those.
Doug McKee
--- End Message ---
--- Begin Message ---
This may be true, but I don't think it hurts to try. We don't have an
affordable real EV car available so it's not like we're in a position to
spite GM over their past fallacies.
--
Martin K
Doug McKee wrote:
I feel many are missing a small point. GM already had one and for
reasons of their own, plus the oil guys, unfettered by the fed, etc,.,
etc., decided to crush the project. The volt won't be ready for about
3-5 years at the earliest, which is, believe me, the calculated time the
American public will remain apathetically inactive and the automakers
and oil guys can ignore us with impunity.
Doug
--- End Message ---
--- Begin Message ---
Please advise;
I seem to have a problem with my 93 Brusa Model AC300E 144 volt DC
to150 volt AC controller. The Acgtx20 motor barely rotates
backwards. I have 2 in my Solectria Force GT, the other controller
makes either motor spin well. I pulled it apart and theres nothing
obvious. Thank you. Alan
--- End Message ---
--- Begin Message ---
Yes, Metric Mind Engineering did an AC Honda CRX. There's a
significant price premium for AC, but it's more efficient, possibly
safer (AC controllers fail off rather than on) and have regen. Metric
Mind's site has many reasons to use AC. AC drives unfortunately are
out of reach for the home converter unless you've got a rather large
pile of money sitting around. Another consideration is the voltage is
typically higher (200-400v) thus you need either a whole pile of lead
or Li-Ions.
On 20-Jan-07, at 8:52 PM, Doug McKee wrote:
I just did a Google search for AC drives and there are a bunch of
providers.
http://motion-controls.globalspec.com/Industrial-Directory/
AC_drive_truc
k
Is an AC drive a viable conversion idea for an EV?
AC Propulsion is pricey but it looks like the technology is in use in
multiple arenas so maybe it's not as expensive elsewhere.
Thanks in advance for your patience.
Doug McKee
--- End Message ---
--- Begin Message ---
Hi Alan/Jennifer,
Can the Brusa be programmed to limit its operation in backwards
direction? My controller has many parameters to configure it
and one of them says that I cannot make the controller go
faster than 20 MPH backwards.
The controller converts this to a max RPM for the motor, my
motor goes about 125 RPM for every MPH, at the configured
max RPM of 9000 the forward speed is 72 MPH.
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Jennifer Herzberg
Sent: Sunday, January 21, 2007 11:17 AM
To: [email protected]
Subject: Controller problem
Please advise;
I seem to have a problem with my 93 Brusa Model AC300E 144 volt DC
to150 volt AC controller. The Acgtx20 motor barely rotates
backwards. I have 2 in my Solectria Force GT, the other controller
makes either motor spin well. I pulled it apart and theres nothing
obvious. Thank you. Alan
--- End Message ---
--- Begin Message ---
What happens if the pack sags below 85V?
> Go to www.astrodyne.com or call 1-800-823-8082. Order one MSCC-5003 for
> $80. Yes, it's expensive; but I guarantee it will do the whole job
> right. This is a potted block with screw terminals, easy chassis mount,
> 85-265vac input, 15v 3w output, and 3000vac isolation. It actually works
> on DC, for any pack from 96v to 350v DC -- I've tested it myself.
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--
Brian M. Sutin, Ph.D. Space System Engineering and Optical Design
Skewray Research/316 W Green St/Claremont CA 91711 USA/(909) 621-3122
--- End Message ---
--- Begin Message ---
Doug, AC is not only viable, but many are doing it! Check out what I did
with a Siemens unit from metric mind. Also check out the other AC EVs on
EVAlbum.com, try Search->motor type->3 phase AC
Don
Don Cameron, Victoria, BC, Canada
---------------------------------------------------
See the New Beetle EV project www.cameronsoftware.com/ev
Check the EVDL Archives: http://autos.groups.yahoo.com/group/ev-list-archive
Check out the EV FAQ: www.evparts.com/faq
Check out the EV Photo Album: www.evalbum.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Doug McKee
Sent: January 20, 2007 5:53 PM
To: [email protected]
Subject: Newbie Question about AC Drives
I just did a Google search for AC drives and there are a bunch of providers.
http://motion-controls.globalspec.com/Industrial-Directory/AC_drive_truc
k
Is an AC drive a viable conversion idea for an EV?
AC Propulsion is pricey but it looks like the technology is in use in
multiple arenas so maybe it's not as expensive elsewhere.
Thanks in advance for your patience.
Doug McKee
--- End Message ---
--- Begin Message ---
to clarify, Cor the moter is creeping the opposite direction that the
switch is set for , forward or reverse thanks Alan
--- End Message ---
--- Begin Message ---
I don't mean to start this discussion again but I wanted to answer : )
I would prefer a web forum for several reasons. I have not been
reading this list for the last several days (as you can see I am
replying to a topic that has by now pretty much dried up) and I now
have about 500 emails to scan through!
It is hard to follow one discussion if you don't read the list every
single day, and then when you do return you have gazillions of
messages to sort through.
I admit there are some advantages to the current setup in that
nothing is hidden off in a corner, all ideas are out in one big box
so to speak but I think that a forums advantages outweigh a lists.
But then again I am just a kid (19) ; )
Someone asked about how new listees have found this list I can't
remember but it was not very easy as I recall.
Tehben
--- End Message ---
--- Begin Message ---
At 02:26 PM 21/01/07 -0900, Tehben wrote:
I don't mean to start this discussion again but I wanted to answer : )
I would prefer a web forum for several reasons. <snip> I think that a
forums advantages outweigh a lists.
But then again I am just a kid (19) ; )
Then you need an email program that makes your email work in a way that
suits you. Don't try and make 1000 other people change to suit you. Don't
ask me what Email program - I'm happy with Eudora Light. I'm sure others
can chime in and say what will do this for you.
Someone asked about how new listees have found this list I can't
remember but it was not very easy as I recall.
I seem to recall doing a search for EVs and getting a bunch of archive hits
referring to the EVDL, so I then searched for EVDL and found it. Wasn't
hard, but that was about 5 years ago.
Just my 0.02
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
Tehben,
To review the EVDL by thread, look at:
http://autos.groups.yahoo.com/group/ev-list-archive
Don Cameron, Victoria, BC, Canada
---------------------------------------------------
See the New Beetle EV project www.cameronsoftware.com/ev
Check the EVDL Archives: http://autos.groups.yahoo.com/group/ev-list-archive
Check out the EV FAQ: www.evparts.com/faq
Check out the EV Photo Album: www.evalbum.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tehben Dean
Sent: January 21, 2007 3:27 PM
To: [email protected]
Subject: Re: BBS?
I don't mean to start this discussion again but I wanted to answer : ) I
would prefer a web forum for several reasons. I have not been reading this
list for the last several days (as you can see I am replying to a topic that
has by now pretty much dried up) and I now have about 500 emails to scan
through!
It is hard to follow one discussion if you don't read the list every single
day, and then when you do return you have gazillions of messages to sort
through.
I admit there are some advantages to the current setup in that nothing is
hidden off in a corner, all ideas are out in one big box so to speak but I
think that a forums advantages outweigh a lists.
But then again I am just a kid (19) ; )
Someone asked about how new listees have found this list I can't remember
but it was not very easy as I recall.
--- End Message ---
--- Begin Message ---
It was $25k.
Mike
--- In [EMAIL PROTECTED], "Kaido Kert" <[EMAIL PROTECTED]> wrote:
>
> Anyone venture a guess at the BOM cost of their conversion kit ?
>
> -kert
>
> On 1/21/07, Doug McKee <[EMAIL PROTECTED]> wrote:
> > Hi Cor,
> > I think it answers the question regarding quality, but the Xb
conversion
> > from ACP is $55,000 PLUS the cost of the Xb.
> > I'll have to wait for Ed McMahon's visit before I have one of those.
> > Doug McKee
> >
> >
> >
>
--- End Message ---
--- Begin Message ---
From: "Brian M. Sutin"
>What happens if the pack sags below 85V?
The www.astrodyne.com MSCC-5003 is a 5w converter. When the input voltage goes
below 85v, its power output is gradually reduced. The E-meter only uses 2w, so
you can go well below 85v before the MSCC-5003's output sags below 12v. The one
I tested worked down to 60v DC.
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
David Roden wrote:
It's unclear to me why a vehicle purpose-built as an EV should lose
1000 lb simply by virtue of being an EV.
A purpose-built EV *should* lose 1000 lbs over a comparable ICE;
otherwise, you're wasting your time! Sure, we could build airplanes out
of stamped steel like we do cars -- but if we did, they'd be heavier,
perform worse, and be less efficient.
The designers of a purpose-built EV know that for it to be successful,
it has to lightweight. They have a chance to make a paradigm shift, and
re-think all sorts of details.
You don't need a transmission, but what other source of excess
weight do you lose?
Obviously, the electric motor is much lighter than the ICE, and you get
rid of all sorts of associated parts (radiator, gas tank, exhaust
system, etc.) Less insulation and sound deadening, because EVs are
intrinsically quieter. Smaller A/C systems because there's less heat.
--
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
--- End Message ---
--- Begin Message ---
John Lussmyer wrote:
>> I've been thinking about doing a full-size pickup conversion.
>> (something like a Ford F-250).
Peter VanDerWal wrote:
Why on earth would you want to do this? It would be hugely expensive
even if your ideas would work, it would also have very short range.
Problems:
6V GC batteries can barely handle one controller. Using two
controllers on the same string will kill them quick.
With all that weight and the relatively poor aerodynamics (poor Cd AND
large frontal area), I think you'd be lucky to get 20 miles range with
your proposed setup.
It might not be as bad as you think, Peter.
He talked about a 240v pack of 6v GC batteries. If the truck uses 500
wh/mile (double that of a car), that's about 2 amphours/mile or 60 miles
range at modest speeds. If it takes 30kw to push it at 60 mph (again,
double that of a car), that's only a 125 amp draw from the batteries,
which would give you a 30 mile range at 60 mph. Not bad at all.
It's important to note that there are some economies of scale. Doubling
the weight of a vehicle does not quite double its horsepower
requirements, because wind resistance is not proportional to weight. And
though the F-250 is big, it probably does not have twice the wind
resistance of (say) a ranger pickup.
So, he's got twice the pack of a Ranger Pickup EV conversion, but hasn't
doubled his power requirement. So it may actually perform better, not worse.
I could use multiple smaller motors, and multiple smaller controllers.
Say, Curtis 1221C + ADC L91-4003, $975 + $840. Thats 400A (max, I
know, derate for continuous) at 120V.
For the price of the Dual Motor Z2K setup, I could get 5 Curtis setups +
extra.
I suspect that 5 motors/controllers would be too much. The batteries
can't deliver over 500 amps if you expect them to last. So, a pair of
Curtis 1231C controllers and ADC 9" motors might be all the batteries
could easily handle.
What would 2 of the Curtis setups do in a vehicle like this?
I suspect you'd have a "lead sled" type of EV that accellerates slow and
takes a while to reach 60 mph -- but this may be fine for what you want
to do with it. As above, I think your range would be in the 30-60 miles,
depending on speed.
--
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
--- End Message ---
--- Begin Message ---
Doug McKee wrote:
I just did a Google search for AC drives and there are a bunch of
providers. Is an AC drive a viable conversion idea for an EV?
These inexpensive industrial AC drives are not traction drives (intended
to move a vehicle). A "10 hp" AC drive can only deliver that at full
speed. At other speeds, the horsepower falls proportionately to speed
(half speed is half hp; 1/10th speed is 1/10th hp etc.). Basically, they
are constant torque devices, and can not supply higher torques at lower
speeds for anything more than a couple seconds.
A traction motor drive has to deliver high horsepower over a range of
speeds. A "10 hp" DC traction drive can deliver it over a broad range of
speeds. They also have to deliver very high starting torques for a
considerable length of time, for example 3-4 times rated torque for
minutes at a time.
An industrial AC drive big enough to use as a traction motor drive will
probably need to be rated at 50+hp to match a 10 hp DC traction motor drive.
There are also some environmental and packaging issues; industrial
drives are often built only for indoor use, where they stay clean, dry,
and cool.
--
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
--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
For a DC motor controller... it looks surprisingly like a Zilla,
with 3 differences:
1. Internal induction to avoid the motor ever seeing 3500V spikes,
2. Voltage range will require a new extra-extra high voltage
version to withstand the 0 to 3500V switching
3. Luckily the current can be a lot lower, although it will be
a major challenge to get the same 600kW out of a Zilla
I don't think a simple buck converter makes sense for such a large
voltage reduction. Buck converters do not lend themselves to large
input-output voltage ratios.
1. The inductor stores energy. With a large input voltage and large
output current, it becomes impractically large.
2. The transistors in a buck converter have to handle the peak input
voltage and the peak output current. For (say) 3500v input and
600a output, that's 2.1 *megawatts* worth of transistors! Enough
to build 10 Zillas!
There are better topologies. For one, you can tap the inductor so it
serves as an autotransformer. If the output is to range from say 0-350v
(10% of the input), a 10% tap on the inductor means the transistors
still have to switch full voltage, but at only 10% of the output current.
--
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
--- End Message ---
--- Begin Message ---
MARK DUTKO wrote:
The meter will only measure 500A but not go higher, if you pull say 600
it will only read and compute against the max of 500A.
Minor point; the actual maximum is 511 amps.
It is just a software change to make it go to 1022 amps.
--
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
--- End Message ---
--- Begin Message ---
Is an AC drive a viable conversion idea for an EV?
AC Propulsion is pricey but it looks like the technology is in use in
multiple arenas so maybe it's not as expensive elsewhere.
I'm mostly an EV newbie, but I've been designing industrial and
automotive electronics for about 15 years now, so most of this
is from that viewpoint....
It is slowly getting that way. An AC induction motor is a lot easier
to manufacture than a brushed motor. Most industrial and home motors
above about 1/8 HP are AC induction motors. Many motors below that
are brushless or brushed DC motors. But the costs are only low
once it's tooled up. Mechanically, an EV AC motor really needs to be
sized at about the 10HP or 15HP level. So really, you should be
able to get an idea of what EV motors COULD be made for - just price
out a 10 to 15HP (maybe as high as 20HP) 3-phase, 208V induction
motor. Add a speed sensor (tach) to it, and you're there.
AC Propulsion makes very nice but expensive
high performance systems. I've been looking at AC vs DC from an
electronics components standpoint... mostly because I got a pair of
brushless DC Solectria motors, one missing the power portion of its
controller, and I needed to fix it. Which means I needed to find
IGBT's or MOSFETS to replace the obsolete ones used in there.
Anyways, the current 'state of the art' in motor DSP and other control
electronics at around $50 or $60, plus a bunch of software to
write. In mass manufacture, take that and drop it down to probably $30.
That is for a 'zero kW' motor drive. The power stages cost money.
Here's what I found, this is to build 3 or 4 drives, the price is for
IGBT followed by Capacitors, wiring, bus bars, current sensors, etc.
1-2.5 kW $22.00 $6.00
18 kW $138.00 $65.00
36 kW $219.00 $85.00
85 kW $282.00 $100.00
150 kW $1464.00 $250.00
As you can see, there are a couple of significant jumps. The small VFD
market (<2.5 kW - the $100 or so VFD's) are obviously very cost effective.
They need to be. Fridges and home air conditioning systems are the targets
of many of these systems, but so are a lot of small industrial applications-
lathes, conveyer belts, pumps.
Around 20kW you find different industrial applications. Large pumps, air
compressors, big milling machines. There is a jump up to be in this power
level - around 75 amps instead of 20 or 30 amps. Above this, things pretty
much scale linearly out to about the 300 amp level. Jumping much above
this power level significantly reduces the choices in semiconductor vendors,
and the costs go up a lot. Large pumps (oil pumps, large compressors)
can be in this power level.
Many industrial applications over 50kW are not particularly cost-
sensitive (after all, the motors are rather significant at this
power level, considering that they are usually rated for continuous
use at these power levels. Often the voltage rail goes up to 900V or
so, which is not particularly easy to battery-up for in an EV. The
high-current (600A, 600V) parts become very expensive - and these higher
power levels aren't as commonplace as the lower-power ones.
It is also a lot harder to design a VFD to not blow up at these
power levels. I think that any power level under 5kW is pretty trivial,
power levels under 50kW are actually relatively easy to deal
with, and above that, things get hairy very quickly. I just built
up the power stage for my Solectria (30kW, 144V IGBT power stage), and
it 'just worked'. I just put in the snubbing capacitors recommended
by the IGBT vendor, set the current limiter up properly, and powered it
up. I had never built up anything that large and I was rather surprised.
A road test will tell once I get this motor into a vehicle. I might
be surprised and find that it runs at 300 amps without any trouble. Note
that the 300 amp limit in this case is determined by demagnetizing the
permanent magnets - the same limits you have on brushed PM motors.
In theory you could take an industrial VFD and run a vehicle with it.
It should work fine if you just hook the DC bus up to the battery pack
with the correct voltage.
It depends where the logic supply comes from, too. If the logic supply
comes from the DC bus, then you're ok. If it has a separate transformer,
you will need to provide DC to DC converter(s) for those supply rails.
They aren't really designed for EV operation, though, and the
weight may be a bit too much. Also, most industrial processes are constant
speed, which is difficult to drive with, unless you can turn off the
speed integral term. Some of the Metric Mind inverters look nice.
If I didn't have my BLDC's, I would probably get one of those inverters
and motors.
Now that I have a motor and a charger, I need to buy a glider and
batteries....
-Dale
--- End Message ---
--- Begin Message ---
> If you leadfoot with ANY controller and battery, it reduces the
> lifespan of your pack.
Yes, but a 400 amp controller and 6V GC batteries are a good match. You
can't draw enough current for long enough to really damage the pack.
>
>>400 amps will draw a freshly charge T-105 down to almost the minimum safe
>>voltage (1.75Vpc), after it's been discharged 20-30% it will draw it down
>>UNDER 1.75vpc.
>>You are talking about 800 AMPS worth of controllers per string. This
>> will
>>kill your pack in fairly short order. Probably less than a year.
>
> You do remember that curtii can't keep their max ratings for more
> than a few seconds?
> And that not everybody floors it every time they start from a light?
Yes, and a 6V GC battery can only source 400 amps for a few seconds, like
I said a good match.
Even if your dual controllers can only do 75% continuous, that's still 50%
more than the batteries can handle.
A single 550 amps controller is hard on 6V batteries, dual 400 amp is WORSE.
> So, lets see what needs to change to make this useable.
>
> I tried using LRR tires (.0015 rr).
> That makes a HUGE difference.
> Max speed: 76mph. Range @ 50mph - 55.4 miles, Range @ 10mph - 665.6
> miles.
Except, as far as I've been able to determine, NOBODY makes a LRR Light
Truck tire.
>
> Changing the CD to .42 made almost no difference.
>
> So, I tried changing the battery pack to YT's (4 strings of D34's)
> With crappy tires (.015 rr)
> Max speed: 69mph. Range @ 50mph - 25.8 miles, Range @ 10mph - 72 miles.
Now, at least, you have batteries that can handle the current. Of course
your costs just went up even more. Don't forget to add the cost of
battery regulators.
>
> With good tires (.0015 rr)
But non-existent tires.
Even if you could find 17 LRR tires, they have to be rated to handle the
weight (we're talking about 1 ton per tire)
Personally, I think the standard 0.15 rr figure is optimistic for LT tires
carrying this much weight.
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
But they do make truck tires with widely varying inflation
recommendations. There are bound to be some much better than others.
Unfortunately, nobody's advertising the RR one way or another.
You know what? I really do think the government should require tire
mfgs to include rolling resistance just like a car mfg is required to
state mfg. Anybody see a problem with this concept?
Danny
Peter VanDerWal wrote:
So, lets see what needs to change to make this useable.
I tried using LRR tires (.0015 rr).
That makes a HUGE difference.
Max speed: 76mph. Range @ 50mph - 55.4 miles, Range @ 10mph - 665.6
miles.
Except, as far as I've been able to determine, NOBODY makes a LRR Light
Truck tire.
--- End Message ---
--- Begin Message ---
> Responding to a recent article at:
> http://www.bloomberg.com/apps/news?pid=20601039&sid=a70odMy4PSuY&refer=home
Doron Levin wrote:
"Though the EV1 was a resounding flop, many critics of GM accused the company of
deliberately failing to market it properly, presumably to prove to regulators
that the
public really didn't want zero-emission technology. Last year's highly acclaimed
documentary film, ''Who Killed the Electric Car?,'' rubbed more salt in the
wound by
portraying GM, other automakers and oil companies as villains."
-----
The EV1 did flop because GM did fail to market it properly. That 'the EV1 was a
resounding
flop' fits a corporation view, that big companies at times make big mistakes.
There are
generalizations about their motivation. GM may have wanted to prove a point to
Federal
regulators. GM may have also thought a decent Electric car could not be built.
What is
plain is they built way too few to actually sell them, and needed to recoup
some of the
program costs so chose to lease them. GM created a business case, and built a
decent
electric car. They then shut down the lease program and crushed the cars. In
last year's
highly acclaimed documentary film, ''Who Killed the Electric Car?,'' GM is
correctly
listed as one of several villians.
Steve Love -- [EMAIL PROTECTED]
----- Original Message -----
From: "Martin K" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, January 21, 2007 5:27 PM
Subject: Re: I Need You to Blitz GM Like Never Before
> This may be true, but I don't think it hurts to try. We don't have an
> affordable real EV car available so it's not like we're in a position to
> spite GM over their past fallacies.
> --
> Martin K
>
> Doug McKee wrote:
> > I feel many are missing a small point. GM already had one and for
> > reasons of their own, plus the oil guys, unfettered by the fed, etc,.,
> > etc., decided to crush the project. The volt won't be ready for about
> > 3-5 years at the earliest, which is, believe me, the calculated time the
> > American public will remain apathetically inactive and the automakers
> > and oil guys can ignore us with impunity.
> >
> > Doug
> >
> >
>
--- End Message ---
--- Begin Message ---
Hi Alan,
Did you check (with oscilloscope or RMS voltmeter) that you
have the same motor voltage on all 3 outputs?
It almost sounds as if one of the outputs does not or barely
give a voltage/current out, so there is no rotating 3-phase
field.
Can also be a driver to the output transistors that is broken
or does not get power supply (each driver needs its own,
isolated power supply).
One other reason that almost no movement is generated
in my controller and some other AC controllers is when the
RPM / position sensor is not connected or does not give
a signal.
Since you swapped motors and both worked on the other
controller, it must be something inside the controller.
I had the problem that I broke the wire that gave 5V supply
to the RPM sensor at the motor axle end. This wire was in
my controller - if your controller has the same feature,
then it may be protecting itself by only creeping the motor,
trying to see input from its sensor.
Hope this helps,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Jennifer Herzberg
Sent: Sunday, January 21, 2007 4:31 PM
To: [email protected]
Subject: controller problem
to clarify, Cor the moter is creeping the opposite direction that the
switch is set for , forward or reverse thanks Alan
--- End Message ---
--- Begin Message ---
The biggest drawback that I see is that although weight does hardly
impact the Wh/mi when at speed, it *will* impact the amount of
energy required to get up to speed.
I have calculated that to "take off" from zero to freeway speed,
I lose approximately 1 mile of range, because it is converted
into kinetic energy (moving mass).
Doubling that mass simply doubles the energy, so to get up to
freeway speed could cost you up to 2 miles of range.
If you have bad traffic, with lots of getting to high speed and
then braking hard repeatedly, your range could be very low,
especially with DC where regeneration is not easy.
Regards,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Lee Hart
Sent: Sunday, January 21, 2007 12:54 PM
To: [email protected]
Subject: Re: Lower price (and available) configurations
John Lussmyer wrote:
>> I've been thinking about doing a full-size pickup conversion.
>> (something like a Ford F-250).
Peter VanDerWal wrote:
> Why on earth would you want to do this? It would be hugely expensive
> even if your ideas would work, it would also have very short range.
>
> Problems:
> 6V GC batteries can barely handle one controller. Using two
> controllers on the same string will kill them quick.
>
> With all that weight and the relatively poor aerodynamics (poor Cd AND
> large frontal area), I think you'd be lucky to get 20 miles range with
> your proposed setup.
It might not be as bad as you think, Peter.
He talked about a 240v pack of 6v GC batteries. If the truck uses 500
wh/mile (double that of a car), that's about 2 amphours/mile or 60 miles
range at modest speeds. If it takes 30kw to push it at 60 mph (again,
double that of a car), that's only a 125 amp draw from the batteries,
which would give you a 30 mile range at 60 mph. Not bad at all.
It's important to note that there are some economies of scale. Doubling
the weight of a vehicle does not quite double its horsepower
requirements, because wind resistance is not proportional to weight. And
though the F-250 is big, it probably does not have twice the wind
resistance of (say) a ranger pickup.
So, he's got twice the pack of a Ranger Pickup EV conversion, but hasn't
doubled his power requirement. So it may actually perform better, not worse.
>> I could use multiple smaller motors, and multiple smaller controllers.
>> Say, Curtis 1221C + ADC L91-4003, $975 + $840. Thats 400A (max, I
>> know, derate for continuous) at 120V.
>> For the price of the Dual Motor Z2K setup, I could get 5 Curtis setups +
>> extra.
I suspect that 5 motors/controllers would be too much. The batteries
can't deliver over 500 amps if you expect them to last. So, a pair of
Curtis 1231C controllers and ADC 9" motors might be all the batteries
could easily handle.
>> What would 2 of the Curtis setups do in a vehicle like this?
I suspect you'd have a "lead sled" type of EV that accellerates slow and
takes a while to reach 60 mph -- but this may be fine for what you want
to do with it. As above, I think your range would be in the 30-60 miles,
depending on speed.
--
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
--- End Message ---
