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Today's Topics:
1. EV-1C controller - Was: Design Variables - Controller -
Voltage / Current - Battery - Voltage / Capacity (Steven **)
2. Re: Glitter in the Coolant, not? (Lee Hart)
3. Re: How about a CVT and constant speed motor? (Morgan LaMoore)
4. E-boat, most efficient hull (Mark Hanson)
5. EV "Muscle Cars" (was: Nedra AC records, I want it all)
(Bill Dube)
6. Re: E-boat, most efficient hull (SteveS)
7. Re: High voltage systems (Lee Hart)
8. Re: 100+ new Li Battery companies (Jeff Major)
9. Re: Design Variables - Controller - Voltage / Current -
Battery - Voltage / Capacity (Jeff Major)
----------------------------------------------------------------------
Message: 1
Date: Thu, 31 Jan 2008 12:27:39 -0600
From: "Steven **" <[EMAIL PROTECTED]>
Subject: [EVDL] EV-1C controller - Was: Design Variables - Controller
- Voltage / Current - Battery - Voltage / Capacity
To: "Electric Vehicle Discussion List" <ev@lists.sjsu.edu>
Message-ID:
<[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1
I Googled a bit and didn't find much. What is this EV-1C controller?
What are the specs? Are they available for purchase somewhere?
-Steven
On Jan 30, 2008 7:17 PM, Steve Powers <[EMAIL PROTECTED]> wrote:
> I have been doing a lot of experiments with my car
> over the past year. Here is the progression (93
> Festiva with 9" ADC):
>
>
> 8. 84 V / 450 A EV-1C - no bypass
> 7 brand new Optimas (carrying 9, 2 not hooked up)
> Top speed 42 MPH in 2nd
> Accelerates better than ICE car. No issues.
>
------------------------------
Message: 2
Date: Thu, 31 Jan 2008 12:33:16 -0600
From: Lee Hart <[EMAIL PROTECTED]>
Subject: Re: [EVDL] Glitter in the Coolant, not?
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
[EMAIL PROTECTED] wrote:
> OK so I've now put about 1 teaspoon of the glitter and I does seem to
> decrease its obviousness over a short period of time so I'm not convinced I
> should
> keep adding more.
Sounds like it's getting trapped somewhere. It might be worth finding
out where, in case it's plugging up a line somewhere.
--
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
------------------------------
Message: 3
Date: Thu, 31 Jan 2008 12:28:15 -0600
From: "Morgan LaMoore" <[EMAIL PROTECTED]>
Subject: Re: [EVDL] How about a CVT and constant speed motor?
To: "Electric Vehicle Discussion List" <ev@lists.sjsu.edu>
Message-ID:
<[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1
On Thu, Jan 31, 2008 at 11:48 AM, fsabolich <[EMAIL PROTECTED]> wrote:
> As for high speed, you don't need high voltage. You can simply weaken the
> field.
But high speed does require a motor that's designed to handle high
frequencies. Normal industrial AC motors will have excessively high
core losses at higher frequencies (leading to excessive heating and
reduced safe power levels); you probably can't take them over 120Hz.
-Morgan LaMoore
------------------------------
Message: 4
Date: Thu, 31 Jan 2008 13:54:49 -0500
From: Mark Hanson <[EMAIL PROTECTED]>
Subject: [EVDL] E-boat, most efficient hull
To: <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset="iso-8859-1"
Hi,
I was thinking of selling my gas H2o ski boat and converting a catamaran (with
roof solar panels) that I think has the most efficient hull. (I couldn't find
Jerry Dycus email address). What is the most efficient hull to convert?
I also heard that a shrouded/ducted prop or prop winglet tip-fins make the
electric motor 15% more efficient (15% less kWh used per mile traveled). Is
that true? is there a good source to buy from?
Thanks,
Mark
_________________________________________________________________
Connect and share in new ways with Windows Live.
http://www.windowslive.com/share.html?ocid=TXT_TAGHM_Wave2_sharelife_012008
------------------------------
Message: 5
Date: Thu, 31 Jan 2008 11:12:11 -0700
From: Bill Dube <[EMAIL PROTECTED]>
Subject: [EVDL] EV "Muscle Cars" (was: Nedra AC records, I want it
all)
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset="us-ascii"; format=flowed
The very top NEDRA records are what I think most folks were referring to.
(Indeed, you can pick a class and division that has NO previous
record and then turn in a pair of timeslips with _any_ ET on them to
set an official NEDRA record.)
Because of the remarkable advances in battery technology, we are
going to see an explosion of electric records and EV "Muscle" cars in
the next year or two. Now that the batteries are here, the rest of
the drive package is advancing to catch up. This is pretty much the
same thing that happened when lead-acid AGMs became available. The
Zilla was created to harness the new HP that was coming out of the
new batteries. Likewise, the next generation of "monster" drive
packages will come on the market to meet the demand created by the
present generation of "monster" batteries.
Off-the-shelf "Muscle Car" AC drive packages are starting to emerge
(MetricMind is ratcheting up the kW of the biggest drive, seemingly
monthly.) Give it a few years and there will be off-the-shelf _BIG_
HP AC drives available as a stock item.
As I have said before, "Give it two, maybe three years, and electrics
will be _the_ fastest way to get down the track."
Bill Dube'
------------------------------
Message: 6
Date: Thu, 31 Jan 2008 14:17:12 -0500
From: SteveS <[EMAIL PROTECTED]>
Subject: Re: [EVDL] E-boat, most efficient hull
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Mark Hanson wrote:
> Hi,
>
> I was thinking of selling my gas H2o ski boat and converting a catamaran
> (with roof solar panels) that I think has the most efficient hull. (I
> couldn't find Jerry Dycus email address). What is the most efficient hull to
> convert?
>
>
Like this?:
http://www.tamarackelectricboats.com/
- SteveS
------------------------------
Message: 7
Date: Thu, 31 Jan 2008 13:42:44 -0600
From: Lee Hart <[EMAIL PROTECTED]>
Subject: Re: [EVDL] High voltage systems
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Jeff Shanab wrote:
> It doesn't automatically cost 3 times as much.
> The power silicone is the single largest cost
"Silicon", not silicone. Silicone is what's used in bathtub caulk and
breast implants. "Power silicone" suggests some strange mental pictures. :-)
> but instead of 1000Amps worth in parallel, you are gonna have them
> split out into phases for the same overall power rating.
It's complex to compare DC and AC controllers, because their operation
is so different, and so many design variations.
Consider a DC controller like the Curtis 1221, rated at 120 volts and
400 amps. It can deliver 120v x 400a = 48 KW to a motor. It has 35
MOSFETs rated at 21 amps each. You might think this means it could
handle 35 x 21a = 735a -- but without a safety factor, it would die
within minutes at 735a. A 400a rating means each transistor is asked to
handle 400a/35 = 11.4a for a reasonable life expectancy.
Suppose you used the same parts to make a 3-phase AC controller. We need
six sets of transistors, so let's round up the number of MOSFETs to 36,
which is 6 per switch. With the same derating as the Curtis, each MOSFET
can carry 11.4a. 6 x 11.4a = 68.4a per phase. That is the RMS current in
each switch. We use RMS (and not peak or average) because in AC
circuits, RMS values are the ones with the same heating effect as DC.
Now, what motor phase current corresponds to 68.4a per switch? This is a
hard question, because it depends heavily on the waveform, and when we
are synthesizing a sinewave, the waveform for each switch is strange.
But as a first approximation, let's just say the phase current is 1.4
times the switch current. I say that because each switch is on for half
the time (one half-cycle of the AC we are generating), and each switch
can have 2x the power dissipation for 1/2 the time, and for resistive
devices like MOSFETs, twice the power for half the time means it's
carying 1.4 times the current during its on-times. So, our motor's phase
current is 1.4 x 68.4a = 96 amps.
In a 3-phase motor, the total power is 2 x Vrms(phase) x Irms(phase).
With a 120vdc pack, our peak AC voltage is 120v; this makes the RMS AC
voltage we can generate 120vpeak / 1.4 = 86 volts RMS. Our RMS current
is 96 amps, so motor power is 2 x 86v x 96a = 16.5 KW.
Now, we started with parts that could build a 48 KW DC controller. So
the AC controller delivers 16.5kw / 48kw = 1/3rd of the power.
If you accept that the cost of a controller is largely set by the power
silicon, then the silicon for an AC controller costs about 3 times more
than an equivalent DC controller.
--
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
------------------------------
Message: 8
Date: Thu, 31 Jan 2008 11:43:58 -0800 (PST)
From: Jeff Major <[EMAIL PROTECTED]>
Subject: Re: [EVDL] 100+ new Li Battery companies
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=iso-8859-1
--- Idgit <[EMAIL PROTECTED]> wrote:
>
http://www.metricmind.com/misc/supercaps_in_force.pdf
> in showing
> efficiency gains, or losses from caps.
>
> Just for ballpark figures, how many WH's is a
> typical supercap bank for say
> a 2200# commuter EV, DC system, without regen
> braking, how much do they
> cost, and how costly to integrate with a Lithium
> pack? I know there are
> many variables here, but just ballpark info.
>
> Many thanks.
> Idgit
Hi Idgit,
Well, there is no "typical supercap bank". The
article explains a lot. They had a 82 Watt-hour bank.
For kicks, use 2 cents per Joule (Watt-second). Then
82 Whr = 295,200 Joules. Or $5904. That is not
including packaging or control electronics. Also, the
article said 82 Whr was too small for the vehicle size
and 50 mph.
I have done work with ultracapacitors in hybrid
vehicles. I like them. Great for 5 to 10 second
power requirements. I see them as the ticket for
vehicles doing numerous stops and starts using
regeneration. Otherwise, I don't think think they
will offer a performance/cost payback. Whether in a
BEV or HEV.
Regards,
Jeff M
____________________________________________________________________________________
Never miss a thing. Make Yahoo your home page.
http://www.yahoo.com/r/hs
------------------------------
Message: 9
Date: Thu, 31 Jan 2008 11:47:41 -0800 (PST)
From: Jeff Major <[EMAIL PROTECTED]>
Subject: Re: [EVDL] Design Variables - Controller - Voltage / Current
- Battery - Voltage / Capacity
To: Electric Vehicle Discussion List <ev@lists.sjsu.edu>
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=iso-8859-1
Hi Steve,
Very interesting. I did some similar testing a few
years back and also found 21 nickel D cells worked
well in parallel with 2 Optimas. I was using NiCads.
And just on a test stand, never a full blown set in a
vehicle.
We had a weight and cost situation which dictated the
combination of lead and nickel. Looking at the
comments near the end of your post begs the question,
why bother with the lead?
Regards,
Jeff M
--- Steve Powers <[EMAIL PROTECTED]> wrote:
> I have been doing a lot of experiments with my car
> over the past year. Here is the progression (93
> Festiva with 9" ADC):
<snip>
> I'll
> probably
> end up taking the 2nd string out and replacing it
> with
> NiMH eventually - read on for why I think that.
>
> I have also tried parallel strings using the AGMs in
> combination with NIMH (21 D cells per 2 Group 24
> AGMs). Lithium packs (various designs to optimize
> the
> voltage difference), etc. etc. etc.
>
> What I have learned is that lead acid batteries (in
> my
> opinion) are junk. It doesn't matter if they are
> Trojan flooded lead or premium AGM. By the time you
> drain them at any kind of EV drain rate you are
> going
> no where fast (or in some cases with a 320 A
> controller slow). Cycle life - even worse.
>
> NiMH and NiCD. I like them, but the BMS is a
> challenge. Charging is a challenge. Hooking them
> together really isn't as bad as people think.
>
<snip>
>
> What do I think is best? I'd still put my money on
> a
> single string of small AGMs (120 - 144 V) with NiMH
> modules in parallel scattered through the system. I
> have a way to control the charging and the
> discharging. It's very simple. Use the 21 cells
> across a pair of AGM's. Charge the AGMs. Max
> charge
> voltage for the AGMs will be 14.8 V. Resting
> voltage
> after charge for the AGMs will be 13.2 V. Simply
> use
> a diode to only allow the NiMH to charge off the PBA
> and charger, never allow the NiMH charge to back
> flow
> into the AGMs. When its done, you will have 21 NIMH
> cells at about 29 - 29.5 V and the AGMs resting
> nicely
> at 13.2 V each. Then, use contactors (1 per pair of
> AGMs) and a simple switch with time delay. You
> press
> the accelerator, the controller fires up, then the
> NiMH goes in parallel with the AGMs. As soon as you
> let off the accelerator, they seperate. Put in a
> few
> fuses for safety and you have a workable system. It
> isn't a perfect charge algorithm, but it works. If
> a
> cell goes bad, the AGM will attempt to dump charge
> the
> balance of the cells and they will drop out because
> the fuse will blow. Simple as that. The only bad
> thing is that you have to keep the charge rate kind
> of
> slow. This is a 10 - 12 hour charge for the whole
> system. And, you can use as many strings of NiMH as
> you want and long as they can only charge off the
> PBA.
> Simple use of diodes and fuses prevents any unsafe
> dump charge and runaway. Ok, if you want to have a
> better system, put in temp sensors and use them to
> drop out the NiMH if necessary as well. I don't
> think
> it is necessary, but thats just me.
>
> Anyway, I may try that again and compare it to
> simply
> putting the Optimas in parallel. My bet is that the
> car will do a lot better with an equivilent amount
> of
> NiMH. And believe it or not, in this case the NiMH
> actually costs less!!! If you don't believe me,
> price
> it out. These are consumer grade D cells with max
> discharge of about 2 C rate. Build an equivilent
> pack
> of those to the capacity of 2 Optimas. At say 40 A
> discharge rate, the NiMH costs less!!! And, it
> lasts
> a lot longer. Two Optimas cost $320 and can give
> about 85 AH total (42.5 AH / ea). 21 x 4 x $4.50 /
> ea
> = $472. In some volume, the D cells could be bought
> in the $4 range, maybe less. That brings the total
> to
> $336 or less. So, maybe not exactly cheaper, but
> they
> probably last 2-3 times as long. Maybe not with my
> charge algorithm, but with an appropriate charger
> algorithm they would. Not to mention the weight
> savings.
>
> I'm open to thoughts and comments. What do other
> people think? What is the ideal solution for a car
> like mine? Taking into consideration performance,
> total lifetime cost, servicability, complexity, etc
> ...
>
>
> Steve
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End of EV Digest, Vol 6, Issue 98
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