Clueless take 2

Technical discussion on converting internal combustion to electric
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Post by T1 Terry » Fri, 08 Oct 2010, 05:52

Here goes,
My project is to try and adapt an electric drive to act as an assist on hill starts and big climbs and act as a partial brake by means of regenerative braking.
The vehicle isn't one of the usual choices, it's a 36ft Bedford bus being converted to a motorhome. Weight is a little unknown at the moment but between 7 and 12 tonne. I have converted it to rear engine, an LPG fuelled 351 Cleveland in place of the 500 Bedford diesel running through an Alison 4 sp auto trans. This gives me a place to mount my drive, via the PTO in the transmission but I will need to build a heavy duty unit with roller bearing to handle the load and continuous operation, I believe this is what Isuzu have done with their hybrid drive.
I have around 1kw of solar and 10 x 125ah 6v AGM batteries that are presently configured to 12vdc nom.
Here is a link to get a rough idea of the project so far.
Now for the technical questions, Is such a project feasible? What size, type, voltage motor/generator would suit such a project? What other bit will I need? Do I need my head examined for taking on yet another project?

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Post by Electrocycle » Fri, 08 Oct 2010, 13:16

I would say that the "best" way to do it would be to use something like a Tritium controller ($6k) and an AC motor on your PTO shaft or connected to the diff input via a belt / chain drive.

You would need to configure the batteries for a higher voltage to make it easy with an AC drive setup - which makes the solar charging a bit more difficult.

The nice thing about the AC motor is that it will work really well as a generator / regen brake system as well as giving high efficiency.


To do it on the cheap you could use a large DC motor for drive, probably running 48v (or whatever is the highest voltage you can easily set your solar panels up to charge) and add an alternator to the engine to charge the batteries (or even run a small separate generator.

You need to keep an eye on the amount of extra weight you're adding, or you might not end up with any real benefit, but it should work ok if done right.
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Post by T1 Terry » Fri, 08 Oct 2010, 14:01

How much assist am I likely to get via each system, if the AC is enough better then things can be adapted to suit. As usual the all up cost is a factor so costs of controllers and motors need to be considered to determine if it's really viable or just a pipe dream.
The PTO ratio to final drive changes with the auto ratio change so motor speed will not need to be huge, I'll possibly need to incorporate a drive cut off during shift change but these are minor technicalities. Is there a link to some where so I can learn a bit more about AC v DC, controller functions etc?

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Post by bga » Fri, 08 Oct 2010, 19:43

Hi Terry,

Given the weight of the bus, the electrics get epic to provide the amount of power and energy needed.

What about hydraulics and an accumulator?
There is a device called a "hydraulic launch assist" that charges an accumulator during braking and then releases it back to accelerate.

These systems make sense of garbage trucks (not comparing your bus to one Image) where braking is frequent. It probably also makes sense on an urban passenger bus, but probably not on an RV bus because most of the driving is outside the city.


*** Electrics ***

I have always liked the idea of a solar powered bus.
Covering the roof in panels should allow enough power to drive the bus around australia, provided that you are happy stopping freqently and for extended periods.

It's possible to estimate the energy requirement from the petrol fuel consumption:
Petrol contains about 9.3 kWh of total chemical energy and the engine is about 30% efficient at converting this to work, yielding mechanical energy equivalent of approximately 3kWh per litre of petrol.

Assuming that the bus burns 25 litres per 100km, 75 kWh of battery is needed to go 100km.
The bus probably burns more than this.
Some losses are experienced in a electric drive, but it's a lot better than 30%.
Some likely efficiencies are : motor (94%), controller (98%) and battery (95% LiFePo) efficiency, so probably 87% overall.
Comments?

On the charger side, if the bus is about 2m wide and, say, 8m long, 16 square metres is available for roof mounted solar panels. This translates to about 2.5kw of common solar panel. Under typical sun conditions, it would be reasonable to expect to collect 15 kwh of emergy, and probably 20 kwh, if the bus is repositioned during the day to allow the panels to track the sun somewhat.
This is approximately 20km per day.

A 75 kwh battery will weigh about 1 tonne in LiFePo cells, or 2.5 tonnes in lead acid. On a bus, this may not be too great a problem.

I would expect that motor with a 75kw continuous rating would be needed to maintain 80kph reliably.

There are some electric buses kin existence that would be good benchmarks.
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Post by Johny » Fri, 08 Oct 2010, 20:03

My 2 cents worth.
While this sounds really interesting I assume that the Bus will travel highway cycle most of the time. Previous post pretty much indicate that it would not be viable to have any electrics helping with highway travel (IMO In My Opinion).
If it was just to support start/stop when in urban areas then you could get away with a smaller motor, controller and battery pack. Essentially it would do a subset of what the Prius does and really only support braking energy storage for the next few take-offs. Gear the electric support so it was only effective up to say 50km/hr.

If the ICE is engaged all this time it would be difficult to image much gain though. The ICE would be continuous drag unless it could be made to track the electric motor's speed when in electric assist.

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Post by T1 Terry » Sat, 09 Oct 2010, 05:25

Thankyou all for your replies. I don't know if it would be practical to power a bus full time via batteries but it's an interesting thought. The major issues are hill starts and hill climbing so the electric assist would only be short term. The ICE can produce around 200kws but that is developed power not down in the lower revs. The bus will be as much off road as on the tar top so there will be occasions when low down torque is needed. I can achieve this by turbocharging the ICE but it places enormous strain on the rotating mass forcing additional torque at very low revs.
A DC motor would be the easiest to adapt but will a DC motor provide good torque or do I need to look at the complex set up of an AC motor?

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Post by Electrocycle » Sat, 09 Oct 2010, 06:03

a DC motor will certainly provide plenty of torque, but the size of motor required to make a worthwhile difference to the V8's torque will be pretty large.
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Post by EV2Go » Sat, 09 Oct 2010, 06:29

Check this bad boy here

Edit: fixed broken link
Last edited by EV2Go on Wed, 17 Nov 2010, 07:08, edited 1 time in total.

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Post by bga » Sat, 09 Oct 2010, 16:32

The problem with hill climbing is that it takes a lot of power to haul anything heavy up a hill at speed.

eg 10 Tonnes at 60kph on a 10% grade is something like 1.7m/sec of vertical climb, using e=mgh, we get 166kW to do the lifting. Air and mechanical drag adds to this.
A highway grade will be typically less than 5%, so the speed could be higher.

My guess is that the drive needs to be at least 200kW to climb a hill. nicely, probably a bit more more than the LPG 351 in your bus.

The original bedford 500 motor, was about 155 HP.

I'd be interested to know the fuel economy you get on typical open road conditions.

Cheers

[++ afterthoughts]
Regerative braking almost certainly means AC, as DC drives don't do regen very well, usualy not at all.

The real problem with the plan is the low utilisation that the *large* electric drive would have, making it not very useful most of the time or cost effective.

The fuel economy issues, which are acute in battery electric drives, points towards light weight construction and low drag designs to make the kWhs go further. Almost certainly aluminium / composite construction.

The speed will always be an issue because buses make big holes in the air and experience a lot of drag no matter how good the shape is. The power needed to overcome air drag is a 3rd order function; 8x the power is needed to go twice the speed.
Last edited by bga on Sat, 09 Oct 2010, 05:43, edited 1 time in total.
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Post by T1 Terry » Sat, 09 Oct 2010, 18:29

Hmmm.... The regenerative braking was one of the major requirements to make the project worth the effort. 20kw may be only 10% of the engines full power but likely more than 30% of it's available power off the mark or when lugging down on a higher gear. 20kw could well be the difference of climbing a hill one to two gears higher. 0 tonnes plus requires quite a large amount of braking to stop run away on a long down hill and a petrol engine driven through an auto trans with a torque converter in between doesn't offer a lot of engine braking so a lot would rely on the friction of mechanical brakes. A lot of heat and wasted energy, this was where I was hoping to regain some of the lost battery charge used on the climb.

The bus isn't on the road yet but figures from others that have similar conversions put the consumption between 2 and 3 km/ltr and liquid injection at around 4.5km/ltr. Unfortunately liquid injection is currently not available for my type engine.

Is the problem with DC regenerative braking an RPM issue?
What is the method of converting DC to AC? These motors appear to require amps way outside the range of the average inverter and I'm guessing PSW would be required.

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Post by bga » Mon, 11 Oct 2010, 00:34

Hi Terry,

Most of the DC motors are series wound. The field is in series with the commutator and rotor windings. The field windings take the full current throught the motor and are usually made of substantial copper bar, say 2 x 12mm, so there aren't very many turns. This type of motor has no permanent magents and is also called a 'universal motor' because it will turn the same direction if the battery polarity is reversed.

A principal advantage of the series wound design is that the field strength is proprtional to the armature current,even when being used at several times the makers rated maximum current. This makes the motor very easy to drive and control, which is why it's commonly used in DC drives.

Reversing of these motors is normally done by reversing the polarity of the field winding with respect to the armature via a pair of changeover contactors.

I have seen mention fo a few braking (regen) schemes using the changeover contactors, but these usually need a separate power supply for field to make the motor generate. I don't know of any EVs that do this.

Another way to go with (brushed) DC motors is sepex (SEParately EXcited). In these motors, the field is powered by a separate power supply. Usually, the field wire is much thinner wire and with many turns to keep the current at a reasonable level for a given field strength. The most common complaint about sepex motors in EV applications is lack of torque.

This is probably because field power supply reaches its limit on the field a long time before the armature reaches its limit. This effectively limits the output of the motor.
A Sepex motor can brake if the field current is raised sufficiently that the motor, the spinning motor EMF is greater than the battery voltage, at which point, energy will flow back to the battery. Normally the braking effect is lost at lower RPMs.

DC motors generally do not regenerate very well because they have to be turning fairly quickly to generate enough voltage to regharge the batery.


This is where 3PH induction motors (or permanent magnet motors) are vastly superior. With these motors, the field frequency (the three-phase AC 'mains') determines the speed of the motor. braking is accomplished by generating a field that is slower than the motor speed, causing it to slow the motor up. it is the exact reverse of the 'motor' part. THis is all in the controller and no extra hardware is needed to make an AC system do this. Many AC EVs will get effective regenerative braking down to 5 or 10 kph.

All EV AC Drives are variable frequency (VF) and use 3 pairs of very large transistors to switch the three phase outputs between battery+ and battery-. The clever controller pulses these to produce the needed sinusoidal AC current on the AC motor.
Any 'inverter' airconditioner or industrial VF drive has a DC bus inside that it switches to produce the required VF output. The bus voltage is about 300Volts on a single phase airconditioner and about 600V on a three phase industrial drive.

Look up AC Motor's project: Tuarn Brown's Suzuki SJ 40 for a very good example of a budget AC drive using off the shelf components.

You are correct, EV applications require large currents, large voltages or both, resulting in a enormous industrial VF drive being needed. A bus sized one would be at least as big as a 4 drawer filing cabinet, or a portable site toilet.

This is one reason I have opted for DIY on the controller. The currents and voltages make this a non-trivial exercise, however.

Another problem is that industrial AC motors are big and heavy,
I just had a look in the ABB catalog:
Aluminium 55 KW 4-pole (450mm wide x 880mm long, 297kg
355Nm rated torque, 950Nm for approx 30 seconds.
About $10K, I would guess.
About 93% efficient.

I would guess that an iron version of the above would weigh 450kg, which is getting heavy even for a bus.
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Post by Richo » Wed, 13 Oct 2010, 04:15

bga wrote: Assuming that the bus burns 25 litres per 100km, 75 kWh of battery is needed to go 100km.

I thought the idea was to be a hybrid.
He wouldn't need a big pack for assist only.
Think Prius setup...
bga wrote: Under typical sun conditions, it would be reasonable to expect to collect 15 kwh of emergy, and probably 20 kwh, if the bus is repositioned during the day to allow the panels to track the sun somewhat.
This is approximately 20km per day.

If you used 1kWh to help accelerate up to speed.
Then the petrol motor used to travel the distance.
Then 0.8kWh is recovered coming back to a stop.
You have only used 0.2kWh.
I would think 15kWh is on the large side for solar collection.
bga wrote: A 75 kwh battery will weigh about 1 tonne in LiFePo cells, or 2.5 tonnes in lead acid. On a bus, this may not be too great a problem.

I would expect that motor with a 75kw continuous rating would be needed to maintain 80kph reliably.

If the electric motor is an asist only then adding 100kW on top of the ICE would be plenty.
This is now something more like a 7.5-11kW Industrial AC motor.
And the battery capacity would be much less.
But if you were collecting 15kWh of solar then the batteries should be sized accordingly.
So 15kWh pack would also be more realistic.
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Post by Richo » Wed, 13 Oct 2010, 04:26

T1 Terry wrote: 20kw may be only 10% of the engines (ICE) full power but likely more than 30% of it's available power off the mark or when lugging down on a higher gear. 20kw could well be the difference of climbing a hill one to two gears higher.


So if I read this correct you could be happy with 20kW.
Now on an AC motor the max torque is from 0 RPM.
So the additional torque will be from take off.
Which is what you want.

Now 20kW from the AC motor would be the peak as you would not need this all the time.
So is would put the size of the motor around 5-7.5kW Industrial motor.
This could give 20kW extra take-off grunt and 20kW of regen.
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Post by Richo » Wed, 13 Oct 2010, 04:38

Now if you were using a 3kW industrial motor these are standard at 230V/400V.
So using this on a standard 400V controller but with the motor setup in 230V mode means you have picked up a 1.73 gain in nominal power in the motor.
So would be 5.2kW nominal and 15-20kW peak depending on brand/performance.
So these would be off the shelf parts.
If you want more than 20kW then you will need a bigger rewound motor to a similar 230V/400V setting.

Battery wise you would need about 48 x 12V batteries in series.
So at 15kWh useable capacity this is around 30Ah-40Ah per battery.

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Post by Richo » Wed, 13 Oct 2010, 04:51

Another thought also is the motor could go into optional regen whilst driving if the batteries get too low.
If it sucks off 3kW continuous - kind of like having the air-con on.
It would have recharged the batteries over 5 hours or so.
This is kind of like driving a bus Perth to Albany.
So by the time you get there the batteries are full for a nights fun of cooking/music/fridges/freezers/heaters etc.

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Post by woody » Wed, 13 Oct 2010, 06:15

Richo wrote: So is would put the size of the motor around 5-7.5kW Industrial motor.
This could give 20kW extra take-off grunt and 20kW of regen.
A 4 pole 7.5kW motor will only put out / take in 20kW from ~1500rpm up.

I.E. Power (kW) = torque (Nm) * rpm / 9550.

So you will want it connected to the motor side of the gearbox, or on its own reduction drive.

If it's on its own reduction drive, you'll want to disconnect it once you go over a certain road speed, or you'll spin it too fast and the rotor will let go.

If it's on the motor side of the gearbox you'll probably want to disconnect the V8 otherwise the V8 will compression brake some of your power instead of regenerative braking.

I think someone should do some sums along the lines of how much power you can reclaim decellerating a bus, and how much petrol you are likely to save on your round-australia trip by doing so.

cheers,
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Post by T1 Terry » Wed, 13 Oct 2010, 18:46

Thanks for all the replies
Richo wrote: Now if you were using a 3kW industrial motor these are standard at 230V/400V.
So using this on a standard 400V controller but with the motor setup in 230V mode means you have picked up a 1.73 gain in nominal power in the motor.
So would be 5.2kW nominal and 15-20kW peak depending on brand/performance.
So these would be off the shelf parts.
If you want more than 20kW then you will need a bigger rewound motor to a similar 230V/400V setting.

Battery wise you would need about 48 x 12V batteries in series.
So at 15kWh useable capacity this is around 30Ah-40Ah per battery.
I'm a little confussed now, if I could use a 230vac motor why do I need 576vdc nom battery voltage? Is the plan to use a single phase motor as 3 phase?
Richo wrote: Another thought also is the motor could go into optional regen whilst driving if the batteries get too low.
If it sucks off 3kW continuous - kind of like having the air-con on.
It would have recharged the batteries over 5 hours or so.
This is kind of like driving a bus Perth to Albany.
So by the time you get there the batteries are full for a nights fun of cooking/music/fridges/freezers/heaters etc.

This was in my line of thinking, ICE's have a range in which they are at the best energy efficiency, petrol/LPG engines in particular because light throttle means poor cyl filling and low compression. By loading the engine with the electric motor a better efficiency can be achieved and still have that reserve assistance there when it's needed.
woody wrote:
A 4 pole 7.5kW motor will only put out / take in 20kW from ~1500rpm up.

I.E. Power (kW) = torque (Nm) * rpm / 9550.

So you will want it connected to the motor side of the gearbox, or on its own reduction drive.

If it's on its own reduction drive, you'll want to disconnect it once you go over a certain road speed, or you'll spin it too fast and the rotor will let go.

If it's on the motor side of the gearbox you'll probably want to disconnect the V8 otherwise the V8 will compression brake some of your power instead of regenerative braking.

I think someone should do some sums along the lines of how much power you can reclaim decellerating a bus, and how much petrol you are likely to save on your round-australia trip by doing so.

cheers,
Woody

Where the PTO drives in the auto trans is directly related to the input/engine speed so over speed is not so much of a problem but something that will need to be kept in mind when calculating the ratio. As far as regen being effected by the ICE compression braking, this is more an issue with diesel engines than petrol engines because at closed throttle the compression is quite poor, add to that the drive loss through a torque converter working backwards and there is not a lot of compression braking, the PTO output is directly coupled to the input shaft speed so with the bus weigh at up to 12 tonne there will be plenty of energy to spare I think Image

I'm starting to get my head around what is required, most of the calcs still go way over my head but hopefully this will improve over time.
Thankyou everybody for your input sofar, panic set in initially but now after reading the red Suzuki thread I'm getting a bit of an understanding of what I’d be in for so I'm still hanging in there.
The high voltages associated still have me a little concerned, I have a healthy repect for 240 vac and an even healthier respect for DC voltage, a battery terminal will vaporise at 24v with a poor connection, I can’t picture what would be required to break a circuit running at 288vdc with the full potential of the battery capacity behind it.

This brings me to the next issue, these voltages are in the licensed electrician area aren’t they? That would rule me out of working on my own project wouldn’t it?

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Post by Richo » Wed, 13 Oct 2010, 20:53

woody wrote:
Richo wrote: So is would put the size of the motor around 5-7.5kW Industrial motor.
This could give 20kW extra take-off grunt and 20kW of regen.
A 4 pole 7.5kW motor will only put out / take in 20kW from ~1500rpm up.

I.E. Power (kW) = torque (Nm) * rpm / 9550.
Yes but it is the torque that is required which is max and flat to ~1500RPM.
Which is what Terry wanted to give extra acceleration.

woody wrote: If it's on its own reduction drive, you'll want to disconnect it once you go over a certain road speed, or you'll spin it too fast and the rotor will let go.
There is that possibility.
But I would want to see gear/diff ratio's before I say that is possible.
woody wrote: If it's on the motor side of the gearbox you'll probably want to disconnect the V8 otherwise the V8 will compression brake some of your power instead of regenerative braking.
Yep that could happen.
But for cost sake I would leave the V8 connected with the ACIM too.
The compression braking would not be that much to get to concerned about.
woody wrote: I think someone should do some sums along the lines of how much power you can reclaim decellerating a bus, and how much petrol you are likely to save on your round-australia trip by doing so.

Yep that's where I'd be headed - to the calculator that is Image
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Post by Richo » Thu, 14 Oct 2010, 03:55

   
Richo wrote: Now if you were using a 3kW industrial motor these are standard at 230V/400V.
So using this on a standard 400V controller but with the motor setup in 230V mode means you have picked up a 1.73 gain in nominal power in the motor.
So would be 5.2kW nominal and 15-20kW peak depending on brand/performance.
So these would be off the shelf parts.
If you want more than 20kW then you will need a bigger rewound motor to a similar 230V/400V setting.
T1 Terry wrote:I'm a little confussed now, if I could use a 230vac motor why do I need 576vdc nom battery voltage? Is the plan to use a single phase motor as 3 phase?

Sorry no.
A 3kW 3-phase motor runs from 3-phase 230Vac@50Hz@1500RPM while in delta mode.
576Vdc through a motor controller will produce about 400Vac 3-phase.
So the 3-kW motor can now produce 5.2kW@400Vac@86.5Hz@2595RPM continuously.
But on peak demands the controller can apply more current to get more torque and thus more power ~20kW.

As you can understand most electric supplies on 230/240V shouldn't be pulling more than 3kW.
So motors bigger than 3kW are designed to run on 400Vac in delta mode.
So a 4kW motor connected to a 400Vac controller will only produce 4kW.
To get more power out of the 4kW motor you have to ask a rewinder or the manufacturer for a special winding voltage ie 230Vac.
But this costs more.
SO if you are after 20kW a 3kW motor running on 400Vac will be cheaper than a 4kW with a custom wind job on it.

Quirk of the motor industry I guess.

You could go all out and standardise the voltages on your bus.
Now if you want to run 240V appliances you will need:-
1. 12Vdc run through a DC-DC / inverter to produce 240Vac
2. 340Vdc run through an inverter to produce 240Vac.

The question is it cheaper to get 1. or 2.

In 1. you will need an isolated DC-DC to convert the traction pack to 12V to supply the 12V to the DC-DC/inverter to produce 240Vac.
In 2. you only need the 340Vdc inverter to produce 240Vac.

1. uses typically off the shelf parts.
2. custom inverter.

But now if you do use a 340Vdc traction pack the motor must be rewound to 140Vac to get the same ~20kW peak power output.
We are only talking $500-900 for a rewind but money is money right.
And it is easier to get hold of a 340Vdc to 12V DC-DC converter with a 140vac rewound motor than a custom 576Vdc to 12V DC-DC converter or custom 340V dc to 240Vac inverter.
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Post by Richo » Thu, 14 Oct 2010, 04:11

In any case it will probably work out cheaper and easier to have a 3-phase motor setup to ~140Vac in delta mode.
So it won't really matter which size you pick because it is a custom job any way.
I would expect any self respecting rewinder could do this job for you.

This sets you pack for around 340Vdc.
Which simplifies the conversion from the traction pack through 12V bus battery to the 240Vac inverter to supply appliances.

List of parts so far:
1. 3-phase motor 3kW-7.5kW wound to ~140Vac in delta.
2. 25-65HP 230Vac 3-phase inverter with torque control mode.
3. 500W-1kW 240Vac(340Vdc) to 12V isolated switch mode power supply
4. 2.5-3kW 240Vac pure sine wave inverter.
5. ~340Vdc traction pack

Not too sure of any off the shelf parts for the solar cells to recharge the 340Vdc traction pack directly.
And there is no point recharging a 12V bus battery from a 1-2kW solar system.

And as Woody points out motor placement still is an issue.
Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

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Clueless take 2

Post by T1 Terry » Sat, 16 Oct 2010, 13:09

Thanks heaps for your input so far, slowly getting my head around this stuff. I'm guessing the 340vdc battery pack is a nom voltage, if I use agm batteries 7 packs in series of 4 x 12vdc batteries(48vdc nom) would give me 336vdc nom, fully charged 358vdc but to recharge would require 405vdc via regen, is all this with the range of the 3-phase motor setup to ~140Vac in delta mode?
If I connect the 7 packs so they can also be joined in parallel I can still charge the via solar and use an off the shelf 240vac inverter/charger, if I'm on a powered site for any reason I may as well get my monies worth.
More questions, as this will be a hybrid set up, how do I control the electric motor to deliver contolled assistance at one point and the regen braking at another point while still operating the ICE throttle and brake as normal? Is it possible to adapt a vacuum operated control set up so at a set point there is no assist no regen, a lower vacuum would produce assist on a sliding scale and at higher vacuum regen on a sliding scale? Does such a unit exist?

The 7 x 48v battery packs, on regen they would be in series so recharging isn’t so much of an issue but when in parallel is there a commonly available method of equalising the charge rate between all seven battery packs or is this really not necessary?

T1 Terry
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Clueless take 2

Post by T1 Terry » Mon, 15 Nov 2010, 01:35

Ok, is this the type of motor I'm looking for? What are the dramas/pitfalls to look out for getting stuff from the states?

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Clueless take 2

Post by 7circle » Mon, 15 Nov 2010, 08:02

Compare the spec's and price.
You need a synchronous controller too.
I wonder if the Wavesculpter could control it or two of them with locked spindles to the Diff.

The Name plate looks quite helpful
Image

The motor with fins looks pretty retro. The small name plate makes the motor look huge.
Image

The Redrive used CNC supplier I think might be making a killing on these part for companies with breakdowns.

I'm sure you can find a cheaper than "only $4274.00" 7.5kW/11kW Spindle motor.

At around 68Kg (150lb) shipped that's a bit to big.

I just posted a similar motor [url=viewtopic.php?p=29542&t=2229#p29542] here on AC Amping it Up[url]

Its a bit dirty but looks newer technology and high power at 15 / 18.5 KW but at high RPM. But its only $800 on Ebay.

I noticed a huge sale of machinery at Holden's Fishermens Bend. It was a pdf of the auction list. I'm sure they had pallets full of such motors.

AC Motor mad some comments just below that post comparing his motor an Induction type.

The controller will need to have plenty of voltage above nominal to get it to run hard at high revs even for 1 min spurts at the lights.

As cars are travelling fast you can use plenty of wind cooling.

So temperature monitoring of motors would be very helpful.
Some really smart controller may evaluate the increase in the motor resistance to protect for over temperature too.

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Clueless take 2

Post by Johny » Mon, 15 Nov 2010, 14:24

IMO That spindle motor is not suitable for an EV. It's rating of 11kW at over 5000 RPM is no-where near what you would get from a rewound 4 pole, 11kW, 72kg Induction motor. I am estimating around 67kW from my Taiwan motor at 4500 RPM. It cost AU$750 with upgraded insulation, external fan, encoder (shipping is another matter). The ABB motors some of the guys are using are only costing around AU$1200 landed here!

It's also way to expensive and you haven't even looked at shipping yet.

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Clueless take 2

Post by T1 Terry » Mon, 15 Nov 2010, 14:58

Thanks 7 Circles and Johny, it wasn't that particilar motor but the type I was refering too as it is a 4 pole 3 phase wired for 113v to 169v. There is a pallet of motors apparently up near Newcastle in a spares yard but without knowing what I looking at I'd be wasting my time, they just look like big ones and small ones to me :lol: ICE engines is my line of expertise.

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