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AC motor and current consumption

5570 Views 10 Replies 5 Participants Last post by  EVmot, 
E
Hi to all.

I'm converting my Ford, from 1990, to EV.
The motor that am using is AC cage motor.

Technical info:
VEM motor - 11 or 13KW connection
1850 RPM
Car weight : 770 kg ( without batteries )
AC controler : Siemens 40KW ( 200- 450V DC input )
Battery bank: 15KW ( at least )
Transmission is kept and the motor is connected to this transmission.
5 gear transmission.
Car weight after battery installation - max 850 kg.
Battery's will be homemade.

Questions:
- before i design battery bank i need to find out how much current can this AC motor drawn on let's say highest consumption. First gear etc. ?

- can i set 300VDC at 50 Ah. Will this be enough current ?

- based on this design, what do you think, can i reach speed of 100 km/h ?

Thank you in advance.
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peggus
300Vdc at 50Ah is a measurement of energy, should give you about 30-40 miles in a typical conversion.

The motor can draw as much current as your inverter can deliver.

With 40kW and light car the odds are pretty good you can reach 100km/h
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E
What type of Ford?

I am using a siemens motor rated 280A AC, and the max current I see from the battery is roughly the same, 280A DC.

Assuming your 40kw inverter is your limiting factor, I would plan on sizing your pack for atleast 40kw. I'd shoot for 120A @ 330V. Above 330V it gets tough to find DC-DC converters.

Is the inverter tuned to run the VEM motor?

My car will do 100km/h using 20kw, but you will want some overhead for hills and you don't want to be running 100% all the time. I think 40kw is about right if you have a small car.





EVmot said:
Hi to all.

I'm converting my Ford, from 1990, to EV.
The motor that am using is AC cage motor.

Technical info:
VEM motor - 11 or 13KW connection
1850 RPM
Car weight : 770 kg ( without batteries )
AC controler : Siemens 40KW ( 200- 450V DC input )
Battery bank: 15KW ( at least )
Transmission is kept and the motor is connected to this transmission.
5 gear transmission.
Car weight after battery installation - max 850 kg.
Battery's will be homemade.

Questions:
- before i design battery bank i need to find out how much current can this AC motor drawn on let's say highest consumption. First gear etc. ?

- can i set 300VDC at 50 Ah. Will this be enough current ?

- based on this design, what do you think, can i reach speed of 100 km/h ?

Thank you in advance.
Click to expand...
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E
300Vdc at 50Ah is a measurement of energy, should give you about 30-40 miles in a typical conversion
* OK. Thank you.

What type of Ford?
* Ford Fiesta

Assuming your 40kw inverter is your limiting factor, I would plan on sizing your pack for at least 40kw.
* I was planning on 30KW max but OK i can try to push it up to 40kW.

Above 330V it gets tough to find DC-DC converters.
* Why do i need DC-DC inverter ? If i can create 300V/120A battery, then i dont need any converter. Or ?

Is the inverter tuned to run the VEM motor?
* Yes.

My car will do 100km/h using 20kw,
* can you share some additional info on this ?

Btw. my AC inverter
* Siemens Midimaster 6SE3226-8DJ40
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E
The DC-DC converter is to supply 12v to run the cars accessories.

My conversion was a 2001 Passat, 3700 lbs. I'm sure your car will require quite a bit less power!

Have you got pictures of your conversion? Here is a link to mine: http://etischer.com/awdev/
cheers
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E
The DC-DC converter is to supply 12v to run the cars accessories.
* Upps :) Sorry for misunderstanding. This part will be separated from main power bank.

Have you got pictures of your conversion? Here is a link to mine: http://etischer.com/awdev/
* i will put few pictures next week because then i will be done with motor part.

I have few questions but i will send them later....

Gotta go.
Hear ya !
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madderscience
Did you say homemade batteries?

More info please :)
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E
@ etischer
Hi ! :) Nice photos.
Can you tell me what kind of motor and what kind of controller did you use.

What do you think, how much current would be needed in my case.
I'm asking for current value because i can define the voltage with water solution. So, if i want to make my own battery i need to know how to set the solution. It's simpler too make higher voltage then higher current
Basically, battery design is the main key.

@madderscience
I use two approaches. Zinc - air and ALU-air.
http://www.charlesedisonfund.org/Experiments/HTMLexperiments/Chapter2/2-Expt8/p1.html
http://exo.net/~pauld/activities/AlAirBattery/alairbattery.html
http://www.youtube.com/watch?v=SPXhNnMkpe8

You can find more info on overunity.com

By for now.
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E
One more question.
Now when the plate and bearings part over is, i have to make a project for motor holder. Can you give me some suggestion what would be the best way to stabilize the motor. I was planning on using 4 connections points.

http://tinypic.com/view.php?pic=2lm0uc6&s=6

Idea:
http://tinypic.com/view.php?pic=29lbtbm&s=7

Suggestion ?

Thank you in advance.
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P
Hi !

Are you baking your own aircathode or buying something?
There is a pretty long thread on the swedish forum on this subject.
But it is in swedish of course.
google will translate for you....

http://translate.google.co.uk/trans...tp://www.elbil.forum24.se/elbil-about844.html

Regards
/Per
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E
Are you baking your own aircathode or buying something?
** I'm baking it. If you are planning to make something like this then it's far batter to make all on your own.

It's important to say that im not using the acids that is used in Swedish design ( NaOH ). Im using saltwater and some other very weak acid.

I can get over 800mA per one cell, at 1,2V.
If you would use strong acids you can get over 2A per cell.
I have no idea how did they get 300A.

The main problem that i'm facing wright now is the stability of the battery.
After cca 30minutes the capacity falls to 50% but there is way how to repair this.

btw. how to disable the e-mail notification that i get each time someones sends reply?
I disabled mostly all in the edit option part, but that's not working.
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