[Technologic]

First off this is not a joke or anything. For our senior design project we are required to build a battery charger for an electric van.

A little background - our university has a student transportation system, which consists of 15-passenger Ford E-350 vans that drive around campus from 5 PM to 3 or 4 AM, allowing students to catch a ride home late at night without risking getting mugged, etc. The vans drive about 100 miles each night, and with all the idling they get about 4 MPG. A few senior design groups decided to take on the daunting task of converting one of these to an all electric vehicle. Our group is tasked with building the charger, other groups are working on the battery management system and user interface.

The design currently includes a 400 Volt motor and controller (yes, 400!). For the battery pack, we were looking at getting about 100 Saft 41 A-hour lithium ion batteries. The decision to use LI-Ion is based on weight and power density requirements.

Basically we are looking for any expertise on where we could buy a charger that would be able to charge a 400V, 20(ish) Amp pack, or if we are going to be best off building it ourselves, etc.

Thanks in advance!

eLIMO Charging Team

400v x 20 amps won't meet your range needs. Also you will definitely be designing a charger for this...

Luckily chargers are very simple... just find a large 450v or so toroidal transformer for it.

 

[david85]

Technologic is right about the range.

The first thing I have to ask is what is your budget? A 15 passenger van needs a lot of energy reserve to make it past 100 miles on one charge even if you never break 30 MPH.

 

[rhensley01]

What electrical engineering and software personnel do you have available?

Do you have a load bank and power line monitoring/analyzer equipment?

Are you going to use a PFC boost circuit followed by a full wave bridge circuit follwed by a forward converter circuit?

A 400VDC and 20A output charger is an 8KW output charger. This charger would require a 60A, 240VAC circuit. A 5.4KW charger can use a 30A, 240VAC circuit. A 30A, 240VAC circuit is typical for an electric dryer or AC condensing unit. This circuit is usually available in a home garage. A 60A, 240VAC is typical for a welding machine. All this assumes a single phase service. A typical 5.4KW charger output is 320VDC. You may want to consider 320 VDC system.

Also, inductors and planar transformers are available for a 5.4KW circuit. A 8KW charger would require custom inductors and transformers (ie expensive)

If you want futher discussion, my e-mail is [email protected]. I am a member of the Tucson Electric Car Club.

 

[Guest]

I question the validity of this post. First you state you are required to build a charger but then you talk about buying one. That is not conducive of building as a requirement for your class. Buying one will do nothing to further the knowledge that research and building one would do. I suspect you will need to build one and to build it according to the type of batteries that will be used. Just using a transformer will not do for lithium. I suspect this post.

First off this is not a joke or anything. For our senior design project we are required to build a battery charger for an electric van.

A little background - our university has a student transportation system, which consists of 15-passenger Ford E-350 vans that drive around campus from 5 PM to 3 or 4 AM, allowing students to catch a ride home late at night without risking getting mugged, etc. The vans drive about 100 miles each night, and with all the idling they get about 4 MPG. A few senior design groups decided to take on the daunting task of converting one of these to an all electric vehicle. Our group is tasked with building the charger, other groups are working on the battery management system and user interface.

The design currently includes a 400 Volt motor and controller (yes, 400!). For the battery pack, we were looking at getting about 100 Saft 41 A-hour lithium ion batteries. The decision to use LI-Ion is based on weight and power density requirements.

Basically we are looking for any expertise on where we could buy a charger that would be able to charge a 400V, 20(ish) Amp pack, or if we are going to be best off building it ourselves, etc.

Thanks in advance!

eLIMO Charging Team

 

[Technologic]

Just using a transformer will not do for lithium. I suspect this post.

I didn't mean just a transformer (since that would still be AC) I was just being facetious about the things he'd need and named the most expensive part

 

[Technologic]

A 400VDC and 20A output charger is an 8KW output charger. This charger would require a 60A, 240VAC circuit. A 5.4KW charger can use a 30A, 240VAC circuit. A 30A, 240VAC circuit is typical for an electric dryer or AC condensing unit. This circuit is usually available in a home garage. A 60A, 240VAC is typical for a welding machine. All this assumes a single phase service. A typical 5.4KW charger output is 320VDC. You may want to consider 320 VDC system.
.

Is it necessary to have an 8kw charger on an 8kwh battery pack? or am I missing something here?

why can't the charger be a 2kw one and charge in 4 hours?

 

[Guest]

I didn't mean just a transformer (since that would still be AC) I was just being facetious about the things he'd need and named the most expensive part

Ooooooop's did not catch that one!