Utility Direct Fast-charger Technology for EVs

[Smidge204]

This story is from February/March but I'm only just learning of it through the April edition of Powergrid International trade mag. A new type of DC charger system has been demonstrated which runs directly off of the utility distribution grid (demo unit input was 24,000 volts ) eliminating the need for a dedicated step-down transformer and thus improving efficiency.

Here's a link to an older, more detailed article and a link to the article I learned about it from...

http://www.greentechmedia.com/articles/read/the-universal-transformer-as-ev-fast-charger/

On top of that, EPRI’s system is built to connect relatively simply to medium-voltage distribution lines, compared to the multiple transformers needed to convert that power to voltages suitable to DC fast charging, Maitra said.

The charger seems to cost ~$30,000 right now, but it eliminates $20,000-$30,000 in other equipment.

http://www.elp.com/index/display/ar...ring-capacity-for-power-quality-products.html

EPRI used a Nissan Leaf and Mitsubishi iMiEV in Knoxville to demonstrate the communication capability of this fast-charging technology with EV battery management systems. A user interface and Web-based mobile data collection system also were included in the demonstration.

sodnus like it's CHAdeMO compliant :lol:


The idea is pretty posh and could really simplify (and reduce cost of) charge station installation by eliminating most of the traditional upstream electrical components. Smaller physical footprint, faster and cheaper installation. Awesome.
=Smidge=

 

[JeremyW]

Nice! Much better then the 208V, ~156A Eaton units. Less current, less transformers, less loss, more charging!

Except...

A utility that wants to provide fast-charging capability directly from its distribution system. This could be useful in dense cities where fast chargers are placed that are not hosted by a business.

That won't fly in CA until the CPUC changes their tune. Utilities here can't be involved in providing charging directly. They can provide you with the necessary kV service, but I'm not sure how that's set up right now. Usually only high power customers would take distribution voltages directly. Maybe Randy can comment.

Here's to the future though!

Jeremy

 

[edatoakrun]

I believe most, if not all, utilities regularly discount charges to large-demand customers who receive their kWh at higher voltages, so this would seem to be a very useful improvement in the future, for large scale DC charge stations, where many BEVs are charging at high rates simultaneously, by both lowering costs and increasing charge efficiency.

How well utilities will use it, particularly within CPUC controlled regions, is a very good question.

 

[EricH]

California utilities offer voltage discounts to large users, that make up for the transformer losses the utility would suffer by lowering the voltage prior to delivery. The major discount occurs at 50kV, as shown in the SCE's GS-1 tariff sheet:

http://www.sce.com/NR/sc3/tm2/pdf/ce143-12.pdf

By and large these do not appear significant (less than 1.5 cents/kWh, even at the highest voltages) enough to offset summer on-peak demand costs.