[valerun]

Originally Posted by 1-ev.com

Damien,
I have a question: Have you manufactured cooling plate yourself or purchased it from someone?

What is the size?

Do you have any pics how it looks inside?

Thank you.
-Y

Not sure about Damien's, but I found good single-pass plates on ebay for ~$110 shipped (8x12", with 8x11" usable space). These are designed for bars to cool liquids etc. They need to be milled flat which is not a big deal..

[jackbauer]

That chill plate I just happened upon on ebay from a surplus supplier. It came a with a couple of 3 phase solid state relays! I haven't looked at the rtc just yet. Been busy with work stuff. I usually charge in the early morning from approx 4am so it would be ideal to use the waste charger heat to warm the passenger cabin and demist the windows.

Purchased this radiator :
http://www.ebay.co.uk/itm/3803543373...84.m1439.l2649

Its designed for two 120mm fans or will fit neatly into the heater matrix housing on the bmw.

[1-ev.com]

Originally Posted by valerun

Not sure about Damien's, but I found good single-pass plates on ebay for ~$110 shipped (8x12", with 8x11" usable space). These are designed for bars to cool liquids etc. They need to be milled flat which is not a big deal..

Valery, thank you. Are those for liquid cooling?

I have CNC-lathe, so I can make my own. I was thinking to buy already manufactured, it should be cheaper...

-Y

[valerun]

Originally Posted by 1-ev.com

Valery, thank you. Are those for liquid cooling?

I have CNC-lathe, so I can make my own. I was thinking to buy already manufactured, it should be cheaper...

-Y

Yes, normally used to run liquid to be cooled inside the plate, while plate is immersed in ice. Typically used in bars etc to chill water, coke, etc for drinks ;-)

[aeroscott]

Nice looking exchanger . I'm thinking about separating some of the cooling system for reliability reasons , maybe just a few valves or plugs , tees and a little hose with clamps for that down on the side of the road . maybe overkill ?

[Jan]

I've a quetion about single phase. First I thought 230Vac is 325Vdc. But if I look at this wiki I get confused:

http://de.wikipedia.org/w/index.php?...20110126205058

Thist is a graph of three phase, and it shows a max voltage difference between a phase and neutral of +325V to -325V. I thought single phase power is just one phase of three phase power.

In my limmited understaning I expect, if I connect a single phase to a rectifier bridge and a capacitor, a potential difference of 650Vdc? What am I missing?

[jackbauer]

230v is the rms value. It actually swings +/- 311v if memory serves. Rectified 230v typically results in an on load dc bus of about 310vdc.

[Jan]

Originally Posted by jackbauer

230v is the rms value. It actually swings +/- 311v if memory serves. Rectified 230v typically results in an on load dc bus of about 310vdc.

230V is the rms (root 2) of 325V, but... between neutral and one phase there is never more than 325V difference. Negative and positive. So I can understand that from an AC point of view it's 230V rms. It doesn't care if it is 0-230V+ or 0-230V-, the difference in rms is 230V.

But rectified and connected to a capacitor the currenct can never reverse, so at the positive end of the capacitor the voltage will rise to 325V+ and at the negative side it will become eventually 325V-, making a potential difference of a whopping 650V... Not?

[valerun]

Originally Posted by Jan

230V is the rms (root 2) of 325V, but... between neutral and one phase there is never more than 325V difference. Negative and positive. So I can understand that from an AC point of view it's 230V rms. It doesn't care if it is 0-230V+ or 0-230V-, the difference in rms is 230V.

But rectified and connected to a capacitor the currenct can never reverse, so at the positive end of the capacitor the voltage will rise to 325V+ and at the negative side it will become eventually 325V-, making a potential difference of a whopping 650V... Not?

you can get 650VDC out of 230VAC if you 'catch' the top of the positive sinusoid half with one diode and the bottom of the negative half with another diode. That's how the voltage doubler works. For schematics, check out our charger schematics at http://www.emotorwerks.com/cgi-bin/VMcharger.pl.

[valerun]

Quick update.

Fully assembled 10kW PFC charger tested on our new BMW conversion for a couple of full charges (32A CC, 311V CV). Still air cooled and still on a 10x8" heatsink but took an 80W automotive radiator fan. With speed control depending on temperature so relatively efficient.

In the new layout, everything (including a heatsink) is enclosed in a 11x12x8" steel box. This way, nothing is sticking out and fan runs air in the box, preventing any hotspots for the components not on the heatsink.

Seems that 11x12x8" is the right size for this charger with air cooling. ~10W / in^3.

Will post more pics detailing assembly soon.

Also started working on a modular design inspired by the VICOR modules. Would love to get your feedback on the overall system design.

There will be the following modules one could assemble / buy kits for:
1. Control module providing all the supply voltages, gate drive signal, and LCD. It will be taking in thermistor inputs and voltage / current inputs
V from slave modules.
2. 3kW 400V PFC module. Mounted inside a milled aluminum heat spreader, with built-in thermistor.
3. 3kW 20A buck charger module. Mounted inside a milled aluminum heat spreader, with built-in thermistor and gate input.

At 3kW, these could be based on smaller IGBTs and run at 30-50kHz, reducing the size of the modules further.

Both PFC and buck heat spreaders will be designed to be connected either to a finned heatsink for air cooling or chill plate for liquid cooling.

A user would be able to connect arbitrary number of buck modules in parallel using the same gate drive. A PFC module can be connected to each buck module to get the proper PF correction if desired.

The only open question is whether to do the isolation at the PFC stage. If yes, how exactly.

Any thoughts?

V