valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Tue Apr 08, 2014 8:45 pm

Kris1 wrote:So early adopters would need to buy a separate programmer for firmware upgrades Valery?
no, we supply programming cables with all our products on request.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

Kris1
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Wed Apr 09, 2014 9:36 pm

So what price on a 45kw chademo box that runs from 360v DC input instead of 3 phase mains Valery?

valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Wed Apr 09, 2014 11:27 pm

Kris1 wrote:So what price on a 45kw chademo box that runs from 360v DC input instead of 3 phase mains Valery?
Hi Kris - Please check out these products on our site (not everything is fully available for shipping yet but we are taking pre-orders):
* http://emotorwerks.com/products/online- ... fc-charger" onclick="window.open(this.href);return false;
* http://emotorwerks.com/products/online- ... c-chargers" onclick="window.open(this.href);return false;
* http://emotorwerks.com/products/online- ... c-chargers" onclick="window.open(this.href);return false;

This combination should work up to 40kW from a DC source. The only limitation of this combination is that your output voltage will be higher than input voltage at all times. Therefore it will generally work with Leaf above ~30% SoC (if from 360VDC). Depending on your usage, this might or might not be ok. Please let me know about your use case.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

Kris1
Posts: 47
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 4:55 am

I didn't realise there was such a tight link between DC supply voltage & Leaf battery voltage Valery;
1) Is there some chargers-for-dummies primers for this technology you could suggest for me to read?
2) With a 415v~ 3 phase version, would the DC peak be 587v after rectification? If so how are you able to charge a Leaf pack with such a high DC source voltage?

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TonyWilliams
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 11:19 am

Kris1 wrote:I didn't realise there was such a tight link between DC supply voltage & Leaf battery voltage Valery;
1) Is there some chargers-for-dummies primers for this technology you could suggest for me to read?
2) With a 415v~ 3 phase version, would the DC peak be 587v after rectification? If so how are you able to charge a Leaf pack with such a high DC source voltage?
The AC input voltage has very little to do with the DC output. There are DC chargers operating on 200v, 208v "single" and three phase, 220v (380 volt three phase), 230v (400 volt three phase) 240 volts, and 277 volts per three phase (480 volts), and 348v (600 volts).

Did I miss any?

valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 1:15 pm

TonyWilliams wrote:
Kris1 wrote:I didn't realise there was such a tight link between DC supply voltage & Leaf battery voltage Valery;
1) Is there some chargers-for-dummies primers for this technology you could suggest for me to read?
2) With a 415v~ 3 phase version, would the DC peak be 587v after rectification? If so how are you able to charge a Leaf pack with such a high DC source voltage?
The AC input voltage has very little to do with the DC output. There are DC chargers operating on 200v, 208v "single" and three phase, 220v (380 volt three phase), 230v (400 volt three phase) 240 volts, and 277 volts per three phase (480 volts), and 348v (600 volts).

Did I miss any?
It all depends on how you build it.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

Kris1
Posts: 47
Joined: Fri Feb 28, 2014 10:38 pm
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Leaf Number: 200165
Location: Sydney Australia

Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 5:07 pm

So, in terms of the Leaf pack voltage & the charger supply voltage, there is flexibility in an AC powered charger's design not present in a charger running from a fixed voltage DC supply?

valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 6:00 pm

Kris1 wrote:I didn't realise there was such a tight link between DC supply voltage & Leaf battery voltage Valery;
1) Is there some chargers-for-dummies primers for this technology you could suggest for me to read?
2) With a 415v~ 3 phase version, would the DC peak be 587v after rectification? If so how are you able to charge a Leaf pack with such a high DC source voltage?
Sure thing.

In order to understand the below, you need to know that cost reduction and high efficiency were some of our main design criteria for these chargers.

Normally, you would see a standard 2-stage charger topology - an up-converter (aka boost stage) followed by a down-converter (aka buck stage). See more 101 info at http://en.wikipedia.org/wiki/Boost_converter" onclick="window.open(this.href);return false; (scroll down to related links for info on other topologies). The advantage is truly universal input and output voltage - generally both can range from 0 to close to upper limit on devices used to build these - practically limited to ~450VDC output for standard elcaps and semiconductors. The downside is that you have twice as much hardware, weight, cost, and heat as a single stage unit would have.

Hence our high-power chargers are all single-stage converters. That means that there is now a restriction on the output voltage relation to the input voltage. Boost topology would have a MINIMUM battery voltage = MAXIMUM input voltage you expect. Buck topology would have a MAXIMUM battery voltage = MINIMUM input voltage your expect to see MINUS about 20-30V.

For your practical example of 360VDC input, this means that your output could either be 0-330VDC or 360VDC-450VDC (upper limit can be raised by using different parts inside - we have custom units operating at 900VDC output for some customers...). In reality, the valley between these ranges is even larger due to the likely voltage sag on your source at load. Say, you use a RAV4 battery to charge your Leaf. The battery could easily sag to ~330V from 360V when you load it with 25kW. But it will jump back to 360 if you remove the load. This means that your lower limit on Leaf battery voltage in boost configuration is probably still 360VDC but your upper limit in buck configuration is now 30V lower, or 300VDC.

Unfortunately, this 'valley' covers the bottom 15-20% of Leaf battery SoC. Which means that it would be hard to charge a Leaf from dead zero with a single-stage boost charger off 360VDC input. Obviously, buck is not useful at all as it would not be able to cover any meaningful part of the SoC range for a Leaf pack.

So there are two ways to solve this: 1) go back to dual-stage charger (such as our 12kW SmartCharge units - note half the power of the single-stage - exactly due to the reasons above), or 2) change your input voltage - e.g., by adding an AUX battery to bring the voltage up, etc.

Or, of course, you can just live with the limitation of not being able to charge a completely discharged Leaf.

Valery.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Fri Apr 11, 2014 6:18 pm

Kris1 wrote:So, in terms of the Leaf pack voltage & the charger supply voltage, there is flexibility in an AC powered charger's design not present in a charger running from a fixed voltage DC supply?
Again, all depends on the specific charge design. Generally speaking, same restrictions apply but they are now relative to the peak amplitude of the AC wave - or 1.4 * [input RMS voltage]. For 240VAC input, this amplitude is 336V. So a boost-based design would be able to deal with the battery above 330V. According to http://www.mynissanleaf.com/viewtopic.p ... 79#p141691" onclick="window.open(this.href);return false;, 330V = ~4% SoC on a Leaf pack and is very close to Turtle mode. So there is very little practical limitation to a boost-based design running from 240VAC supply.

Note that all these considerations apply largely to non-isolated units only (doesn't matter much if your input is DC from battery). Voltage on isolated units can be adjusted relatively arbitrarily.

Hope this makes sense.
EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

valerun
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Re: Mini-QC Rapid-Charger (RC) Project for LEAF QC Port

Sat Apr 12, 2014 4:48 pm

valerun wrote:
GregH wrote:
valerun wrote:We would have: 8 ADC, 16 digital, 4 CAN, 6 UART, 4 SPI, 6-8 programming / power.
And that's not overkill?
not really. note that numbers are PIN counts, not port counts. E.g., 4 CAN pins are just 2 CAN channels, 6 UART pins are 3 UART channels.

In our chargers, 5 analog pins are used in a basic configuration (input voltage, output voltage, output current, heatsink temp, inductor temp). Plus 8-10 digital pins are used. So with 8 analog and 16 digital we are just building a small amount of headroom.

re overkill on a chip side - CAN + WiFi + basic charger operation takes ~120KB in flash footprint already - and that's before we handle any bidirectional comms and user auth workload...
so... laying out a 144-ball LFBGA has proven to be a bit challenging ;-)

So we have done a first pass at the micro-Due board using a 144 LQFP package (same as in a Due). V0 below (edited since original post to add an EEPROM 64kbit chip and a few other things). Would appreciate feedback from any embedded gurus who could be lurking here...

Will try to get this finalized in the next 7 days. Our PCB house confirmed that they can build this. Should be fun.

V
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EMW - Creators of the Best-Selling 10-18kW JuiceBox EVSE: http://emotorwerks.com/, JuicePlug - a universal adapter to make any EVSE smart: https://goo.gl/dM29O7, and 12-50kW DC Charging systems: http://goo.gl/oOpBvq

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