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EV Charging Expansion and Voltage Limitations

Discussion in 'North America' started by quantumslip, Mar 17, 2018.

  1. quantumslip

    quantumslip Member

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    Hi all,

    Just wanted to get your thoughts and learn more about NA's electrical system.

    In Europe it seems like they are able to leverage existing infrastructure to put charging stations virtually almost everywhere. Example articles below:

    London is installing electric car charging stations inside lamp posts for street charging

    Germany is getting 12,000 new electric car charging stations by converting distribution boxes

    Now for the US, it doesn't appear to be as easy (though still possible). One thing Europe has going for them is that everything is virtually 230V/400Y, which means they can have A/C charging and DC charging with no issues. (Hence why you see A/C and D/C charging in a single station a lot).

    On the other hand, the US generally has:
    120/240 split voltage
    120V/208Y
    277V/480Y

    277V is outside the range for A/C charging. (Tesla did support it before with the HPWC, but from what I read this was too close to the upper range supported by the car), so depending on the lightning system installed you can't just stick in a plug without a step down transformer, driving up cost.

    This doesn't matter for D/C charging but it costs a lot more to put in a DC charging box.

    So what I'm wondering is:
    • When I see streetlamps and/or parking lot lights, how often are they 277 or higher vs a lower voltage?
    • Was there a reason why Europe went with a standard where you generally need to bring a charging cable? One advantage with that is you can hide a charge point if you want to and not have a cable always being shown, and the cable locks too.
    • Long term do you see any changes to the charging standard or a new tech (cheap transformer?) to make it easier to install EV charging almost anywhere? I honestly don't see us being able to add chargepoints to street lamps.

    I kind of wish that Tesla had increased the voltage range supported, but I guess it wasn't worth the increased cost.
     
  2. arg

    arg Supporting Member

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    One of the reasons was the need to support more than one connector at the car end. Significant numbers of cars had appeared using the same connector as in the USA (we call it "type1" and you call it "J1772"), but this was not really satisfactory for Europe as it only supports single phase AC, and in many parts of Europe domestic power is three-phase (and at a sufficiently low current that charging a car off just one phase would be very limiting - 16A or less).

    So we have the type2 connector that can be used with either single phase or three-phase, the type2 connector universally used on public chargepoints, and cars gradually migrating from type1 to type2.

    There's also the issue of socketed chargepoints needing less maintenance (due to wear and tear or vandalism of the trailing power cord), but I don't think this was what motivated the decision, and I guess we will tell in due course from US vs European experience whether the inconvenience of carrying the cables is worth it for better chargepoint reliability.
     
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  3. yuhong

    yuhong Member

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    This is also a problem in Canada, where 347/600V is standard but most DCFC chargers are designed for 277/480V. Granted, I don't know which kind of circuit KSI was installing their chargers on, but remember that 50kW is not the end of road for charging.
     
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  4. yuhong

    yuhong Member

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    And I believe that Tesla did eventually increase the range of voltages supported in newer Model S/X.
     
  5. yuhong

    yuhong Member

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    And yes I believe that 277/480V was common in the US especially before the switch to LED lighting.
     
  6. arg

    arg Supporting Member

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    I think it's more the other way around. The pre-facelift cars could theoretically support 277V, since the same charger modules are used in the Supercharger cabinets (the original 120kW superchargers used the modules from the 2012 USA-spec Model S; the later 145kW output superchargers used the updated charger modules designed for the EU-spec Model S).

    The original HPWC was rated 240V only. The 2nd generation HPWC ("Wall connector") when first released did support 277V - it was listed as an option in revision A of the 2nd gen WC installation manual, but when I checked the current edition of the installation manual (revision C), the references to 277V have been removed.

    I am not sure of the voltage capability of the newer charger modules in facelift cars; certainly within the range of normal voltages they appear to be power limited where the older ones were voltage limited (ie. old modules as the voltage increased so did the output power, hence the use in Superchargers at higher power on 277V, while the new ones have a hard power limit and will draw less current as the voltage increases above nominal to maintain the same power).
     
  7. yuhong

    yuhong Member

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    What I was referring to is that the older ones can do up to 285V, and the newer ones can do up to 305V I believe.
     
  8. quantumslip

    quantumslip Member

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    I had to dig around but I finally found an image that seems to indicate the specs on the newer charging modules (though it only says 300V RMS as the upper range). The newer pictures don't have that sticker with voltage input but this one does: Autobahn Parts - Electrical, Tesla Model S (2012-2015) OEM GEN 2 Sealed Charger Part# 1014963-00-C, 1014963-00-C

    Still that should be enough and does cover the expected range for power delivery of 277V (see https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf)

    Based on what I see then Tesla could bring back 277V 1p charging support officially. The issue is the older cars with the older chargers do not have proper support to account for the voltage range. (And of course I don't know if the chargers on the plug side themselves have issues with 277V). Short of retrofitting older cars with newer charging modules, I don't know how you could deploy 277V charging. Hopefully they could revisit this in the future and make this work somehow.
     
  9. arg

    arg Supporting Member

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    But that's the Gen2 charger (Model S since EU deliveries, Supercharger generation with 145kW output).

    It is not the new charger (introduced on Model X, now on facelift S too). That one is not used in Superchargers and I have not seen any data on its specification.

    The oldest cars (2012 USA) also have charger modules which were used in the contemporary Superchargers (120kW output) at 277V.

    It's the new cars we don't have information about.
     
  10. quantumslip

    quantumslip Member

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    Oh, I thought they were the same (at least the 48A ones) since they had the same input current values. But I guess they are different (esp the 72A version). Hopefully they have the same input voltage ranges?

    Side note: 145kW /2 ~=72kW, the same amount of power per Urban charger.

    The main difference was that the range (at least on the label) maxed out at 277V vs 300V on Gen 2.
     
  11. quantumslip

    quantumslip Member

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    Oh yea, one more thing I noticed, even on the newest HPWC install guide they do still refer to voltages > 240V in the DIP switch setting, so that seems to imply the me the HPWC itself still could do 277V unofficially.
     
  12. arg

    arg Supporting Member

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    Plainly the hardware is the same, and it worked in at least a fair number of situations or they'd never have put 277V in the initial set of instructions. We don't know what caused them to take it away - maybe it's one particular group of cars, or maybe it's even non-Tesla cars, that with people making up Tesla->J1772 connector adapters, Tesla are afraid of the implications of people blowing up other manufacturers' EVs. Or maybe it all works fine technically, but there's some regulatory requirement it doesn't quite meet at 277V.

    Yes, but the standard gen2 superchargers have been 145kW for years now. Everything points to the urban superchargers simply being more lightweight hardware for the stalls, with the cabinets being unchanged from 'rural' superchargers, just with a software change to force the split 50:50 rather than the variable split normally supported.
     
  13. Fiver

    Fiver Active Member

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    To merge two threads here....

    The current HPWC can still do 277v, it's just not officially supported by Tesla.

    Apparently Model 3 will not charge from a HPWC that is set to 277v.

    Guessing Model 3 is the reason they dropped official support for 277v HPWC, it would be confusing for drivers if some HPWC worked for their cars but others didn't. Most of the time they have no idea what the voltage is, they just plug in and it works... except when it doesn't. (208v/240v yes but 277v no, made more confusing by the fact most S & X can charge from 277v just fine.)
     
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  14. cellogig

    cellogig Model X..Model 3

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    This is what happened to me with Tesla support on the phone. This was month 1/2 ago and there has been no resolve. No one explained it to me until today why it was happening. Now I have to find the person to resolve it. You know the finger pointing time.

    I am very concern for other owners not aware of this issue. As I stated on the other thread , the site I attempted to charge at is a Tesla destination charger listed at their website.

    Hopefully on some secondary charging apps that people will write if it is not model 3 friendly.

    Below where did you get this information?

    The current HPWC can still do 277v, it's just not officially supported by Tesla.
     
  15. Fiver

    Fiver Active Member

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    The hardware hasn't changed since they released the second version of the HPWC, the only thing that's changed is the removal of all mentions of 277v support from the installation manual. (And the release of the Model 3, that doesn't take 277v)
     
  16. cellogig

    cellogig Model X..Model 3

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    So the electrician installing the second version knows only to setup the charging station to 240v or 208v?

    Also could there be a possible dip switch to dial down the voltage coming through the line or they will have to use a transformer?
     
  17. Fiver

    Fiver Active Member

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    Gosh I wish it was that easy :cool:. You have to use a transformer to dial down the voltage, as mentioned before, adds cost and complexity. It's too bad they didn't allow 277v charging on the 3, it's a nice speed boost of typical 208v commercial power.
     
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  18. cellogig

    cellogig Model X..Model 3

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    Thank you for the info!!
     
  19. yuhong

    yuhong Member

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    Trivia: Tritium's DCFC chargers (licensed to ChargePoint) is quite interesting in that it can either use 277/480V three-phase (without neutral) for charging power and 120V for control, or a 230/400V three-phase with the neutral being used for 230V control.
     
  20. nwdiver

    nwdiver Well-Known Member

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    How would that even work? There's 277v HPWC out there. What would happen if a 3 connected to one? It's not like the owner would know it's 277v....
     

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