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Doesn't regen make AC power? How can my car handle 60 kilowatts of juice?

Discussion in 'Model S: Battery & Charging' started by SuperCoug, Mar 14, 2013.

  1. SuperCoug

    SuperCoug Model S Res #7734

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    My 60 kWh Model S is equipped with a single 10,000 watt AC on board charger which (as I understand it) converts AC power from the plug and to DC power to store in the battery.

    The Model S has an AC motor so doesn't it produce AC electricity during regen braking? If so, how can my car possibly handle 60,000 watts of AC power during full regen? If it can handle that much AC power from regen why can't it handle that much shore power?

    I'm sorry if this is a dumb question or has been explicitly address elsewhere.
     
  2. Stoneymonster

    Stoneymonster Active Member

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    I'm guessing it goes through the main inverter between the motor and the battery somehow. Can inverters be reversible?
     
  3. strider

    strider Active Member

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    Yes, the same way it takes DC from the batteries and converts it into AC for the motor, just in reverse. In the earliest Roadsters they actually used this to charge the car but it had some problems so they went to a dedicated charging circuit.
     
  4. FredTMC

    FredTMC Model S VIN #4925

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    omg, I thought about this exact design issue today! Classic. Yep I bet the inverter is utilized.
     
  5. Johan

    Johan Took a TSLA bear test. Came back negative.

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    The Renault Zoe is said to be doing this - using the drive inverter for plugged in charging, which gives it a cheap 43kW 3-phase charger called "Chameleon charger". There have been many disussions as to why Tesla went the route of s separate AC charging system but that's also how most (all) other EV's except the Zoe does it.
     
  6. Al Sherman

    Al Sherman It's about THIS car.

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    So, inverters ARE reversible? I did not know this. We used to call AC to DC a TR (transformer rectifier). If it only did AC to DC would it still be an inverter?
     
  7. strider

    strider Active Member

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    A EE boffin/nerd would have to chime in on what it's called. I agree that historically DC->AC is an inverter and AC->DC is a rectifier but Tesla's (and every other EV that I know of) has an "inverter" and it can work in both directions. There's a little bit of detail here:
    Power inverter - Wikipedia, the free encyclopedia
     
  8. gavine

    gavine Petrol Head turned EV Enthusiast

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    And 2 years later, I though of this question and found this thread via search. Glad I'm not the only geek who though about this.
     
  9. Kalud

    Kalud Member

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    The on-board charger(s) are not used in this process. They are 100% idle while driving.

    The inverter is used both ways to re-gen power.
     
  10. Cosmacelf

    Cosmacelf Active Member

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    Does anyone know/remember what the problem was with the roadster combo inverter/charger to charge the car? Why did they switch to a dedicated charger for the Model S?
     
  11. qwk

    qwk Model S P2681

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    Royalty fees to AC Propulsion.
     
  12. SabrToothSqrl

    SabrToothSqrl Active Member

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    When you invert an inverter, do you just get a verter?
     
  13. NielsHP

    NielsHP Member

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  14. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    No, they're reverberate.
     

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