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Toyota testing semiconductor technology - SiC

Discussion in 'Prius, Hybrid, EV and Alt-Fuel News' started by telmo744, Jan 29, 2015.

  1. cyclopathic

    cyclopathic Senior Member

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    Not sure if this would be a good approximation. I ran Torque on "C" and for the most part ICE RPMs stay under 2,000. Can check on Gen3 but it likely to be similar. With respect to torque split it is likely to be quoted either at specific RPM or some "effective" RPM - average over test cycle(?)
     
  2. usbseawolf2000

    usbseawolf2000 HSD PhD

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    Torque split is constant. Power split varies depending on the MG1 rev and torque.
     
  3. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    the 5252 is an artifact of the units chosen: For any engine* at 5252 RPM Imperial HP and Torque in Foot Pounds are equal.

    *any engine that can be operated at 5252 RPMs, below that Torque is always greater, above that HP is always greater.
     
  4. ChapmanF

    ChapmanF Senior Member

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    No fair - you don't get to talk about the single RPM out of the engine but in the same breath talk about the two different torques it delivers to the sun gear and ring gear. Their rpms are in general different too.

    The torque felt at the sun gear (= MG1) from the planet carrier is always .28 ✕ the engine's output torque. The torque felt at the ring gear (= MG2) from the planet carrier is always .72 ✕ the engine's output torque. The power in each case is always the torque felt at thing ✕ the rpm of thing (✕ your favorite units constant).

    For example, the rpm of the ring gear is always fully determined by the vehicle speed. If you are doing a force-charge with your foot on the brake, the ring gear still feels .72 of the ICE torque as always, but it's not moving so no power is following that path, and all of the power being developed by the ICE is following the electrical path.

    At the other extreme, in heretical mode, the torque at the sun from the planet carrier is still the same old .28 of ICE torque as always, but the RPM of the sun gear has changed sign, changing the sign of their product: the power flow on the electrical path is backward (and there is more power following the mechanical path, forward, from planet carrier to ring gear, than the ICE is producing!).

    -Chap
     
  5. cyclopathic

    cyclopathic Senior Member

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    Yes 5252 constant is used to convert torque to HP, but this is not a question here.

    Where it gets tricky, which RPM? ICE redline is below 4,900, and electric is 10,000
    Torque output is not constant, at least for ICE, and voltage and load on MG1/MG2 varies.
    You cannot make assumptions it's split 72/28 across the board
     
  6. ChapmanF

    ChapmanF Senior Member

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    Right, for power. For torque you actually can, because the torque split is fully determined by the tooth counts of the gears, and it's 72 and 28 every day of the week. But power is the product of torque and rpm, and the relative rpms vary.

    -Chap
     
  7. austingreen

    austingreen Senior Member

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    Bob right but there are different RPM's so it should be shown

    HPice = Torque*RPMIce/5252
    At mg1 we get 28% of the Torque at the engine shaft
    HPmg1 = 28% *Torque x RPMmg1/5252
    HPoutput = 72%*Torque x RPMoutput / 5252 + HPmg2
    Now we have the electrical path. If there is no battery involved then
    HPmpg2 = HPmg1*efficiencymg1*efficiencymg2*efficiencyElectronics.

    Exactly. We shouldn't confuse torque with horsepower.
     
  8. hill

    hill High Fiber Member

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    havn't hybrid Formula 1 racers been using this for a while?
    .
     
  9. goldfinger

    goldfinger Active Member

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    Smaller more efficient inverters with compact wheel motors could make full series hybrid the way to go. How much does an entire drive train weigh? The generator could be located anywhere.