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Replacing the mosfets in a second gen inverter with sic mosfets?

Discussion in 'Gen 2 Prius Technical Discussion' started by terramir, Sep 15, 2019.

  1. terramir

    terramir Member

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    Just wondering SIC mosfets are far more efficent and well this would mean less losses to heat inside the inverter during regenerative Braking as well as during powering the electric motors, also, less heat might also be a fix for the 3rd gen failures.
    Just a thought I mean a few mosfets could be replaced, and could improve efficency and reduce heat produced by the inverter overall, while in there could replace some old caps as well I mean some of our inverters are like 16 years old now. ;- )
    What are you guy's and gal's thought on the subject. I think during the next 40% off sale at the junk yard this might be a purchase that I could look into. If it is worth exploring equivalent sic mosfets should be able to be sourced if I can cram through the data sheets for the original mosfets these inverters use.
    terramir
     
  2. qettyz

    qettyz Active Member

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    On this awesome video from WeberAuto John dissambles gen2 inverter 43:00 ->
     
  3. edthefox5

    edthefox5 Senior Member

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    The G2 inverter is a fantastic piece of engineering. There have been some failures on this site over the years but pretty rare as rare as trans failures.
    i Suspect most inverter failures in a G2 are from failed pumps that make it overheat.

    The inverter coolant loop is excellent and the inverter runs very cool so not much need to improve it. It runs about 90 degrees cooler than the engine,

    If your itching to improve the loop change the trans fluid and inverter coolant fluid. Check theinverter coolant behavior in the reservoir if the coolant does not look like it’s boiling in the reservoir I would change the pump. Should have very aggressive movement to it.

    While under there service the ac under dash e coil and then service the condenser in front of the rad.

    Dump the engine rad and fill it back up with coolant.

    Lots of things to do to make the car happier.
     
  4. terramir

    terramir Member

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    I know those things I was more concerned about efficency than heat really my loop is just fine.
    But SiC mosfets are a new tech that are actually being used in the newest hybrids making them more efficent
    terramir
     
  5. bisco

    bisco cookie crumbler

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    does the 2020 gen 4 have them? one thing we know for sure, toyota has had major inverter issues on gen 3.
     
  6. ChapmanF

    ChapmanF Senior Member

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    As I understand it, the switching elements in Toyota's inverters (the familiar generations, anyway) are insulated-gate bipolar transistors, not MOSFETs. Substituting them might be interesting, but might call for substantial changes in the driver circuitry too.

    Re: Gen 3, if I remember right from the root-cause analysis published at NHTSA, the "major issues" have often been solder joints that don't anneal nicely when driving conditions subject them to rapid heating followed by rapid cooling; the firmware updates were to avoid that scenario, but it was a further embarrassment that some of the recalled cars didn't really get all the intended updates, apparently because of a face-palm proofreading oversight in the step-by-step instructions given to the techs doing the recalls.
     
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  7. Orbpic

    Orbpic Junior Member

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    I know this an old post an i had to join up with Priuschat to through further light on ChapmanF comment, in America there was a lawsuit against Toyota (America) from a from a car dealer an sons against Toyota for selling such a vechile an permitting them to be sold when they where faulty ( Dangerous) infact they would just breakdown no matter where you were.. crossing a road, out on the highway or climbing a tree which i believe Toyota done once this got out! the hi voltage capacitors in the inverter where faulty from factory! they would overheat and this would disable the car ( being the Gen3 ) put people in danger due to road conditions the vechile would cause. yes good old NHTSA able bodies of the car industry assoicated bodies at hand so in the corporate side of things Toyota America took responsibility to cheaply correct such problems where they altered the software which gave less voltage to those capacitors which changed the emissions ( dont you love regulations ) there for those capacitors scenario oversight didnt rupture an explode or burnt out leaving owners of such a car abandoned smelly or firery vehicle. yes they have solder joint problems too and wiring like headlights but whom needs them right after this liability hit Australia there was a recall an surprisingly My 3rd Gen was called upon yo have dodgy software upgrade too that changed emissions control and changed the voltage going to those capacitors which in return charge the high voltage batteries thus the 12 volt one too but i wrote on the form that i hold Toyota ( Australia ) solely responsible if those capacitors fail where there liable for all costs involved for repair an onroad costs. crossed out there little small writing where you sign ;) Terramir i would be asking ChapmanF why would they putting bipolar transistors in afterall there only made for low voltage applications where the MOSFETs are made for high voltage applications and it isnt new technology but i find it S.I.C (K) that Toyota ( America, Australia ) would play around with people. if you have anyother questions Terramir try searching online for infomation ( un-sponcered ) so its not regulated through filters. back to the " Tree " if your wondering this means knowledge/able.

    So Mr. ChapmanF ( senior member ) why would Toyota (America, Australia) impose such a thing upon there people inviting them unknowingly of harm related to unsafe (Dangerous vehicles) that contain firstly bipolar transistors instead of MOSFETs which are designed for high voltage high temperatures unlike the bipolar transistors which are designed for low voltage applications and lets not forget about those capacitors as well you know the high voltage ones in the high voltage inverter under the bonnet of the Toyota Prius, let's also include those low voltage safety issues like the 12volt lights,instruments & modules as well as they too can cause fires. Do you ChapmanF find it S.I.C(K) that conutires trading on behalf of Toyota put such people in danger and now pass off old technology as new where if you know anything about electronics you dont use bipolar transistors in high voltage and high temperature applications unless it soley for testing purpose an i hope we the people werent for testing purposes testing out our integrity ?
     
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  8. 05PreeUs

    05PreeUs Senior Member

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    Great, another flat-earther....

    Here is an idea for you, Toyota makes the MOST RELIABLE Hybrids of ANY OEM and their inverters world-wide use the same switchgear, in the same model (and often more widely) and year (often more widely).

    In point of fact, the Toyota stuff is SOOOO good, many folks are using Gen3 Toyota inverter to drive TESLA motors as part of the growing DIY EV hobby.

    Lastly, this is the Gen2 forum, to which you claims are completely 100% not relevant.
     
  9. TMR-JWAP

    TMR-JWAP Senior Member

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    Yeah.....and in America there's 50 lawsuits a day because someone farted crooked....America is the lawsuit capitol of the universe and a huge percentage have no merit and are just people searching for a reason, any reason at all, to sue
     
  10. ChapmanF

    ChapmanF Senior Member

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    Looking for any part of this to which a serious answer can be given ... well, there's this:

    Insulated-gate bipolar transistor

    [​IMG]

    They're kind of popular for power switching.

    Here's a commercial DC-to-240-VAC power inverter that uses them too.
     
  11. TMR-JWAP

    TMR-JWAP Senior Member

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    This whole thing about IGBTs being for only low voltage is kind of funny. Our facility had about 60 Seimens water cooled variable frequency drives (with IGBTs) that used a 950 vdc bus and converted it to a 3 phase variable frequency AC waveform to drive 800, 1100 and 1300 hp electric motors. Worked great for 20 years, at which point we changed to air cooled VF drives. The only time we ever had problems with them is if they were near max power and lost cooling. That's when a plastic box 4" x 6" x 1.5" turned into a small hand grenade.
     
  12. ChapmanF

    ChapmanF Senior Member

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    Well, if you were a person who had never heard of IGBTs, and were just thinking 'bipolar' like some pokey NPNs and PNPs in your dad's old hi-fi, then you could end up posting something kind of like #7.

    For the greatest effect, it is best to sprinkle phrases like "where if you know anything about electronics" throughout such a post.