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Transportation Hardware

New Semiconductor Could Improve Vehicle Fuel Economy By 10 Percent 119

Posted by Soulskill
from the efficiency-plus-plus dept.
cartechboy writes: "Automakers are scrambling to increase vehicle fuel economy every year as regulations increase, so when an automaker finds a way to possibly increase fuel economy by 10 percent with one new part, that gets some attention. Today that automaker is Toyota, and the part is a new semiconductor. Toyota's power control units (PCU) in its hybrids use semiconductors to govern the flow of electricity between the battery and the electric motor. Unfortunately, they're also an electrically restrictive component. Toyota says the PCU accounts for a quarter of the total electrical power losses in a hybrid drive system, and semiconductors alone make up a full fifth of the total. Reduce electrical losses through a semiconductor, and you can make your hybrid system (and therefore your car) more efficient. Toyota has done this, in theory at least, using a new silicon carbide material for its semiconductors, rather than a standard silicon unit. The future could be shaped by individual parts, and this new semiconductor tech is one piece of that puzzle."
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New Semiconductor Could Improve Vehicle Fuel Economy By 10 Percent

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  • by Anonymous Coward

    Are these SiCFETS with lower R(on), or improved SiC IGBTs, or what?
    I wouldn't think so, because silicon carbide transistors isn't brand spanking new, unless you count a few years old as new.

    • by jonsmirl (114798) on Friday May 23, 2014 @04:19PM (#47078219) Homepage

      Amazingly content free press release. No clue what these devices are. This is just fluff reporting with no details.

    • SiC FETS and IGBTs have been around for a while from Cree and other vendors.

      I'm really surprised that they can get a 10% improvement in overall efficiency from this. I would have thought that the switching electronics was already in the 90% efficiency range, and SiC isn't going to reduce the losses to 0.

      The article says that the switchers are 20% of the LOSSES, not 20% of the power. I hope they losses are not 50% (!!!!!)

      Maybe they meant that the switching LOSSES would be reduced by 10% - that I believe. Th

      • by BronsCon (927697)
        I think the article (and by transition, the summary) inverted the terminology, in which case, a 10% reduction in losses is a 10% of 10%, or a 1% improvement in efficiency.
  • My favorite local semiconductor manufacturer produces SiC wafers (and power components), and has seen a nice stock-price bump over the last day or two. Wonder if it's related to this news?

  • "The future could be shaped by individual parts, and this new semiconductor tech is one piece of that puzzle.""

    Apart for the fact that this new semiconductor tech isn't an individual part, then sure.

  • You know what else increases fuel economy? Not driving everywhere. OK, I understand it doesn't really increase the fuel economy, but I find it odd that people drive absolutely everywhere. Just about everyone I know who owns a car refuses to walk or take the bus, even if that would actually be an easier/cheaper option.
    • Also driving slower, not driving full throttle and hard braking to a stop light/sign, etc.

      I used to have an 2008 MkV Jetta with the 2.5L gasoline engine. The government said I should be getting 21/29mpg city/highway. My best was 46 mpg driving from Sacramento to San Diego. Now I have a Prius V, and I get better gas mileage than that without even trying.

      • Also driving slower, not driving full throttle and hard braking to a stop light/sign, etc.

        Or you could just buy a diesel.

        I used to have an 2008 MkV Jetta with the 2.5L gasoline engine. The government said I should be getting 21/29mpg city/highway. My best was 46 mpg driving from Sacramento to San Diego. Now I have a Prius V, and I get better gas mileage than that without even trying.

        I bought my wife a 2012 Jetta TDI, and she regularly gets 45-50 MPG, even with her lead foot. But even our old gas Jetta was getting somewhere in the range of 25-35.

        • The problem with diesel cars in the USA is that they're more expensive than current hybrids (particularly the Prius) and diesel fuel is on average more expensive at the pump than 87 octane gasoline.

          • The problem with diesel cars in the USA is that they're more expensive than current hybrids (particularly the Prius)

            The hell they are:

            2014 Jetta TDI Value Edition: [autoblog.com] $21,295

            2014 Beetle TDI: [vw.com] $24,595

            2014 Chevy Cruze Diesel (no options): [chevrolet.com] $24,310

            2014 Prius Base Model: [google.com] $24,200

            Seems to be just about the same to me, save the Jetta; mine was a bit more (~$28,000), but that's because I sprung for every option except satnav. Seems the real problem is lack of options, unless you're a VW or Chevy fan.

            diesel fuel is on average more expensive at the pump than 87 octane gasoline.

            Yea, but you get almost-if-not-more-than twice the miles out of the same amount of fuel, so it ends up being a net win. I will concede t

            • by geekoid (135745)

              With the benefit of more noise, carcinogens, soot and NOx.

              • Yea, because the processes of mining rare-earth minerals and converting them into batteries is so clean and environmentally friendly.

          • On the other hand, you can get diesel for SUVs or trucks, so if you need one of those diesel is often your most fuel-efficient option.

            • by dbIII (701233)

              On the other hand, you can get diesel for SUVs or trucks

              Hence the reaction of most of the rest of the world when confronted by a petrol driven POS offroad vehicle from the USA.
              "That's not a real offroad vehicle. Even little old apartment dwelling Japanese men wearing white gloves build far better offroad vehicles than that piece of shit built by a company run by drunken rednecks."

              • by geekoid (135745)

                Interesting. My friends in former eastern block countries love american off road vehicles as then seem to be the only ones the last in ares where the roads aren't good.

                • The ones that make it for export are things like Jeeps and not the wide variety of piece of shit fake offroad vehicles designed to make their buyers feel tough, so long as they never dare to get dirt on it.
                  Jeeps can come with diesel. They are built for a practical and not cosmetic purpose.

                  I thought the POS label would be enough for people to work it out that I am describing the utter lemons and not every thing on the road.
          • Diesel cars have much better mileage, more torque and diesel engines normally last longer than regular cars.

            but I agree hybrids are better for city use.

          • by dbIII (701233)

            and diesel fuel is on average more expensive

            Which appears to be an odd "only in America" thing. The stuff is cheaper to make at the refinery.

      • by hurfy (735314)

        lol, I am always amazed how many people pass me as we approach a red light. Is buying brake pads a fun experience I have been missing out on?

    • You know what else increases fuel economy? Not driving everywhere.

      As driving gets better and cheaper, people drive more. It's not surprising - driving has benefits and gives people pleasure, either directly or indirectly. If it costs $2 to drive to the beach, I go in a heartbeat. If it costs $200 I stay home.

      Improving the human condition is great, but just don't expect improved MPG to do much for overall fuel consumption outside of commuting (where group options may be better anyway).

    • by Kardos (1348077)

      Buses take longer. There's only so much time per day, if you spend it waiting for buses, you get less done.

      • by geekoid (135745)

        Buss are the least environmentally friendly thing you can take.
        By a long shot.
        If everyone on a bus instead drove a car that got greater then 19MPG, less gas would be used overall and a hell of a lot less emissions.
        Buss where designed so the poor people can get to work.
        That was their purpose. No being environmentally friendly, or quicker, or convenient.

      • by AmiMoJo (196126) *

        Only because public transport sucks where you live. In Tokyo it is often faster than taking your own car. Buses and trains come every few minutes, and the time you spend waiting is more than made up for by avoid the traffic jams, parking and filling your car up every now and then.

        You get more done because the time you spend travelling is not wasted controlling a car. You can browse the net on your phone, post to Slashdot and answer emails, play games or just relax.

    • by neminem (561346)

      You have to factor in time, as well. I *do* walk and take public transportation, when the combination of effort, time and money one of those options costs seems nicer than driving - for instance, driving into downtown LA, is a lot faster than taking the light rail if there isn't traffic, but there's usually traffic, plus then when you get there you have the immense fun of finding parking. So it's often (not always) nicer taking the train, so I do. On the other hand, I tried taking the bus once across town.

    • by evilviper (135110)

      Just about everyone I know who owns a car refuses to walk or take the bus, even if that would actually be an easier/cheaper option.

      I just recently checked bus prices, and I got to the destination several times faster driving, on $20 in gasoline, versus a $40 bus ticket.

      Prices serve as a very good proxy for efficiency... Based on prices, I do not believe that buses are more efficient for short to medium trips in the US.

      • by evilviper (135110)

        I forgot a significant detail... That's $20 in fuel for the ROUND TRIP, while the $40 ticket price was one-way, and not just took longer, but required substantial travel by foot to reach the destination from the nearest station.

        • by dbIII (701233)
          Meanwhile in China alone there are millions of counter examples a day that laugh at your outlier. Still sucks to be hit for that much for a ticket though.
          • by evilviper (135110)

            My example isn't an outliers, it's typical pricing. And pricing in China has no relevance at all. In the US, bus travel is incredibly inefficient.

            • Globally the consequence of extreme price gouging you are seeing locally is an exception instead of the rule. Using it to suggest that public transport is always a bad idea is either stupid or dishonest.
              • by evilviper (135110)

                Globally the consequence of extreme price gouging you are seeing locally is an exception instead of the rule.

                On the contrary, public transit is subsidized. The opposite of gouging. To implicate gouging, you need evidence, and you've provided NONE.

                Using it to suggest that public transport is always a bad idea is either stupid or dishonest.

                You're the idiot that chose to expand this topic out to the other parts of the world. This was clearly about the US, until you went nuts and started talking about China,

                • by dbIII (701233)

                  You're the idiot that chose to expand this topic out to the other parts of the world

                  So why is that being an idiot? Please explain why it is not a relevant example if somebody other than your local bus company can get their shit together?

                  • by evilviper (135110)

                    Please explain why it is not a relevant example if somebody other than your local bus company can get their shit together?

                    But you didn't point to just some other bus company... You went straight to THE OTHER SIDE OF THE PLANET, where the economics are completely, totally, and utterly different.

                    Why isn't this simple and obvious fact, painfully obvious to you?

                    • Why isn't this simple and obvious fact, painfully obvious to you?

                      Because this was never about the USA in the first place but about fuel economy and public transport costs. You shifted that goalpost yourself for some reason that is unclear and IMHO totally irrelevant to the discussion.
                      Besides, while it may be true NOW in the US where your bus company has a local government mandated monopoly it was not true in the past when there were multiple purely commercial bus companies.

                    • by dbIII (701233)
                      Fair enough, I see the confusion comes from a simple disagreement:

                      Based on prices, I do not believe that buses are more efficient for short to medium trips in the US.

                      I strongly dispute that prices in this case are a measure of efficiency. In a monopoly situation there are stronger drivers of price. That's why I think considering the situation globally is the only fair comparison if you want efficiency to be a factor. Doing so means the utterly ridiculous $40 price gouge you describe above would be an out

  • All that verbiage to say nothing except "Toyota" and SiC.
  • Old News (Score:2, Informative)

    by Anonymous Coward

    How is this news? SiC semiconductors including Schottky diodes, JFETs and MOSFETs have been commercially available since 2008. My first design to use SiC JFETs and diodes was in solar power inverter developed back in 2009 (and yes the RDSon and revers recovery times are indeed exceptional). Stay tuned for: "Toyota discovers wonder metal by adding carbon to iron"

    • How is this news? SiC semiconductors including Schottky diodes, JFETs and MOSFETs have been commercially available since 2008. My first design to use SiC JFETs and diodes was in solar power inverter developed back in 2009 (and yes the RDSon and revers recovery times are indeed exceptional).

      "Commercially available with the specs you need for a solar power inverter" does not necessarily equate to "commercially available with the specs Toyota needs".

  • It's not as big a deal as they're making it out to be, really. It's got a lower 'on' resistance. Similar reductions in power lost to waste heat could be accomplished by using more MOSFETs in parallel. Don't get me wrong, it's a useful development, but it's not earth-shaking news either.
    • by viperidaenz (2515578) on Friday May 23, 2014 @04:55PM (#47078597)

      It has a faster recovery time too. More MOSFET's won't change that.
      Faster recovery time means they can run at a higher frequency and use smaller inductors to convert the voltage. Lower inductance means less copper, less resistance. So not only is there less loss in the transistor, there is less loss in other components.
      If you keep adding more MOSFET's, you need to keep increasing the drive current or they'll switch slower.
      While a MOSFET is switching, the resistance can be quite high. Even if faster silicon carbide transistors had the same Rds, there would be lower losses during switching.

    • by NoKaOi (1415755)

      Coming up with a new MOSFET with a lower on resistance is a big deal, particularly if it has broader uses outside of automobiles (the article doesn't really have much in the way of details). Allowing anything with MOSFET to be 10% more efficient and with less heat, yeah, that's a big deal.

      Now, the article mentions silicon carbide. Cree already makes silicon carbide MOSFETs (although they're expensive), so as far as I can tell (please, somebody correct me if I'm missing something), either this isn't news a

      • by kheldan (1460303)
        That's kind of my point, actually, it's not really news. These sorts of developments happen all the time and really nobody but engineers who need to use them notice. This smacks more of Toyota trying to generate some positive press for themselves than anything else.
  • That's why CREE are the only ones who make white LED's on silicon carbide.

    • Actually, Cree does it because they vend the 4H SiC used in these things.
      Everyone else uses either AlN or BN or Diamond film
    • A 150-year old observation about markets and business production does not apply to individuals spending money to reduce consumption. Sure, a few people who overspend to get a more fuel-efficient car will maintain their gasoline budget and take extra trips in it, but far more will take the money saved on fuel and spend it on other things. Sure, those things have their own energy costs, but a fancy Apple gizmo has far less embodied energy than the gasoline the owner saved. Besides, those wacky environmentalis

  • Battery efficiency is not the same as fuel efficiency.

  • Found a better site (Score:4, Informative)

    by AutodidactLabrat (3506801) on Friday May 23, 2014 @07:18PM (#47079825)
    Looks like Toyota has produced the pinch-channel Class I V transistor in SiC with no minimum offset / gain.
    Seriously, holy grail for current steering.
    Can't find the vendor of the raw SiC so no idea about Delta-V / Delta-I limits but looks very good
    10% net reduction in loss.

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