Hybrid Vehicle Design Trends & Implications for Capacitors

Advances in automotive technology have been amazing over recent decades. Electronics has entered the scene as an enabler of improved mileage and performance. Yet, as impressive as electronics integration has been, the future holds even greater promise.

Electronics use has a dual impact upon auto performance. The first is the ability to optimize performance in real time through precision control technology. It also offers the ability to help reduce weight considerably, thereby yielding significant miles per gallon (MPG) improvement. Though the exact MPG increase depends on the weight of the car, every 100 pounds of weight reduction will improve fuel efficiency approximately 2 percent.

Examples of common weight reductions resulting from electronics are multiplexed communication buses and electric power-assist steering, which also reduces belt loading on the engine, thereby offering additional MPG improvements.

Hybrid cars will demand a wide variety of electronic improvements, which will entail new requirements for capacitors. The extent to which capacitors will be challenged will correspond to the hybrid car type — e.g., plug-in hybrid, mild hybrid, etc.

Power capacitors will be required for decoupling the power source and the drive train. Although electrolytics are commonly used now, as voltages increase and failure mode considerations expand, film capacitors appear to be winning favor on next-generation higher voltage inverters and converters.

Supercapacitors are commonly used in regenerative braking schemes, but design trends have already pushed supercapacitors to higher power density for larger energy recovery schemes. A novel design trend is calling for smaller case size, smaller values with dramatically lower ESRs for use in “point of load” circuits within vehicles.

Safety capacitors are being required throughout hybrid vehicles on high voltage lines in large numbers. Safety capacitors typically utilize ceramic or film technology. High voltage snubber capacitors are being required to work at temperatures above 125°C. There is a growing need for high-voltage, high-temperature capacitors to evolve quickly to protect expensive IGBTs and other sensitive electronic components.

The typical trends of higher C/V and reliability will continue for automotive-grade small signal capacitors. Form factor will need to change as well, from traditional case sizes to filter configurations. Because of concerns over hybrid vehicle EMI emissions and susceptibility, automotive-grade versions of miniature SMT EMI filters have already been introduced to designers.

This is just a snapshot of major capacitive trends within the hybrid vehicle. External trends of charging, monitoring, and control all have their own set of significant requirements on other capacitor types.

9 comments on “Hybrid Vehicle Design Trends & Implications for Capacitors

  1. Barbara Jorgensen
    October 6, 2010

    Hi Ron,

    Automotive companies are notoriously tough on their suppliers–usually for good reason, when driver safety is involved. Can you give our colleagues some pointers on how to get the attention of an automotive supplier if you are not already in the door?

  2. Steve Saunders
    October 6, 2010

    who are the leading providers of this tech? Is it dominated by megsa companies aor are smaller outfits getting a look in?

  3. bolaji ojo
    October 6, 2010

    There are several major manufacturers in the capacitor market, including companies like AVX, Kyocera, Kemet and Vishay. Over the last 10 or more years smaller manufacturers have emerged in Asia that have taken market share in the lower end of the sector forcing companies like AVX and Vishay to target higher-end and cutting-edge products. This is where they are making a difference and hence their focus on technology differentiation in consumer segments like automotive and wireless communications. As Ron Demcko points out, companies that are able to offer technologically advanced products will get the opportunity to have their components designed into hybrid cars, high-end vehicles and military equipment.

  4. Steve Saunders
    October 6, 2010

    thanks Bolaji – very interesting

  5. SP
    October 6, 2010

    I am asking this out of curiosity, is there any hybrid vehicle already in market that uses these capacitors.

  6. Paumanok Publications, Inc.
    October 7, 2010

    Hey Ron; I was showing some of our friends in Greenville this new dielectric material I came across at the TED Conference.  What do you think the value of a trully biodegradable dielectric material is?  One that when put in a landfill would actually benefit the environment and help things grow.  What I trully had to grasp was that the production process to make the dielectric is about 50% of the current cost of goods sold for OPP or large Can PET capacitors; and what really got me going was that it was moldable into abstract shapes (like the Greatbatch wet tantalums).  Anyway, if there's a scientist in the USA that can understand something like this its you.  P.S I was at a meeting in DC a few months back and the current powers that be were trying to evoke innovation as the way out of economic woe and a second dip.  He said- “Can American Innovate its way out of this.”  I liked that.

  7. bolaji ojo
    October 8, 2010

    Paumanok knows his onions. He also knows a thing or two about innovation as a catalyst for growth too. Ron, can you help educate the rest of us on the questions Paumanok raised? What are the major differences between all these applications as the industry tries to find new ways to upgrade products for use in hybrid vehicles? The reason hybrid auto emerged was due to the need to reduce carbon footprint and the entire bill of materials that goes into a vehicle therefore has to contribute to the attainment of that goal, including capacitors made by your company.

    If there are costs savings from making biodegradable dielectric components as Paumanok says the industry should be exploring it. The company that finds a way to do this benefits from lower costs, which can be passed onto customers and used as leverage for securing supply contracts, and also gets to boast it is contributing to “Saving the Earth.” Are these types of components heading to market anytime soon? If not, what kind of research is being done and how soon will we see this type of products that can go into a landfill without negatively impacting its environment?

  8. Hawk
    October 9, 2010

    Will Mr. Demcko respond? I find Paumanok's questions interesting even though it is a bit technical. The last bit about whether or not America can innovate its way out of a recession is quite important. The challenge is that as America is innovating so are other parts of the world. Will we all innovate ourselves into first place? I don't think this is going to happen in all countries and for all economy sectors. I would like to know, though, if the hybrid capacitor innovations Mr. Demcko identified are all American or if other companies based elsewhere are similarly involved. The consumer may not care about where the product was developed, though. If it works well and is better and cheaper than the alternative, I don't care who designed or produced it.

  9. Ashu001
    October 10, 2010


    Its good to see increased & more aggressive adoption of Capacitors in Hybrids,but is it possible for Capacitor manufacturers to reduce size of the Devices themselves(because the lighter they are the more fuel-efficent the car will be??)

    I personally know a lot of Battery manufacturers are experimenting with different metals to see which works best(durability and efficency point of view).If we can get super lightweight,Cheap and long-lasting Batteries for Hybrids,Hybrids will see an increase in sales like theres no tommorow.

    And Californians won't be upset about paying $10/Gallon at the pump either…

    Its a stupid idea(raising Gasoline taxes to pay for public transportation and paying Bloated Union salaries,but if alternatives to Gas driven automobiles exist,a lot of Californians might go with it)…



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