Mitsubishi shrinks EV engines

Posted by Aaron Colter, EarthTechling

Mitsubishi has announced a new electric motor that could shake up the green car industry in a good way.



The auto manufacturer recently released news of a prototype electric vehicle motor system that features a built-in silicon carbide inverter, making the system smaller and lighter than earlier versions and potentially improving vehicle energy efficiency.

Mitsubishi shrinks EV enginesThe car company says its latest innovation will give automakers the ability to develop electric cars with greater passenger space as the new built-in inverter (the electrical device which converts direct current to the more manageable alternating current) is designed at only half the dimensions of their current electric motor system, which comprises separate motors and the inverters that drive those motors.

The new inverter is also cylinder-shaped and equal in diameter to the motor itself, enabling it to be connected coaxially within a chassis.

Perhaps the most important component of the new electric motor system is Mitsubishi's decision to switch from using silicon chips in the powering devices for inverter switching, to using silicon carbide.

The subtle difference in the chemical component is extremely important, as silicon carbide has a breakdown electric field tens times greater than silicon alone, allowing for thinner chips. The silicon carbide chips also have a 50% reduction in loss compared to the older chip model.

Mitsubishi has also improved its permanent, neodymium magnent motor, and was able to reduce the size while seeing magnetic efficiency increase and a 5 percent power output boost.

Electric vehicles and hybrids are in a somewhat interesting position in the American market at the moment. While February saw an increase in green car sales, Chevrolet has temporarily suspended production of its much-talked-about Volt, saying the vehicle has become a "political punching bag."



The heated debate surrounding government assistance for the automobile industry, already a hot-button issue, has seemingly increased during this election year. EarthTechling's Susan Kraemer made a compelling argument that the Obama administration's $5 billion investment to reduce the cost of batteries in electric cars by half by 2015 will make electric vehicles more affordable for everyone.

Still, if Mitsubishi wants its i-MiEV, which was only recently released into the U.S. market, to start to reach sales levels of the Nissan Leaf, then it will need to appeal to consumers outside the traditional base of early green-tech adopters who are comfortable paying more for a vehicle that's often smaller and less powerful than gasoline models. Plus, the company will have to compete with Ford's latest electric Focus.

By creating a new motor system that is smaller is size and weight, Mitsubishi should, someday, be able to create a car that is a bit larger and more powerful than the i-MiEV, which is admittedly price competitive compared to other electric vehicles, but ultimately still too miniature for many drivers' tastes.

Mitsubishi says it will commercialize the new electric motor system after finalizing cooling technology, downsizing and energy efficiency. If the new technology is as beneficial as the company claims, the advancement could be a boon to manufacturers everywhere, who can mimic the designs to make their own products better.

* Aaron Colter, EarthTechling