Monday, September 16, 2013

More Efficient Electric-Car Motor? Startup KLD Claims It Has One

Mass-market plug-in cars have only appeared in showrooms for three years, but startup KLD Energy Technologies thinks it's already time for a revolution.
KLD says its updated electric motor and battery pack, called OneDrive, can get the same range from a 3-kilowatt-hour battery pack as normal motors get from a 5-kWh pack.
How does the new motor do it? OneDrive uses the same 18650-sized lithium-ion cells (they're essentially laptop batteries) as a Tesla Model S, but its cells are a different type.
KLD says it uses power cells more similar to those used in hybrid cars, not the energy cells used in other plug-in car powertrains.
Power cells are designed with lower resistance, allowing them to discharge more quickly while generating less heat. This suits hybrids, which cycle their battery packs through a narrow charge range tens of thousands of times.
The startup also changed its motor design, using a permanent-magnet brushless motor with amorphous metal for the stator.
Unlike other metals, amorphous metals can't retain a magnetic field. That means they will stick to a magnet, but won't retain any residual magnetism when separated from it.
KLD says using this material in its motor's stator also reduces resistance, improving efficiency.
The motor also doesn't have a solid ring of electromagnets in its stator; instead, they're installed individually like slices of pie (seemingly somewhat similar to the "inside-out" wheel motors used by startup Protean.
This allows KLD to adjust the power output of a motor for a given application.
On the flip side, the company's rotor is larger than those used in most electric cars, which effectively gears the motor down for low rpm operation. This eliminates the need for an efficiency-sapping reduction gear, KLD says.
So far, KLD has only managed to put OneDrive into a small demonstration chassis, and into the Kombi City, a small utility vehicle made by Cenntro Motors.
If it's as revolutionary as KLD claims, major automakers are undoubtedly already taking a lot.