- Nov 21, 2010
The Next Frontiers In EV Technology
While the dimensions of many EV motors are smaller than internal combustion engines, what if there were a way to package even more power into a smaller bundle?
Protean, an engineering firm located in suburban Detroit, builds motors into the space surrounded by standard 18-inch automotive wheel. The finished assembly looks something like a bundt cake.
Two Protean motor assemblies, each producing 72 horsepower and 369 lb-ft of torque, provide nearly the same continuous torque as a diesel V8 truck engine. Importantly, peak power from a single Protean unit can be as high as 608 lb-ft, meaning a two-motor drive system would have over 1200 lb-ft of peak torque. That's power.
Craig Knight, president of Proteon, showed Translogic one of the hub motor's innovative engineering details: Each hub assembly actually contains multiple smaller electric motors that are just two inches in diameter. Each tiny but powerful motor can be individually controlled to produce maximum power (all motors on), maximum efficiency (some motors off), or maximum regenerative braking (motors working as generators).
"Our design offers great flexibility with the ability to scale the motors up or down in size," said Knight. Driving the company's four-motor, full-size Ford F-150 pickup proved that the design performs. The truck accelerated hard from a standstill, as if it still had a big V8 engine under the hood. When we actually looked under the hood, however, we saw a lot of empty space because the Proteon electronic control module isn't nearly as large as a conventional engine that used to fill the space.
Efficient and powerful hub motors would make design concepts like GM's 2002 Autonomy possible.
Some eight years ago, this concept popularized the idea of a "skateboard" vehicle platform on which any type of vehicle body could be fitted. Proteon motors would get designers one step closer to this EV reality. They also make it easier to convert an existing vehicle to electric drive because the motors occupy space that's already available.
When it comes to charging, we can soon expect to see so-called "fast-charge" systems. There are high-powered, 480-volt units that can potentially replenish an EV to 75-percent charge in just 15 minutes.
But there was an even more intriguing idea discussed: Inductive charging. Inductive charging makes physical plugs unnecessary. The charger and the vehicle just need to be in close proximity for the electrons to pass. GM's EV1 used a paddle-type inductive charger, as do many battery-powered shavers and toothbrushes. Inductive chargers are just starting to hit the market for cell phones and PDAs.
EV suppliers showed an artist's rendering of one concept featuring an inductive charge plate positioned on the surface of designated EV parking spaces. These charge plates would automatically connect to the EV and charge it passively while the vehicle was parked. The driver would not be required to physically plug anything in.
The extended possibilities for inductive charging are wide ranging. Imagine businesses such as fast food restaurants that offer drive-thru services. Their drive-thru lanes could offer inductive charging as a business incentive so that your car could get refueled along with its occupants. Other visionaries see inductive road surfaces powered by roadside solar arrays that charge EVs as they motor along or wait at traffic lights.