Hybrid Formula Race Showcases the Electric Drive

This week college students gathered at the New Hampshire Motor Speedway to race “formula” style, open-wheel, open-cockpit cars that they had built over past several months. The cars are hybrids–gas or diesel powered and boosted by jolts of electricity from ultracapacitors, batteries, or both–and can hit 75 miles per hour in as little as 4.6 seconds.

The competition, started in 2006 by Dartmouth College’s Thayer School of Engineering, gives a glimpse of the possibilities of electric drive, which can throw cars forward with instantly available torque. In comparison, conventional gas engines seem sluggish and unresponsive.

The team from Brigham Young University brought a “family-friendly” sports car that could be easily programmed to limit the power and top speed, depending on who is driving it, at the flip of a switch. The University of Manitoba team is patenting its design, which includes a new transmission system with two electric motors. This system allows the car to capture different amounts of energy from the inner and outer wheels to smoothly slow the car when it goes into turns, and delivers different amounts of power to the wheels to speed them out of turns. It can also use all of the two electric motors’ instant torque with a high initial gear ratio of 12.5 to 1. (It’s called a “continuously variable planetary gear transmission”.)

Credit: Kathryn LoConte / Thayer School of Engineering at Dartmouth.

Joshua Campbell from the University of Manitoba, points to the continuously variable planetary gear transmission that he invented. It allows independent gear ratios for each wheel to help in turns.

Credit: Kathryn LoConte / Thayer School of Engineering at Dartmouth

The Dartmouth team’s vehicle uses a custom controller in the steering wheel for electrical braking and acceleration. “It feels like a video game,” says Erik Bell, the team’s captain.

Credit: Kevin Bullis.

The Dartmouth controller features an LED display at the top that changes from red to green to show the amount of energy stored up in ultracapacitors.

Credit: Kevin Bullis.

One paddle controls the amount of regenerative braking–that is, how much the car slows down as kinetic energy is converted to electricity and stored in ultracapacitors. The other releases that energy, giving the car a boost of acceleration.

Credit: Kevin Bullis.

Thick orange cables deliver power in BYU’s “family friendly” race car.