Electronic gears for electric vehicles with wheel motor

A novel electronic gearing is proposed in the propulsion system for an electric vehicle driven directly by a wheel motor. This electronic gearing assembles the parallel and serial connections of batteries and motor windings into four gears to accommodate various driving patterns in the permissible range of speed and torque. The objectives of this invention are to extend the speed range of constant power, as well as to improve the driving performance and efficiency of the vehicle. The proposed electronic gearing is tested on a dynamometer to simulate the ECE40 driving pattern, and the driving range is estimated by measuring the state-of-charge of lead-acid batteries, which are normally used as the power source of electric vehicles. The experimental results show that the efficiency increases in terms of the driving range of electric vehicles.