Application of differential electric drive in the automotive industry

The safety of an electric vehicle on the highway can be improved by a high rate of acceleration when driving at high speed before overtaking. It can be reached by implementing an electric drive based on two motors. The article considers the stability of the system with two-channel speed control of autonomous electric vehicles. While one channel is a “high-torque” drive, in which the engine is connected through a reducer with a reduction ratio, the second channel is a “high-speed” one, in which a similar-sized engine is connected directly. The summation of the power of the two channels is carried out by using a differential gearbox. The article shows the possibility of achieving stable operation by fixing the speed reference on one channel and regulating it on another channel and presents control algorithms. It also determines the optimal values of the gear ratio of the gearbox of the “high-torque” channel and the switching ratio (share in the transient process) of the high-torque channel with a minimum of the transition process time. The calculations concern a passenger car and a truck weighing up to 7.5 tons. This solution allows for increasing the dynamics of the car, expanding the range of regulation in terms of speed and torque, and improving the energy efficiency of the electrical installation as a whole. Each of the engines in the proposed scheme most of the time operates in a mode close to the nominal.