A Differential Electric Drive for Electric Vehicles with an Independent Power Supply

Abstract

In this paper, we consider the effectiveness of using a twin-engine electric drive from the point of view of acceleration dynamics and energy efficiency. To take into account the acceleration time of the electric vehicle and the energy consumed during the transition process, evaluation criterion G was introduced. By a “twin-engine system” is meant a system of electric drive of a wheel pair through two independent mechanical channels: the first is a “high-torque” channel implemented through the use of a gearbox with a high gear ratio, and the second is a “high-speed” channel implemented through the use of a gearbox with a low gear ratio or without a gearbox at all. The summation of power is carried out by means of a differential gear. We performed mathematical modeling of the operation of such a system. Asynchronous electric drives with vector control, which operate in the torque source mode, are used as electromechanical converters. An algorithm and a system for distributing torque between two channels are developed. The gear ratio of the “high-torque” channel gearbox was optimized by the criterion of G minimum. A quantitative comparison and analysis of transient acceleration processes in single- and twin-engine systems were performed based on the example of a 30-kW electric race car. It is concluded that it is effective to use a twin engine system for specific types of electric vehicles.