Single Motor Mechanical Power-Split Transmission for Hybrid Racing Cars

A hybrid vehicle derives its power from two or more distinct sources such as an internal combustion (IC) engine and an electric motor. Based on the mechanical architecture, Hybrid Electric Vehicles can be divided into three categories: parallel hybrids, series hybrids, and power-split hybrids. Parallel hybrids require frequent role reversal due to restrictions on motor power, whereas series hybrids lead to lower efficiency of the whole power train. The power-split hybrids combine the advantages of these two configurations by using one IC engine and two motors. The main objective of this paper is to design a transmission system for a hybrid racing car which is powered by an IC engine and a single electric motor which are arranged so as to represent a unique power-split system. This configuration reduces the need of one motor and allows seamless transition between engine-only with regeneration mode, motor only mode and parallel mode.