Role and technology of the power split apparatus in hybrid electric vehicles

Hybrid Electric Vehicles (HEVs) are an in-between step for the transition from the conventional high-consumption, high-pollution vehicles to the future efficient and clean vehicles. In this paper the main HEV architectures are at first reviewed, focusing on the series-parallel one and the key role played by the power split apparatus within this architecture. Then the two solutions used for implementing the power split, namely the mechanical solution, which is built up around a planetary gear, and the electric one, which is built up around a planetary gear, and the electric one, which is constituted by an electric machine with both rotating members, are read up. At last, a performance comparison of the two solutions is given.