Engine operation control for an electromagnetic coupling dual electric machine hybrid electric bus

An electromagnetic coupling dual electric machine hybrid electric bus is investigated. The flywheel and start-motor of the Internal Combustion Engine (ICE), the mechanical clutch and the manual transmission are replaced by Double-electric Machines (DM). The DM work as an electromagnetic clutch and a continuously variable transmission, simultaneously. An Improved Engine Operation Control (IEOC) is proposed to maximise the efficiency of the overall electromagnetic coupling system, in which the ICE efficiency, the DM efficiencies and the battery efficiency are all explicitly taken into account. Simulation results indicate potential fuel economy improvement relative to the traditional control.