An energy-saving regulation approach based on economic rotational speed and power split feature for more electric turboshaft engine

More electric turboshaft engine is comprised of turboshaft engine and electric machines which are connected to each shaft of the engine. More electric turboshaft engine has great development potential in hybrid electric power systems in automobile and aircraft due to their high power-to-weight ratio. To reduce fuel consumption and environmental pollution, it is essential to design an energy-saving control method that can improve the fuel economy of more electric turboshaft engines within the full range of output power. In this paper, an economic rotational speed and power split feature (E-RSPSF) based compound energy-saving regulation approach is proposed for improving the fuel economy of more electric turboshaft engines. First, based on the configuration of more electric turboshaft engine, considering the power transfer balance constraint of shaft motors, augmented co-working balance equations of more electric turboshaft engine are derived by integrating a motor efficiency map. Second, a hierarchical optimization approach utilizing an improved particle swarm optimization method is presented for solving E-RSPSF based on the augmented co-working balance equations, and an E-RSPSF based regulation approach is formulated for better fuel economy of more electric turboshaft engine. Finally, the reason for the improvement in fuel economy by the E-RSPSF is discussed, and the importance of the actual motor efficiency map in the proposed E-RSPSF based regulation approach is presented. The comparison results show that the proposed energy-saving regulation approach with E-RSPSF considering both the economic rotational speed and power split can achieve a maximum 12.5% decrease in fuel consumption, which is higher than that with either rotational speed regulation or power split regulation.