Development of a novel AC hybrid concept for a fuel cell-battery hybrid electric aircraft with power electronics switches

A novel hybrid concept is proposed for the drivetrain of a fuel cell/battery hybrid aircraft. The concept puts a battery pack directly on each ac phases of the motor. Therefore, the dc voltage from the battery will be superimposed on the ac voltage of the motor, providing voltage increase directly on the motor phases. This short power boost can be used during high power demand and the system can also serve to recharge the battery during flight. The new design simplifies the drivetrain by completely eliminating the need for a DC/DC converter as used in conventional hybrid system. A new high speed switching architecture has been developed and simulated with a flight profile to test the functionality. The results show good response for dynamic loads with the new hybrid topology and the relation of power and speed of the motor with different battery voltages is examined.