Design and Evaluation of Electric Propulsion System for Electric VTOL

Electric vertical take-off and landing aircraft (eVTOL) has become a main trend in general aviation. Battery, power electronic and motor have made big progress in the last decades, most companies and research institutions are focusing on the development of 2-5 seat (2 tons maximum takeoff weight) eVTOL products and strat to put into market. This paper tried to defines the design and analysis process of electric propulsion system taking 2-ton eVTOL as an example. Firstly, the parameters of the aircraft is defined and the power and energy consumption was analyzed based on flight phase. Secondly, the electric propulsion system architecture is defined based on the aircraft design. The design and evaluation of propeller, motor, motor controller and battery were carried out respectively. The optimal design of propeller in hover stage and cruise stage is conducted. Based on the existing products, the selection of the motor and motor controller are conducted, and the matching design with the propeller is analyzed. According to the power and energy requirements of the aircraft, the tradeoff of battery energy density and discharge rate is performed. Finally, the power and energy consumption are re-checked for flight phase. Based on the evaluation in this paper, it is concluded that the current technical status of battery and electric propulsion system can meet the target of 200km range.