High-precision modeling and simulation of distributed propulsion energy systems for eVTOL/eSTOL

Addressing the challenges posed by drastic power load variations and high losses in complex transmission systems for distributed electric propulsion aircraft such as electric Vertical Take-Off and Landing/electric Short Take-Off and Landing (eVTOL/eSTOL), this paper proposes a high-precision power and energy system modeling and evaluation method applicable to the entire flight process of unmanned aerial vehicles (UAVs). We first establish an energy system model based on a second-order RC battery model, identifying key parameters through a particle swarm algorithm using battery discharge experimental data, and construct a propulsion system model including propellers, motors, Electronic Speed Controllers (ESCs), and transmission cables. Subsequently, a working state calculation framework for the UAV power and energy system based on an implicit function equation system is introduced and validated against experimental data. Finally, a simulation assessment of the power and energy system is conducted for a specific project involving a distributed electric propulsion UAV, alongside the optimization design of the transmission cable layout. The results indicate that both the voltage prediction error of the energy system and the errors in the system state calculation framework are smaller than 2%. The model accurately reflects the operational state changes of each component throughout the entire flight process, and the optimized transmission cable layout reduces voltage loss by 17.2% and average power loss by 16.36%, thereby verifying the accuracy and validity of the proposed method.