A Mathematical Model of a Multicopter with a Hybrid Power System at a Takeoff

This paper discusses a model of a multicopter with a hybrid power system as an alternative to installations with energy sources exclusively based on electrochemical batteries as the main onboard power source. When using batteries, the flight time is usually limited to 10-20 minutes. The main results of the preliminary analysis and modeling of the working processes of the subsystems of the hybrid power system are presented. Subsystems include an internal combustion engine, a permanent magnet alternator and voltage rectification module, electric motors with propellers, and control systems. The model of a sequential hybrid power system is analyzed at the stage of takeoff of a multicopter. To simulate the electrical machines of a hybrid power system, analytical and numerical calculation methods were used, which made it possible to determine the inductance and phase flux linkage for the generator and electric motors of the multicopter. The developed multicopter dynamics model with restrictions on many parameters made it possible to evaluate the takeoff process to a given height of 10 m. The model showed a decrease in the frequency of rotation of the generator drive motor and a decrease in the supply voltage of onboard consumers. From the simulation results of the presented electrical architecture, it becomes necessary to add a battery to its power branch. The main task of the battery is to stabilize the voltage of onboard consumers in case of a sharp change in the energy balance of power, as well as to perform an emergency landing.