Design and Analysis of a High Power Density Brushless DC Motor for a Multi-Rotor Unmanned Aircraft

In air taxis with an electric propulsion system (EPS), the use of multi-rotor has become widespread in order to meet thrust. In these multi-rotor Unmanned Aerial Vehicles (UAVs), one of the main targets is to increase the load capacity by reducing the empty weight of the vehicle as much as possible, and for this, it is desired that the battery pack, electric motor, power electronics topologies in the EPS have as much power densities and efficiency as possible. It is aimed to design a high power density and efficient brushless direct current (BLDC) motor by modeling the entire system for a UAV and determining the requirements. Following the analytical analysis, the design and optimization of the BLDC motor are simulated with the aid of electromagnetic field analysis based on the finite element method. As a result of the analysis, a BLDC motor with 93.6% efficiency and 2.44 kW/kg power density was designed. The electrical load was increased by considering the power density increase studies.