Determining the influence of structural and electromagnetic parameters on active losses in an electric motor with permanent magnets for unmanned aerial vehicles

This study investigates a small-sized high-speed permanent magnet motor used in the drive of unmanned aerial vehicles. As part of this study, a numerical simulation field mathematical model of a high-speed permanent magnet motor has been built, implemented by the finite element method. That made it possible to obtain the distribution of the electromagnetic field and forces, to estimate the total losses in all conductive and magnetically conductive media in individual structural elements of the permanent magnet motor under study. Unlike existing ones, the model built enables deriving the total losses in the calculation area; in permanent magnets, structural conductive elements, the armature winding, and in the magnetic core with hysteresis losses, eddy currents and additional losses caused by higher harmonics. The task addressed is predetermined by the pressing scientific-practical issue related to increasing the energy efficiency of a high-speed permanent magnet motor used for electric transport systems and unmanned aerial vehicles. The use of a simplified, more technological rectangular shape of permanent magnets has been proposed. Applying permanent magnets of this configuration makes it possible to reduce the total losses in the motor by 23…41% depending on the type of power supply – sinusoidal or when powered by an inverter with PWM. The use of a more technological form of permanent magnets leads to a decrease in the electromagnetic torque of the motor by approximately 18…30%, which is attributed to a decrease in the volume of active materials and an increase in the value of the equivalent air gap. At the same time, applying a modified form of permanent magnets makes it possible to reduce pulsations of the electromagnetic torque by 12%