An Ultra-High-Speed Starter–Generator with a Magnetic Core of Amorphous Iron for Unmanned Aerial Vehicles

Abstract

Results of research on an ultra-high-speed starter–generator with permanent magnets and tooth windings for unmanned aerial vehicles are presented. Technologies for manufacturing of a stator magnetic core of amorphous iron, as well as methods of selection of the number of pole pairs of an ultra-high-speed starter—generator, are studied, the advantages of amorphous iron are substantiated. A particular stage of the work is devoted to the problems of optimization of the slotted area of a starter–generator on the basis of the criterion of the presence of minimum losses in permanent magnets for eddy currents. To minimize these losses, a multicriterion optimization of the slotted area is performed using the genetic algorithms, as a result of which the losses were a quarter those of the initial variant. A cooling diagram of the synchronous machine in the structure of the turbojet engine is proposed. Thermal calculations are presented. A full-scale mockup with a capacity of 5 kW, rotation frequency of 60000 rpm, power density of 0.2 kg/kW, and coefficient of efficiency 96.4% was created to check the proposed design sequence, as well as to determine the efficiency of using amorphous iron. Initial tests of the experimental mockup backed up the theoretical conclusions and showed that the use of amorphous iron allows reducing the losses in the magnetic core of the stator by five to seven times.