Manufacturing and Testing of AC HTS-2 Coil for Small Electrical Motor

The paper describes manufacturing and testing of HTS double racetrack coils intended for use in stator windings of small-size motor, proposed for electric unmanned air vehicle (UAV). The level of AC losses of the armature characterizes required flow of liquid hydrogen (LH) coolant. Thus, it affects overall configuration of the UAV by LH-tank mass and volume. On the other side, motor will be driven by AC motor controller (inverter), so the armature currents will not be pure sinusoidal, and formed by pulse width modulation (PWM). In this work, the manufactured coil is tested on meander-form AC current with frequencies up to 200 Hz with and without solid ferromagnetic core. In addition, losses on PWM currents were also determined on a specific H-bridge to ensure functionality of HTS coils in such conditions.