Performance Evaluation of a High-Speed Permanent Magnet Synchronous Machine with Hairpin Winding Technology

High speed machines offer several advantages such as reduction in size, low noise, mechanical gear avoidance and integrated design for many industrial applications with limited installation space. In recent times, rectangular wire winding, also known as hairpin winding, has gained prominence in many traction applications due to their high slot fill factor, good thermal heat dissipation characteristics, strong mechanical properties and relatively easy manufacturability. However, they also suffer from AC copper losses at high frequencies due to skin- and proximity-effects. This paper presents the performance evaluation of a 10 kW (continuous) - 120000 rpm high-speed permanent magnet synchronous machine equipped with rectangular wire windings to be used as an electrical compressor in fuel cell applications. Comparison with a similar machine with round bundled wires reveals the critical design aspects to be considered.