Evaluation of PCB End-Windings for Low-Voltage Stators of High-Speed Electrical Machines

The state-of-the-art slotted stator windings used in low-voltage, low-power, high-speed electrical machines are wound to a great extent with random round wires. Automating the assembling process is still challenging due to the small stator inner diameter and the difficulties associated with the pull-in technique. Almost all the stators are wound using the trickling method, where the pre-fabricated coils are dropped into the slots. This paper evaluates the suitability of rectangular wires (in the form of a hairpin structure) from a manufacturing standpoint, developing a proof of concept for a novel method. A novel way to connect the end-windings using multi-layer Printed Circuit Boards (PCB), thereby allowing a certain level of automation, is evaluated.