Insights into Methods for Electric Machine Winding Design

The design of the stator winding has direct influence on the electric machine performance. As technology has advanced, researchers and motor manufacturers have worked on possible ways to improve the stator winding layout to achieve several targets depending on the application which namely consist of minimization of harmonic losses for improved efficiency, torque pulsation reduction, acoustic noise and vibration reduction,... For this purpose, an extensive range of literature have presented several design strategies for both synchronous and induction motors acting on winding connection types, configurations, conductors type and shape..., to achieve the required electrical performance. It has been shown that - depending on the application - some winding configurations can be more problematic than others as they produce additional undesirable parasitic effects. However, in some cases, the choice of the winding layout is limited by the required application which leads to look for solutions to cope with the winding configuration drawbacks. The works presented in this thesis will deal with two different aspects of electrical machine windings that need to be further explored which consist of: fractional slot concentrated winding optimization in three-permanent magnet machines and study and improvement of the winding in terms of skin effect is large-medium voltage synchronous machines. Regarding the first topic, potentials and limits of the FSCW optimization through multi-layer arrangement will be presented to mitigate three problems: unbalanced magnetic pull (UMP), torque ripple and permanent-magnet eddy-current losses. As for the second topic, an extensive study of the eddy-currents losses in the stator equipped with form wound coils made of flat conductors embedded in open slots will be covered. Such study is important as it helps to identify the main causes of problems to avoid it through a suitable design.