Pole-Slot Selection Considerations for Double Layer Three-phase Tooth-Coil Wound Electrical Machines

This work presents a combination of top-down and bottom-up design procedures to select a suitable pole-slot combination for a tooth-coil wound machine (TCWM), also known as non-overlapped fractional slot concentrated winding synchronous machine. Top-down features such as size and speed are determined by the intended application and affect the selection of slot and pole number. Bottom-up properties are quantified through key performance indicators (KPI) such as fundamental winding factor, periodicity, cogging multiplier and MMF harmonic leakage factor (HLF). Furthermore a compact and intuitive graphical way of presenting the properties of the double layer TCWMs is shown in this paper for slot number up to 39, highlighting the similarities among machines through the key winding factor concept. Analytical formulas for KPls are presented and the results are compared and visualized with FEM simulations.