Shape optimization of flexible PCB slotless windings in BLDC machines

Windings printed on flexible circuit board (Flex-PCB) offers the opportunity to improve significantly the performance of slotless BLDC motors since, compared with windings made from copper wire, they may have more complex shapes in addition to a variable conductor cross-section along the winding loops. This paper focuses on the shape optimization of windings printed on FlexPCB using a genetic algorithm. It shows that a gain of about 15% on the motor performance can be reached with windings presenting an elaborated shape compared to windings with a basic shape, similar to that encountered in conventional wire windings.