Structures and methods for controlling losses in printed circuit boards

Abstract

The disclosure relates to printed circuit board motors and specifically to printed circuit boards used in motors and generators. Windings formed from copper on printed circuit boards have been used for purposes of forming antennas, inductors, transformers, and stators that can be incorporated in permanent magnet brushless DC (permanent magnet synchronous) machines. For energy conversion devices using modern permanent magnet materials and PCB stators, the magnetic field is not strongly confined by magnetically susceptible materials. Thus, the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers (for a multilayer configuration) may be significant. The structures disclosed hereinafter reduce the effective resistance in the windings, and therefore reduce the associated losses to achieve a reduced current density in portions of the rotating energy conversion devices. The effect of the disclosed structures is a measurable reduction in loss mechanisms as a function increasing frequency, compared to the currently available devices. These effects are significant in frequency ranges important to energy conversion processes as well as typical control strategies, for example, pulse-width modulation.