Eddy currents in anisotropic composites applied to pulsed machinery

Abstract

Pulsed electrical machines such as the compensated pulsed alternator (compulsator) are increasingly being considered for mobile applications. Size and weight reduction in these machines is therefore very important. Composite materials, such as carbon fiber and glass fiber epoxy composites, with high strength and low density are a natural choice for the various structural components of these electrical machines. The carbon fiber-epoxy composite (CFC) is particularly useful because of its high strength and modulus. However, this composite (CFC) is electrically conductive with greatly different electrical conductivities along the fibers and transverse to the fibers. When these materials are used in pulsed machines, it is important that the designer be cognizant of the conductivity and treat the anisotropy adequately. This paper illustrates how the eddy current distribution can be determined in carbon fiber composites in light of the anisotropy.