Separation of electrical and electromechanical losses in magnetic materials

This paper presents a method for separating the hysteresis, eddy current (including anomalous), and electromechanical motion losses of soft magnetic toroidal cores having significant magnetostriction coupling. Relative losses play a major role in material selection for electronic and electric power applications including power converters, transformers, controllers, and filter elements. The relative losses become especially important if the electrical excitation of the magnetic material excites a mechanical resonance of the core. The dynamic behavior and the unusual B-H loop characteristics of toroidal test cores having magnetostrictive properties are compared to results obtained by an electromechanical model for resonant and nonresonant conditions. The mechanical response of the magnetic material to sine and square wave voltage excitations are compared.