Additive Manufactured Copper Conductors: Impedance Characteristics of Samples with Varying Density and Cross-section profile

With additive manufacturing, copper windings and even whole coils can be manufactured in a new, totally different approach than with common manufacturing methods. The coil design is no longer bound to the limitations given by the wires bend radius or the geometric capabilities of winding machines. Therefore, additive manufacturing offers new degrees of freedom for the design of copper windings and thus the design of electric machines. However, the electric properties of printed copper material must be known exactly and should be comparable to solid copper wire. This paper examines the impedance characteristics of additive manufactured copper conductors of two different copper alloys with varying print density and two different cross-section areas. Additionally, copper conductors consisting of multiple twisted subprofiles are examined, emulating stranded conductors. The measurement results are set in relation to an extruded copper profile to ensure comparability. The influence of the skin effect is examined by performing the investigations over a wide frequency range. Furthermore, the effect of different print densities on the effective resistance can be shown clearly. Besides the measurement results, an evaluation of the possible field of application and the limitations is given.