Study of new ecological magnet wires performances during thermal aging tests

The principal purpose of this work is to investigate the performance of new technologies of electrical insulation (Solgel material top coated with an extrusion layer) intended for winding machines wires. New configurations of coating wire produced by an eco-friendly process, with less environmental impact than conventional ones, are tested and compared. The working method is based on measurements of samples that are produced in accordance with international standards to characterize the electrical and thermal properties of the insulated wires. The performance analysis of insulations is composed of a sequence of dielectric tests and thermal aging tests. This latter test is realized after validation of the basic electrical and mechanical tests. During thermal aging, the parallel capacitance, tangent delta, and Partial Discharge Inception Voltage (PDIV) are measured to investigate the evolution of those dielectric parameters and to compare dielectric behaviour between different configurations of insulating materials. The results of the tests show that an extrusion resin with fillers had a longer lifetime compared with non-filled resins. The concentration of sol-gel influenced the lifetime of insulated wire. This study shows some indicators of thermal improvement, but the percentage of sol-gel used is yet very low and therefore, far from the main objective of using fully sustainable products. The sol-gel formulation tested in higher concentrations had a lower performance of basic mechanical properties required for winding wires. However, the extrusion process for magnet wire insulation is possible and gives good results with pure stable thermoplastic polymer and mineral fillers on extrusion resins.