Electrical Properties Comparison: Enamelled-Extruded Wires vs. Conventional Wires

The principal aim of this work is to compare some electrical properties characterized experimentally on samples of enamelled wires developed from two kinds of coating insulation processes. It consists of an evaluation of the dielectric strength, Partial Discharge Inception Voltage (PDIV), and voltage endurance accordingly to IEC standards. Enamelled-extruded wires are evaluated, its insulation comprises an enamel primer on PAI, a second enamel coat of PAI-silica composite produced through the sol-gel process, and a topcoat on PPS resin. The same properties had been characterized on conventional enamelled wire samples (PEI and PAI) for comparison. The breakdown voltage measurements are carried out under 3kV (50Hz), and the lifetime data of twisted pairs samples are collected. The analysis of those results employs the Weibull distribution. The PDIV of these wires is measured, the results obtained show some advantages of the enamelled-extruded wires being 781 V (conventional wire PDIV = 668 V). The lifetime under 3kV (50Hz) has demonstrated an advantage for this type of wire, with α=1616 minutes compared to α=529 minutes for conventional wires. The dielectric strength is very similar between both kind of wires, with α=104.5 V/µm for the enamelled-extruded and α= 109.4 V/µm for the conventional wire. This study shows the increased electrical properties of enamelled-extruded wires compared to conventional ones. This advantage is significant regarding the electrical endurance under high voltage. This kind of insulation has the potential properties to be employed in winding applications and is also an eco-friendly solution compared to the conventional wires.