On the Characterization of Partial-Discharge Endurance of Dielectric Materials for Aerospace Applications

The increasing voltage and electrothermal stress in aerospace electrical assets, and the presence of unconventional power electronics voltage waveforms, is questing for thorough redesign of insulation systems of electrical asset components. Design criteria which are partial discharge (PD) free, new materials, and, in particular, materials showing increased resistance (endurance) to PD in case of PD inception during operation, are topics that need to be faced and developed rapidly. In such a context, this article proposes an accelerated procedure for the evaluation and comparison of PD endurance, or resilience, capability of candidate insulating materials for aerospace application, which has the advantage to be shorter and more informative of conventional accelerated life tests. This procedure consists of accelerated surface erosion tests, where measurement and monitoring of PD by an innovative approach allows material endurance to PD degradation to be evaluated. Also, criteria to establish algorithms for Dynamic Health Index and for residual life estimation are developed here as take-away of such tests. These algorithms could be applied during operation, upon having developed a robust and automatic PD monitoring tool, as a means to support a condition-based maintenance procedure able to ensure the desired levels of reliability and safety for the electrical asset.