High dv/dt Testing of Coil Winding Insulation Systems for Wide-Bandgap Applications

Abstract

To increase efficiency and reduce material consumption, the increased use of wide-bandgap (WBG) power semiconductor devices becomes indispensable. However, challenges such as the accelerated aging of insulation materials have so far prevented exploiting the full potential of this technology. This paper provides an overview of experiments that can be performed to test insulation systems for their resilience with respect to fast switching transients. To this end, capacitive and inductive specimens are considered. Firstly, the test bench is briefly introduced. Secondly, measurements are performed with standardized twisted pair of enameled wire specimens. The lifetimes at two different voltage slopes are compared, the effect of a consistent discharge at steep voltage slopes is analyzed and the influence of a partial discharge (PD) resistant additive in the enamel is considered. Then, single-tooth coil windings with and without a PD-resistant additive in the enamel are investigated and the influence of an optimized winding configuration demonstrated.