Aircraft Insulation Design for the More Electrical Aircraft: Challenges and Solutions

This paper considers the design options to achieve
the reliability of random-wound motors fed by silicon carbide
inverters and used for the More Electrical Aircraft (MEA).
Considering the inception of Partial Discharges as the most severe
degradation process, the Partial Discharge Inception Voltage
(PDIV) of non-impregnated and impregnated twisted pairs was
measured feeding the twisted pairs with a silicone carbide inverter
in a partial vacuum. The results show that the margins to ensure
that partial discharges are not incepted during operation are tight
and that switching to multilevel inverters and hairpin geometries
might be necessary if the DC bus voltages will be raised above the
current levels (±270 V).