High electrical power experimental methods to de-risk integrated electrical and carbon fibre composite structure design

Electrification is a key enabling technology for decarbonisation of flight. However, the associated weight of these systems is a major design challenge. Opportunities for weight reduction exist through the integration of the electrical power system with carbon fibre composite (CFC) structures i.e. non-electrically active CFC components in electrical power equipment and minimisation of cable harnesses. However, these new integrated systems introduce new failure modes when CFC, which normally exhibit dielectric behaviours, conduct electrical fault currents. To understand these challenges, the associated material behaviours, including time-variant electrical-thermal behaviour of CFC, must be fully characterised.<br/><br/>Pre-existing experimental methods are limited to lower power levels by existing power supply current and voltage limits. While these studies indicate that glass transition temperature is reached, behaviour prediction at higher power levels is reliant on extrapolation and modelling. Therefore, this paper will present an experimental methodology to capture electrical-thermal response of CFC at aircraft high voltage levels. A capacitive discharge rig is used to control the applied voltage level and electrical fault duration, without current limitation. The paper will explore the ability of both experiments and modelling to replicate the electrical-thermal response of CFC within modern aircraft electrical power system models, thus directly de-risking integrated systems design.