Low frequency design criteria for carbon fibre composite casings for aircraft power electronic converters

Two key technologies supporting decarbonisation of aviation are the light-weighting of aircraft structures, and the electrification of on-board power and propulsion systems. Achieving the target high power densities required for electrical power system equipment, including power electronic converters (PEC) is extremely challenging. A modularised electrical power system (EPS) which exploits the use of carbon fibre reinforced polymer (CFRP), rather than aluminium, for non-electrically active components (e.g., casings) for EPS equipment offers an opportunity for more compact, lightweight equipment design. However, existing knowledge of the electrical response of CFRP at a component scale, and how this impacts on the design of systems where electrical and structural systems interact, is limited.

This paper provides a set of low frequency (<200 kHz), component scale models of a quasi-isotropic layup of CFRP, suitable for use with a behavioural simulation model of a 6-switch inverter to investigate the influence of casing on fault response, and enable capture of design criteria for resilient, low frequency design of CFRP casings for PECs. This includes investigation of key design interdependencies including influence of CFRP layup, design of electrical bonding points and interdependencies with wider system design considerations, including protection strategies.