Safety and Reliability of High-Voltage Electrical Wiring and Interconnect Systems
AIR7255
This SAE Aerospace Information Report addresses the key factors contributing to high-voltage aging to be considered in EWIS design, manufacture, substantiation (qualification) testing, lot acceptance testing, and installation. Special considerations and information are provided to focus on Advanced Air Mobility applications (including Urban Air Mobility, eVTOL/eSTOL/eCTOL, and hybrid-electric commercial aircraft pursuing certification under 14 CFR 21.17(b), Part 23, Part 25, and/or Part 33), utilizing voltage within the VL-3/VL-4 ranges defined by SAE AIR7502. However, much of the information herein may be relevant to higher voltage levels and other applications.
Rationale: As aviation evolves to meet future sustainability and mobility demands, so must the electrical wiring and interconnect systems (EWIS) utilized in next-generation aircraft. Historically, more-electric aircraft has benefitted from relatively low-voltage power systems [1] where electrical aging is benign. For low-voltage systems, simple insulation resistance (IR) and dielectric withstanding voltage (DWV) tests as a function of working voltage have proven sufficient to eliminate defective interconnect. However, for hybrid-electric and all-electric aircraft utilizing high-voltage (>300V [2][3][4]) systems, it is necessary to address electrical aging in the system safety assessment. For high-voltage systems, while DWV/IR testing is still essential, they alone are insufficient to quantify reliability and more advanced testing is required.
