Reliability-Based Sizing of Electric Propulsion System for Turboelectric Aircraft

Aviation industry is moving towards more electric aircraft, where both non-propulsive and propulsive loads are electrified. While bringing in various benefits, electric propulsion system (EPS) introduces extra complexity and weight to aircraft, as well as raises the reliability concern. New design and analysis tools are required to size the EPS while meeting stringent reliability requirements. This paper investigates how to consolidate readability into the EPS sizing process and makes two-fold contributions. First, a probabilistic algorithm is proposed to assess the reliability of the EPS admitting a directed acyclic graph topology. The algorithm reduces the directed acyclic graph to a layered tree, which simplifies the calculation of joint probability of nodes in each layer. Second, we formulate the reliability-based EPS sizing as an integer nonlinear programming problem, where the reliability requirements are posed as constraints. Preliminary simulation validates the proposed method.