Failure Analysis of a Turboelectric Distributed Propulsion Aircraft Electrical Network: A Case Study

A number of concepts have been proposed to meet future aircraft performance goals. One such concept under consideration is Turboelectric Distributed Propulsion (TeDP) featuring a large number of superconducting motors powered by two superconducting generators placed on each wingtip and connected through a DC distribution network. A key aspect in any design concept is the ability to prove that the system will exhibit a satisfactory reliability for all intended operating conditions. A common tool to support the calculation of failure rates and reliability is Fault Tree Analysis (FTA), and this will be utilized within this paper. The paper undertakes an architectural level FTA on a NASA proposed TeDP architecture to identify any significant factors contributing to the failure rate of key functionalities within the network. The paper goes on to investigate options for improving the rate of failure of the electrical system, such as installing additional redundant parallel feeders, and quantitatively evaluates the impact these modifications have. The paper concludes with recommendations on the most effective strategies for improving network reliability.