Optimal Voltage Selection for Electrical Power Systems on More Electric Aircraft

With the development of More Electric Aircraft (MEA), adopting higher bus voltage levels is becoming a tendency for onboard Electrical Power Systems (EPSs) to efficiently deliver the increased power ratings and reduce EPS weight. However, this tendency potentially raises the risk of electrical insulation failures. Consequently, selecting optimal bus voltage levels to consider the trade-offs is the key to the design of light, efficient, and safe MEA EPSs. However, the mathematical relationships between the EPS weight/efficiency and bus voltage levels are complex and implicit, making it infeasible to solve this continuous optimisation problem. Facing these challenges, this study proposes an optimisation model to select bus voltage levels by selecting a combination of components, initially without considering cables, from an available component set, to meet voltage and power requirements, while achieving the objectives. Furthermore, the Integrated Converter Component (ICC) concept is proposed to improve feasibility when cables are also considered. Each ICC combines one converter with its lightest input/output cables as a new optional component for the proposed optimisation model. Case studies are provided indicating that the selected optimal bus voltage levels save EPS weight while reducing power losses.