A Stable and Robust DC Power System for More Electric Aircraft

'More Electric Aircraft' (MEA) is a trend for medium and long haul airliners, in which all functions except propulsion are powered by engine-driven electrical generators. Power systems for MEA are in the process of rapid development. Constant Power Loads (CPL) pose a big challenge for power system stability. This paper proposes a concept of a MEA power system with a common DC bus, where power sharing between generators is achieved without droop or explicit communication. The paper shows how a coordinated response can be achieved by multiple DC-DC converters under PI current control, based on the local current measurements only. It utilises advanced control concepts, including feedforward and multiple degrees-of-freedom design. The paper demonstrates stability of the proposed power system with respect to any load type, including CPL. The findings of the paper are validated by detailed simulations and preliminary experimental results.