Decentralized Composite Controllers for the Power Allocation of the Fuel Cell/Ultracapacitor-Based Auxiliary Power Unit of the More Electric Aircraft

Traditionally, the power allocation of the fuel cell (FC)/ultracapacitor (UC)-based auxiliary power unit (APU) is achieved by using centralized power allocation strategy which suffers from poor flexibility, scalability and reliability. What's worse, the system stability can hardly be guaranteed because of the serious interactions between source converters and power-electronic interfaced loads. In this paper, decentralized composite controllers (DCCs) are proposed to achieve dynamic load power allocation, improve energy efficiency, enhance system's robustness (i.e. realize disturbance and uncertainty rejection), and guarantee the system's global stability in a decentralized way simultaneously. Firstly, analyses on the design and operational principle of the proposed DCCs are deeply studied. Then, simulation results verified the correctness of the theoretical analysis and effectiveness of the proposed DCCs.