Distributed Power Management Strategy for Multistack Fuel Cell Systems in Electric Propulsion Aircraft With Efficiency Reinforcement

To realize aviation electrification, fuel cell stacks are promising energy sources to serve distributed propulsors in electric propulsion aircraft (EPA), and both the sources and loads can be installed in different locations in the fuselage for energy optimization. In such power systems, propulsion power sharing between parallel fuel cell stacks is a vital issue for efficient and reliable operation. However, it is always degraded by the mismatches between line impedances and power ratings of fuel cell stacks. Besides, the operational efficiency of fuel cell stacks varies with output power. To enhance the efficient operation of multistack fuel cell systems, a distributed power-sharing strategy is proposed in this article, and the output power and the number of the activated fuel cell stacks are regarded as two degrees of freedom. In this strategy, the number of activated fuel cell stacks is determined by the required propulsion power, and the output powers of these parallel units are regulated in the same way as the adaptive droop coefficient regulation. With this strategy, both power sharing between activated units and efficient operation of whole power systems are simultaneously realized. The effectiveness of this strategy is validated with simulation results.