Comparative Study of Dynamical Requirement Impacts on System Design of Notional Aircraft Dc and Ac Electric Power Systems

In future aircraft electric power systems (EPSs), the dc distribution is regarded as a promising substitution for conventional ac distribution because of the reduced weight. However, the assessment of weight reduction is usually obtained under the system static performance requirements. Dynamical requirements, including small-signal stability, normal load transient, and abnormal transient have not been fully considered. Therefore, this paper aims at bridging this gap by providing a design example under comprehensive system requirements to study the impacts of dynamical requirements on dc and ac, separately. It is seen that if only static requirements are considered, dc EPS is lighter than ac mainly due to the lighter feeders. But if dynamical requirements are factored in, the notional dc EPS will need additional energy storage systems (ESS) and protection devices because it lacks energy storage capability and has faster fault current dynamics intrinsically, comparing with the notional ac EPS.