Transient performance of battery/fuel cell-based APU on aircraft electric power systems with nonlinear loading

In this paper, a model of a battery/fuel-cell based aircraft auxiliary power unit (APU) is developed. The APU model is integrated into a main power channel of a VSCF aircraft electric power system at the high voltage DC bus. The transient performance of the integrated aircraft electric power system is studied under a large share of nonlinear loads. Moreover, the fuel cell based APU integrated model is extended to study the performance of the AEPS under nonlinear loading along with fully controlled shunt power filters. Several time-domain voltage and current profiles are obtained and investigated. The effect of nonlinear loading on power quality of the AEPS is also investigated and compared to applicable aircraft electric power system standards.