On an Auxiliary Power Unit With Emergency AC Power Output and Its Robust Controls

The development of an auxiliary power unit (APU) with 110 V/60 Hz output from conventional battery, laptop computer battery pack, or other available dc sources and its robust controls are presented in this paper. First, a front-end current-fed push-pull dc/dc converter is designed and implemented. It is used to establish the boosted and well-regulated dc-link voltage for the followed inverter. The quantitative designed feedback controller is augmented with a novel robust tracking error cancellation scheme (RECC) to achieve the desired regulation performance. Then, a full-bridge single-phase pulse-width modulated inverter is established to yield 110 V/60 Hz source for emergency use. In treating the inverter waveform control, the causes of waveform distortion under nonlinear loads are explored. Then a novel robust model following control scheme is proposed accordingly. In the proposed control scheme, the simple model following controller is augmented with a RECC. Theoretic bases of all the proposed control schemes are derived thoroughly. The simulation and experimental evaluations indicate that the developed APU possesses good output voltage waveform under unknown and nonlinear loads.