Minimization of DC-link Capacitance for a DC-link Based Variable Speed Constant Frequency Aircraft Power System

DC-link based Variable Speed Constant Frequency (VSCF) AC power generating system is becoming one of the popular power architectures in the new generation aircrafts. These systems convert the variable frequency AC from the generator to the fixed frequency 400 Hz AC using a voltage source inverter. These inverters use DC-link capacitors that are heavy and space consuming. In aircrafts, the weight requirement is very critical, hence minimizing the DC-link capacitance is one of the major research challenges to achieve high power density in the VSCF power converter. In this paper, novel control strategies to minimize the DC-link capacitance of the AC-DC-AC VSCF power converter are presented. The proposed control strategies enable to achieve 92% reduction in DC-link capacitance value when compared to the conventional control strategy, whilst the control is robust enough to meet MIL-STD-704F transient specification at the inverter output for aircraft AC power supply generation.