High-Impedance and Low-Impedance Fault Protection Requirements and Verification Testing for Electric Aircraft Power Systems

Electric- and hybrid-electric vertical takeoff and landing (eVTOL) aircraft are essential to the success of many of the advanced air mobility (AAM) air transportation systems. High-voltage direct current (HVDC) architectures have received most of the aviation industry’s focus in electrical power system (EPS) research, but requirements of HVDC power systems have not yet been defined for these aircraft. This paper will describe a method of high-impedance and low-impedance fault verification testing per requirements for developing HVDC power quality standard(s). Two novel fault injection test systems were developed. The first method uses parallel integrated bipolar junction transistors (IGBTs) to switch high-impedance faults onto a HVDC bus, and the second uses an integrated gate-commutated thyristor (IGCT) to switch low-impedance faults onto a DC bus. This paper demonstrates hardware design and fabrication, power quality testing procedure, and test results.