Simulation Analysis of DC Fault Interruption Characteristics of Superconducting Electric Aircraft Propulsion

Environmental issues associated with the aviation industry are getting more attention as air traffic increases. Stringent standards are imposed for fuel consumption and pollution emissions for next-generation aircraft. Superconducting electrical propulsion aircraft (SEPA) have been seen as an efficient way to achieve this goal. High-temperature superconducting (HTS) devices are extensively used in the power system to supply enormous energy. Power is distributed to the different loads via a DC distribution network. However, it will generate an inrush current over ten times higher than the rated current in short-circuit state, which is very harmful to the system. Therefore, it is essential to adopt an appropriate protection scheme. This paper discusses one protection scheme that combines DC vacuum circuit breakers (DC VCB) and resistive superconducting current limiters (RSFCL) for superconducting aircraft applications. Considering problems of cost and loss, the auxiliary capacitor is pre-charged by system voltage, and mechanical elements extinguish the arc. Furthermore, combined with RSFCL, the interrupting environment is fully improved. RSFCL limits fault current, and then the VCB breaks this limited current based on creating an artificial current zero (ACZ). The prospective rated power is 8MW, rated voltage and current are 4 kV and 1 kA, respectively. In this paper, we discuss and simulate switching devices that protect SEPA. The interrupting performance of the circuit breaker is analysed in the DC short-circuit fault that occurs on the transmission line. Finally, the residual energy consumption of different situations is calculated. A comparison is made between using RSFCL with metal oxide varistor (MOV) and just using MOV. The scheme with RSFCL shows a significant advantage in energy consumption.