Experimental validation of protection blinding on DC aircraft electrical power systems with power-dense energy storage

Power-dense energy storage systems (ESS) are being considered to maintain power quality of DC power distribution systems on future more electric aircraft (MEA). However, during high impedance fault conditions, the behaviour of such sources can dampen the fault response of converter fed primary generation, resulting in protection blinding. This paper reports on the experimental validation of protection blinding on a scaled down, low voltage DC power system testing facility and the impact on the performance of a commercial solid-state power controller. It is shown that the inherent response of a fast acting and power-dense ESS integrated at a downstream location on the network can significantly increase the trip-time of a conventional i²t based generator feeder protection device during such conditions. A more configurable protection device with adaptive settings that enables more consistent protection performance to mitigate the protection blinding effects caused by ESS integration is also proposed and verified experimentally.