Fault location for a DC zonal electrical distribution systems using active impedance estimation

One of the most important issues that need to be resolved before DC power systems are feasible to be introduced as architectures for naval marine power systems (MPS) is the protection of the system against faults. Techniques are being developed to control fault current levels by fast acting control using power electronic systems. These techniques need to be supported by a system that classifies and localizes the fault, so the fault can be cleared and the system reconfigured. Active Impedance Estimation (AIE) can be used to provide information on both fault severity and fault location such that the power system can be correctly reconfigured. This paper describes a 50kW five zone, two bus, DC system demonstrator and presents initial results which show how AIE can be used to inform a MPS reconfiguration algorithm to achieve system “self healing” in the event of bus faults.