Fault Location in a Zonal DC Marine Power System Using Active Impedance Estimation

Momentum is gathering on the development of dc power systems for naval platforms. However, the necessary accurate location and isolation of faults within the zonal distribution system remains a challenge. The method of “foldback” is an example of a technique which has been developed to exploit the fast control of the supply power converters to maintain bus currents to within acceptable levels. Techniques such as this need to be supported by equipment which can classify and localize the fault, so the fault can be cleared and the system can be reconfigured. A new technology - active impedance estimation - is presented which offers benefits to future marine power systems, and its application to dc zonal distribution systems is discussed. Experimental results from a dc system demonstrator show the potential of the new technique for fault location.