Intelligent Distance Relay based on IEC 61850 for DC Zonal Shipboard Microgrid Protection

Abstract

Shipboard microgrids must have adequate protection schemes to be more reliable, provide the ability to prevent the spread of outages, and sustain continuous service to customers. The intelligent distance relay that is presented in this paper provides such an adequate scheme. The relay is performed by an Intelligent Electronic Device (IED) based on the IEC61850 communication network. This relay solves a problem that exists in the conventional distance relays of not protecting the whole line instantaneously. The proposed relay is based on a distance protection scheme that has two stages. Firstly, the fault is detected by applying the Fourier Transform algorithm to the voltage and current measurement while measuring the fault impedance, then comparing it with the reach point. Secondly, the fault location is identified by selecting the correct faulty zone. Then communication signals are sent between the relays based on IEC61850 to determine the appropriate time for isolating the fault. A 550 V DC zonal shipboard microgrid is simulated in MATLAB/SIMULINK environment to apply such a technique. The results prove the accuracy and efficiency of the proposed relay in protecting the whole line.