A New Protection Scheme for Low Voltage DC Microgrids

Abstract

The DC microgrid has many benefits that make it an ideal networking mode for distributed power generation. A fundamental problem with DC microgrids is the location and protection against DC faults. A method for diagnosing, detecting, and protecting DC microgrid faults is proposed. On a DC microgrid, the technique can detect short-circuit faults. Using such a microgrid, the behavior under DC fault conditions are observed. The basic idea is to use a derivative inductor current to provide a predictive current emulation model that is based on the modulation of the specific DC-DC converter. Through comparing measured and predicted inductor currents, this method guarantees the protection of the DC microgrid system, which is then used to identify the fault location and remove the fault lines. MATLAB/Simulink simulations are used to confirm the effectiveness of the new proposed method and demonstrate a fast response to short-circuit faults.