An Operation Algorithm of Real Time Intelligent Blackout Protection Device in LVDC Distribution System

This paper classifies the slope characteristics of fault current considering the line impedance and load capacity, and then proposes an operation algorithm of a real-time intelligent blackout protection device (IBPD) to detect fault conditions rapidly. The operation algorithm of real-time IBPD is composed of fault detection and protection operation algorithms. The former detects the fault conditions by recalculating the reference slope of real-time IBPD based on the predictive model of MATLAB S/W. The latter limits the fault current rapidly and accurately using the control of semiconductor switches to induce the fault current to the CLR (current limit resistor) path. The simulation results of the operation characteristics in real-time IBPD based on various scenarios showed that the fault conditions can be detected accurately by recalculating the reference slope in a real-time manner. In addition, the fault current can be limited within several [㎲]. Therefore, the proposed real-time IBPD could minimize the outage area by effectively preventing the main converter from shutting down in the DC distribution system.