A study on the adaptive dual setting method of the microgrid protective devices considering FRT

Abstract

Microgrid (MG) has emerged as an effective way of distributed generations (DGs) integration. MGs can be operated as a grid-connected or islanded mode. During the fault situation, fault current magnitudes will vary depending on the MG operating mode. Consequently, protecting the MG using conventional methods is a challenging problem. Also, the Fault Ride Through (FRT) concept has not been introduced in the Korean distribution system. FRT is a grid code to maintain the connection of the DG for a while and to support the distribution system by injecting a reactive power when the fault occurs in the power system. Therefore, in this paper, the relay setting values of the MG connected to the DG is proposed considering the FRT. Moreover, using the Hilbert-Transform (HT) of operation mode about the energy of power flow, and adaptive dual setting method is proposed. Finally, the proposed method is validated using the Electro-Magnetic Transients Program (EMTP). © 2020 Korean Institute of Electrical Engineers. All rights reserved.