Distribution network adopts flexible interconnection devices such as Distribution Unified Power Flow Controller (DUPFC), which can realize flexible regulation of power flow and improve the consumption level of distributed new energy. In this paper, for the distribution network equipped with DUPFC, the protection action process of DUPFC device under faults is analyzed. Based on the fast operation characteristics of DUPFC, the equivalent calculation model of DUPFC is established. Based on power system network theory and superposition method, this paper proposes a fast calculation method of two-stage short-circuit current for distribution network with DUPFC. Finally, the accuracy of the proposed short-circuit current calculation method is verified by simulation in PSCAD.Distribution network adopts flexible interconnection devices such as Distribution Unified Power Flow Controller (DUPFC), which can realize flexible regulation of power flow and improve the consumption level of distributed new energy. In this paper, for the distribution network equipped with DUPFC, the protection action process of DUPFC device under faults is analyzed. Based on the fast operation characteristics of DUPFC, the equivalent calculation model of DUPFC is established. Based on power system network theory and superposition method, this paper proposes a fast calculation method of two-stage short-circuit current for distribution network with DUPFC. Finally, the accuracy of the proposed short-circuit current calculation method is verified by simulation in PSCAD.

Distribution Unified Power Flow Controller,distribution network,power system network theory,PSCAD simulation,short-circuit current