In order to solve the problems in power distribution system such as low load ratio with high redundancy in power apparatus and long recovery time after fault

we propose an uninterrupted power hub（UPH） based on VSC-HVDC

in which several substations are connected through voltage source converters to fulfill load balancing and emergently load shift. Main operation scenarios and control strategies of UPH are analyzed in digital simulation system which validates the advantages of UPH application in distribution grid. Study shows that

by cooperation of fixed VSC and variable VSC in UPH

the total VSC capacity can be decreased comparing to the traditional multi-terminal VSC-HVDC system. UPH provides a new application scheme of VSC-HVDC in distribution grid to improve reliability and reduce redundancy. The research of this paper can provide a reference for the application of flexible DC technology in power distribution system.