Under the circumstance of peak carbon dioxide emissions and carbon neutrality

various of challenges appear during conversion from conventional distribution system to new distribution system. The access of distributed photovoltaic（PV） changes the characteristic of single source and unidirectional power flow in distribution network. Current protection and reclosing can not longer adapt to new distribution system which integrates source

grid

load and storage. Based on the simplified topology of distribution network with distributed PV

the relative position between PV and fault is assorted. The impact on relay protection is evaluated via analyzing the transient characteristic of voltage and current under different types of fault. Modeling and simulation on RTDS validate the proposed analysis of impact

lastly methods as directional protection and setting value modifying are proposed to improve the reliability of relay protection.