This paper analyzes the effect of superconducting magnetic energy storage (SMES) to improve the stability of the distribution network with a photovoltaic (PV) system and plug-in battery electric vehicles (PBEVs). The PBEVs are expected to play a major role in making the transport system. The charge of their batteries by the penetration of PBEVs results in an increase of peak demand. Also, the output power fluctuation from a large-scale PV system due to the weather conditions often causes instability of the system. To handle these problems, the SMES is applied in this paper. To analyze the effects of SMES on the system stability, several important factors such as the capacity of SMES, its regulation for grid-connection, power reserve margin, the charging scenario of battery, the output power fluctuation of the PV system, and the seasonal load demands, etc., are considered with field measurement data. The performances of the SMES are evaluated and verified with the PSCAD/EMTDC based simulation test.