Design of a grid-simulator for a transient analysis of grid-connected renewable energy system

This paper describes a design of grid-simulator for an experiment of transient stability of grid-connected renewable energy system. A transient analysis of renewable energy system has been researched by a simulation, because a direct connection of renewable energy system to the real utility under transient grid conditions is dangerous and it is hard to produce the transient grid conditions with direct grid connection. If a grid-simulator is used in the transient stability experiment, the transient grid condition might be generated easily using reference data without any impact on the grid. A back-to-back converter was employed as a grid-simulator. The grid-simulator was designed by simulation with PSCAD/EMTDC. In order to confirm its physical operational characteristics, the grid-simulator was manufactured and its experiment results showed that the grid-simulator could generate transient grid conditions without any influence to the grid.