In this paper, a simulation study is done on the performance of solid state transformer (SST) based micro-grid with implementation of droop control system. SST, which consists of AC-DC converter, DC-DC converter, and DC-AC converter is being employed as the interface between the main grid and the micro-grid. As DC link is introduced at the DC-DC converter side of the SST, voltage and frequency isolation between the main grid and the micro-grid can be achieved. Thus, a frequency droop control system can be implemented at the output of the SST, without affecting the frequency of the main grid. This is an advantage for the active generators of dispersed generation (DG) such as photovoltaic or wind generation system in the micro-grid area, as they have to change their power dispatching based on the frequency droop. Simulation done in Matlab Simulink shows the performance of the developed system.