Compared with the traditional power grid

micro grid has the characteristics of flexible and changeable. Especially

the stand-alone micro grid can work in a variety of operating modes. Different operating modes can bring different economic benefits. Therefore

it is necessary to study the micro grid with various operating modes. Focused on this kind of micro grid

established corresponding economic dispatch model

defined three kinds of scenarios and researched the economic dispatch policy of stand-alone micro grid in different scenarios.Prioritization method used in inner layer and improved particle swarm optimization algorithm used in outer layer are adopted to accomplish the solution of economic operation of the multi-mode micro grid. In the end

on the background of microgrid case of Nanji Island

this paper finds the solution of economic dispatch model in three kinds of scenarios. Simulation results show tha tthe different operating modes have an impact on the economic benefits of the micro grid

and the results verified the correctness of the proposed algorithm and theory.