A determination method for the optimal operation of controllable generators in micro grids that copes with unstable outputs of renewable energy generation

Abstract

Micro grids are expected to be one of the most useful energy systems in terms of efficient use of renewable energy sources with few adverse effects on the main power grids when the micro grids are operated properly from the viewpoint of balancing the electric power supply and demand. However, it is difficult to maintain the supply-and-demand balance because distributed renewable energy generation (DREG), such as photovoltaic generation systems (PVs) and wind turbine generation systems (WTs), account for a large percentage of the generators in the micro grids. Therefore, an operation planning method considering the uncertainty of prediction is needed for ensuring a stable grids operation. This paper presents an optimization method for operating plans of controllable generators in micro grids that copes with the uncertainty of DREG's outputs. In the proposed method, the optimal operating plans are obtained by using an enumeration method or a preconditioned tabu search (TS). Numerical simulations are carried out for a micro grid model in order to verify the usefulness of the proposed method. © 2013 The Institute of Electrical Engineers of Japan.