optimal planning of renewable energy-based micro grids considering the reliability cost

In recent years, the local feeding of the required loads in the micro grids has received much attention comparing to the extension of the large fuel-based power plants, which require the development of costly transmission lines. on the other hand, environmental constraints have led to the increasing development of renewable energy sources that can generate electricity in the form of small-scale generation units in micro grids. in this study, an appropriate mixture of renewable sources incorporating the wind turbines, current type tidal generation units and the photovoltaic systems is integrated to the micro grid connected to the energy storage systems. the proposed micro grid can be customized in the coastal regions and islands for supplying required loads. to optimally determine capacity and size of renewable power plants, different metaheuristic algorithms are applied, and among them, the particle swarm optimization methodology is used to minimize cost function of the system including the investment, operation and the reliability costs. to calculate reliability cost of micro grid, variable hazard rate of the assembled elements influenced by change in air and water temperature, wind velocity, tidal stream velocity and sun irradiance is taken into account. load curtailment of the micro grid is occurred due to failure of the assembled elements and the change in renewable sources that both are addressed in the paper. for examining effectiveness of proposed approach, numerical results associated to the planning of a micro grid incorporating renewable sources considering the reliability cost are given.