Abstract. This paper proposes an optimal EnergyManagement System (EMS) based on Mixed Integer Linear Programming (MILP) optimization technique for an islanded Microgrid (MG). A local energy market (LEM) platform is employed which attempts to obtain the best electricity market price and to maximize the utilization of existing distributed energy resources. Besides, a single side auction market structure is used for the LEM which takes the offer prices from all microsources to calculate market clearing price. Simulation and experimental results from the proposed method over a real MG are compared with those from a Modified Conventional EMS (MCEMS). The proposed algorithm is flexible, extendable and too fast to be utilized for different MG structures with various capacities. The results demonstrate the effectiveness of the proposed method to solve the optimal operation problem in an isolated MG with 25% reduction in the cost of operation. Key words

This paper discusses the impact of wind turbine generation systems operation connected to power systems, and describes the main power quality parameters and requirements on such generations. Furthermore, it deals with the complexities of modeling wind turbine generation systems connected to the power grid, i.e. modeling of electrical, mechanical and aerodynamic components of the wind turbine system, including the active and reactive power control. In order to analyze power quality phenomena related to wind power generation, digital computer simulation is required to solve the complex differential equations. Other important factors analyzed in this paper are grid connection requirements for connecting large wind farms to the power grid, specified by system operators all over Europe. The requirements, which include voltage and frequency stability, the ability to supply reactive power and responses to fault conditions, and active power control and power factor, are compared by the most important European wind power producers. Finally, a methodology for impact determination is proposed.