Microgrid reliability evaluation considering the intermittency effect of renewable energy sources

This paper presents the reliability evaluation of a microgrid system considering the intermittency effect of renewable energy sources such as wind in this study. One of the main objectives of constructing a microgrid system is to ensure reliable power supply to loads in the microgrid. In order to achieve this objective, it is essential to evaluate the reliability of power generation of the microgrid under various uncertainties. Because highly variable wind resources and different operating modes of the microgrid are the major factors to influence the generating capacity of the microgrid in this study. Reliability models of various sub-systems of a 3-MW wind generation system are developed. The sub-systems include wind turbine rotor, gearbox, generator, and interfacing power electronics system. The impact of stochastically varying wind speed to generate power by the wind turbine system is accounted in developing sub-systems reliability model. A Microgrid System Reliability (MSR) model is then developed by integrating the reliability models of wind turbine systems with hydro and storage units in the study microgrid system using the system reliability concept. A Monte Carlo simulation technique is utilized to implement the developed reliability models of wind generation and microgrid systems in Matlab environment. The investigation reveals that maximizing the use of wind generation systems and storage units increases the reliability of power generation of the proposed microgrid system in different operating modes.