Optimization of wind turbine operation in an islanded microgrid

Microgrid concept provides an appropriate context for installing distributed generation resources and providing reliability and power quality for sensitive loads. However, presence of intermittent energy resources like wind turbines and solar cells may affect the microgrid performance due to the close production and consumption levels. In this paper, model of a wind turbine equipped with a doubly fed induction generator system is presented which is capable of operating in islanded mode by decentralized power control method based on active power-frequency and reactive power-voltage droop characteristics. Using this precise modeling approach, small signal stability of the entire system is assessed and then improved based on eigenvalue analysis. Simulated annealing algorithm is used to enhance stability margin and damping ratio of critical modes. Through simulation in a sample microgrid environment, accuracy of the proposed control method and the optimization process is verified. Finally, control system parameters are optimized to ensure stable operation in different loading conditions of the islanded microgrid.