Wind farm stability analysis in the presence of variable-speed generators

Variable-speed technologies have been adopted to improve the efficiency of electricity generation in wind farms. Among these technologies, doubly-fed induction generators have widely spread and their stability issues have been experienced and analysed. In recent years, permanent-magnet synchronous generators have been also exploited, connected to the grid through full-scale converters, ensuring high flexibility, reducing losses and weight. The presence of these technologies heightens the necessity of deeply investigating wind turbine behaviour under different disturbances.