A hierarchical generation control in wind parks taking into account operator power and frequency regulation issues

As a result of increasing environmental concern, more and more electricity is generated from renewable sources. Among the different renewable sources the wind seems the most attractive for the economic convenience and reliability of the technologies that convert wind kinetic energy in electrical one. As a result of this, the wind turbines operation start to influence the behavior of electrical power systems. In particular a problem may arise when the load is low and the wind is strong or however when the frequency is high. Fortunately, the existing technology makes wind turbine power production easily controllable and so it can participate for frequency regulation, complying the TSO (Transmission System Operator) rules. The aim of this paper is so to propose a hierarchical control scheme for a wind park to follow the mandatory requirements of TSO.