Proposed Wind Turbine Limited- and High-Speed Operation

This paper proposes a high-speed operation (HSO) scheme for wind turbines. In the HSO the turbine can exceed the rated rotor speed while it maintains its output power. The HSO is compared with the existing industry standard for wind turbine control, here referred to as limited speed operation (LSO) where the turbine rotor speed is controlled below the rated speed. Compared to LSO the HSO results in reduced torque for the turbine generator. The paper presents analytical models for the turbine power coefficient, which is used to estimate the turbine power and torque characteristics. The developed models are examined on a commercial wind turbine, Enercon E-82 2 MW, which confirm the effectiveness and accuracy of the methods. Analyses of blade pitch angle and its effect on the turbine characteristics are presented and compared in LSO and HSO schemes.