Model-based control of wind turbines for active power control

This paper addresses the model-based control design of wind turbines using the sector-nonlinearity approach. Building on the Takagi-Sugeno framework, this approach introduces an exact representation of the underlying nonlinear dynamics into the control design. The unified wind turbine control design followed in this study addresses both established (power optimization in the partial load and power limitation in the full-load region) and further requirements for wind turbine systems. An important control objective for wind turbines is the ability to support grid operators with frequency control. To achieve this, an active power control scheme is inherited in the design model such that changes in the power generation can be balanced and the grid frequency may be controlled. First, the derivation of models designed to achieve the multiple control objectives is presented in detail. After that, a unified synthesis procedure based on linear matrix inequalities is discussed and applied. Finally, the quality of the design process is evaluated through simulation studies for representative scenarios.