Active control: Wind turbine model

This report is a part of the reporting of the work done in the project 'Active Control of Wind Turbines'. This project aim is to develop a simulation model for design of control systems for turbines with pitch control and to use that model to designcontrollers. This report describes the model developed for controller design and analysis.

Emphasis has been put on establishment of simple models describing the dynamic behavior of the wind turbine in adequate details for controller design. This hasbeen done with extensive use of measurements as the basis for selection of model complexity and model validation as well as parameter estimation.

The model includes a simple model of the structure of the turbine including tower and flapwise blade bending,a detailed model of the gear box and induction generator, a linearized aerodynamic model including modelling of induction lag and actuator and sensor models. The models are all formulated as linear differential equations.

The models are validated throughcomparisons with measurements performed on a Vestas WD 34 400 kW wind turbine. It is shown from a control point of view simple linear models can be used to describe the dynamic behavior of a pitch controlled wind turbine. The model and the measurementscorresponds well in the relevant frequency range.

The developed model is therefore applicable for controller design.