Implementation of a Wind Turbine System as a Native C-Code MATLAB Model for Parameter Estimation Application

Renewable energy is a very current topic internationally and also in the local South African context. Wind energy is one of the sources that the South African utility is investigating to achieve the target of a cumulative 10 TWh renewable energy component by 2013. It follows that the analysis and prediction of the dynamic behaviour of the entire wind turbine system, i.e. from wind side to power grid side, is gaining in importance. Although the relevant model topologies are well established, obtaining or deriving appropriate parameters from first principles remains problematic. Some parameters are also dependent on operating conditions and are best determined from site measurements using system identification and parameter estimation methodologies. This paper discusses the implementation of a wind turbine system as a native C-Code MATLAB model for parameter estimation applications. An overview of the parameter estimation process and a discussion of the building blocks of the process are presented, followed by a review of the derivation of the model topologies for the different components of the Wind Turbine System, namely turbine blade, gearbox and generator. Implementation of these models as native C-code S-function Simulink models for high-speed parameter estimation applications are discussed, including a short discussion of the S-function functionality of MATLAB's Simulink platform and implementation of a C-code model as an S-function. Model performance is validated using simulated input/output data.