Ad-hoc analytical solution based on local linearisations for doubly-fed induction generator wind turbine electromechanical simulations

This study presents a new methodology to solve the wind turbine modelling based on doubly-fed induction generator (DFIG) technology. The proposed solution allows us to simulate simultaneously a significant number of individuals DFIG submitted to different wind-speed profiles, minimising the computational time costs and avoiding excessive simplifications in comparison with previous solutions. For this proposal, a third-order induction generator model has been considered by the authors. The rotor current-control loops have been modelled through standard PI regulators, discussing in detail rotor voltage expressions and values of the parameters. The global non-linear equation system has been rearranged in state-space forms, by means of local linearisations and using two different software-packages that enable symbolic computation in a collaborative manner. The analytical results have been compared facing a traditional discretised solving methodology to assess the suitability of the proposed solution under different wind-speed conditions. Indeed, simulated and real-measured wind profiles have been considered for this purpose. Finally, a comparison of computational time costs for different time steps, including the effect of the number of wind turbines, is also included in this study.