Abstract
This chapter presents a slow-dynamics model for HVDC transmission systems that integrates wind farms, especially in offshore applications. This model considers the slow dynamics of the system such as variations on the wind velocity, the dynamics of the mechanical axis of the turbines, and the HVDC cable. However, it neglects the fast dynamics of the converter. The model is nonlinear/nonautonomous, and hence it is analyzed using nonlinear theory instead of the conventional small-signal approach. A formal demonstration of stability is presented. Numerical experiments performed in Open-Modelica complement different sections of the chapter.