Chapter 2 - System and Fault Modeling

Abstract

This chapter provides an overview of the main challenges of modeling for very demanding systems, such as wind turbine systems, which require reliability, availability, maintainability, and safety over power conversion efficiency. These issues have begun to stimulate research and development in the wide control community particularly for the installations that need a high degree of sustainability. This represents a key point for offshore wind turbines and wind park installations, since they are characterized by expensive and/or safety critical maintenance work. In this case, a clear conflict exists between ensuring a high degree of availability and reducing maintenance times, which affect the final energy cost. On the other hand, wind turbines have highly nonlinear dynamics, with a stochastic and uncontrollable driving force as input in the form of wind speed, thus representing an interesting challenge also from the modeling point of view. Moreover, a proper mathematical description of the wind turbine system should be able to capture the complete behavior of the process under monitoring, thus providing an important impact on the control design itself. In this way, the fault diagnosis and control schemes could guarantee prescribed performance, whilst also giving a degree of tolerance to possible deviation of characteristic properties or system parameters from standard conditions, if properly included in the wind turbine model itself.