Modeling and Simulation of Wind Power Generators

Abstract

This chapter presents the various configurations of wind energy systems and the modeling of these systems. Particular emphasis is given to the modeling of the Type III wind‐turbine system, which uses a variable speed wind turbine coupled to a doubly‐fed wound rotor induction machine, and a partial‐rating frequency converter implemented using back‐to‐back connected voltage source converters. Wind turbines may be coupled to squirrel cage induction generators (SCIGs) which are directly connected to the grid. SCIGs always draw reactive power from the grid. The amount of reactive power drawn depends on the power output and the grid voltage. A wind farm may consist of a large number of wind turbines. Each variable‐speed wind turbine generator (WTG) may have its own frequency converter and they may be paralleled on the grid side. Induction machines are commonly used in wind‐turbine generator systems. The chapter presents the per‐unit form of the stator and rotor equations of an induction machine.