Stability of Distribution Networks with Wind Turbines

Abstract

This chapter presents modeling of generators that are used in wind farms such as squirrel cage induction generators (SCIG), doubly fed induction generators (DFIG) and, permanent magnet synchronous generator (PMSG). Installing wind farms must fulfill some rules or requirements. These requirements are developed by transmission system operator in order to guarantee the continuity and stability of the interconnected grid. This chapter presents the stability of two different types of combined wind farms. The first type is based on a combination of SCIG and DFIG wind turbines and known as combined wind farm (CWF). CWF collects the benefits of SCIG and DFIG where SCIG is cheaper compared with DFIG and PMSG. Despite DFIG is expensive, DFIG is more stable than SCIG. CWF is more suitable for developing countries. The second type is based on a combination of modern generators DFIG and PMSG and known as modern combined wind farm (MCWF). MCWF collects the benefits of DFIG and PMSG where DFIG features by its ability to control the active power independently of reactive power while PMSG can operate used for small and medium powers. This chapter discusses the impact of CWF and MCWF on the stability of interconnected electric distribution networks during single line to ground and double lines fault as examples of unsymmetrical and during three phase fault and three phase open circuit fault as examples for symmetrical. Also, this chapter discusses the impact of CWF and MCWF on the stability of interconnected electric distribution networks during different types of operation conditions of electric distribution networks such as voltage sage and over voltage.