Summary
This chapter reviews the existing literature related to wind farm protection and identifies important aspects worth considering for the design of protection for the various WTG types. It discussed the interconnection of wind units to the grid through multiple hierarchies and identifies possible areas where protection system or relays could be installed. Later, in this chapter a case study involving Type-1– Type-4 type WTGs is carried out, recording the fault current data for each type during a similar fault condition. Results obtained from the mentioned case study, developed in DIgSILENT® PowerFactory, have been utilized to analyze the fault behavior of four common WTG types. WTG type equivalent short-circuit models are presented to form the basis of comparative fault behavior study. The responses have been then generalized to an extent and compared to analyze their impacts on protection operation and performance under a weak grid interconnection. Distance, differential, and overcurrent protection operation and performance have been assessed for each WTG type. The chapter further identifies impacts on fault current because of three major aspects of modeling. These aspects include mechanical model order type, time step, crowbar protection, and additional controls. All these aspects have significant impact to achieve the correct current magnitudes for protection relay configuration. Practical challenges and implementation issues identified can be addressed by improving cooperation among wind generators, transmission system operators, and researchers.