Verhalten von Windkraftanlagen mit doppelt speisenden Asynchrongeneratoren (DFIG) bei Kurzschlüssen und anderen Netzfehlern: Behavior of wind turbines with doubly-fed induction generators (DFIG) in the event of short circuits and other grid faults

Motivated by the energy transition, the electrical energy supply is heading for a generating structure in many countries dominated by generating units connected to the grid with power electronics and with wind turbines and photovoltaic systems leading the way. As a result, the design of the electrical equipment as well as the planning and operation of the power system are increasingly based on the properties of such units. Because of their technical complexity, wind turbines with doubly-fed (induction) generators (DFIG) in particular represent a challenge. This is due to both the properties of the rotating electrical machine coming into play. These are determined by physics and the behavior of the converter that is significantly influenced by control. In this article, the behavior of the current DFIG technology in case of short-circuit faults and other network faults is described. Additionally, a state-of-the-art treatment of DFIGs in the short-circuit standard – which is essential for system design – is explained and a new proposal for treatment in this standard is made. Furthermore, special requirements for network protection are formulated and discussed.