Single-Phase DC Crowbar Topologies for Low Voltage Ride Through Fulfillment of High-Power Doubly Fed Induction Generator-Based Wind Turbines

This paper presents two new single-phase crowbar protection topologies, for doubly fed induction generator (DFIG) based wind turbines. These crowbar topologies, can be suitable for fulfilling the low voltage ride through (LVRT) requirements demanded by the grid codes, in next generation of high-power DFIG-based wind turbines, allowing the possibility to use simpler and more cost effective crowbar designs, than the classic three-phase dc crowbar, commonly used among manufacturers. Therefore, this paper compares the differences of the classic three-phase dc crowbar and the new proposed ones, together with the study of the behavior of a prototype of 6.25 MW DFIG, when is affected with severe voltage symmetric and asymmetric voltage dips. Control actions and design ideas are discussed, trying to accomplish the LVRT requirements, concluding by means of simulation results that the proposed new single-phase crowbar topologies can be an attractive alternative crowbar solution, for high-power wind turbines.