Distance Protection for Lines Connected with Type III Wind Farms: Problems and Solution

Performance of the current line distance protection is impacted by the integration of converter-based renewable resources. This study identifies a certain limitation of the phasor-based distance protection for lines connected with Type III doubly fed induction generator wind farms, primarily caused by frequency variations in current signals due to crowbar operation. The study also offers a mitigation strategy that uses a time domain and can improve relay performance without requiring any new knowledge or infrastructure modifications to the existing implementation. The method can be implemented in relay platform as an alternative to existing phasor-based method. For method validation, we make use of both EMTDC simulations and field data.