Distance Protection Challenges of Converter-Interfaced Renewable Energy Sources

Full-scale converter-interfaced renewable energy sources (CIRESs) can cause misoperation of distance relays installed in their vicinity. Such failure stems from the different fault behavior of CIRESs compared to synchronous generators (SGs), based on which existing relays have been developed. Several measures have been devised to improve the performance of distance protection by modifying existing relays. This thesis proposes a new approach to tackle this problem. The prime objective of this method is to mimic certain features of SGs' fault current while the constraints of a converter, such as its limited fault current magnitude, are satisfied. As a result, correct operation of distance relays close to CIRESs is ensured regardless of the fault characteristics, including its type, resistance, and location. Some salient features of the proposed method are its simplicity, compatibility with off-the-shelf relays, independence from the voltage and power rating of the CIRES, using only local measurements and being cost-effective.