Study and Investigation of Transformer Turn-to-Turn winding faults using Park's vector

Large Power Transformers are the key elements in the power system network and an unexpected failure can cause widespread blackout with substantial loss of revenue and costs to repair and replace. The Transformer protection scheme and methodology has continuously evolved into sophisticated technology to detect and isolate the fault that impedes the normal operation. However, there are challenges involving internal faults that manifests as a smaller terminal current and are difficult to detect/discriminate. To overcome this problem, Park's vector for the differential current is performed and studied extensively using EMTP-ATP simulations. The cases for smaller winding faults for different system scenario is evaluated for Phase, Negative sequence and Park's approach. Further, with the assistance of in-built programmable logic, the approach was implemented in a relay and tested for various system conditions.