Criteria for inter-winding fault detection within power transformers

Power transformers are highly valued power system´s elements, transformers failure may lead to high scale system´s operations disruption and heavy economic losses. This is the main reason for power transformer protection requirements to be so high. Sensitivity level is a key element in inter-winding faults detection. Incomplete winding faults that occur in the multi-wire transformer windings, when multiple parallel wires form a coil, are very hard to detect, this is why it is the most challenging issue for the differential protection. This paper presents the development of a criteria for inter-winding fault detection.