Turn-To-Turn Fault Recognition in the Series Winding of an Autotransformer by Differential Protection Methods

Abstract

Recognition of turn-to-turn faults in the series winding of an autotransformer is studied. At one time the conclusion had been drawn regarding a low, even zero, sensitivity of the transformer differential relay protection (TDP) series and distance remote protection to this type of damage. Modern microprocessor-based terminals for transformer protection, in addition to traditional differential current protection with percentage braking, provide sensitive differential protection on return sequence currents. Adaptive differential measurements can become a new tool for detection of developing internal damage. By means of a simulation model of the 500 kV autotransformer, measurements of the above-mentioned algorithms are constructed for turn-to-turn fault in a series winding. Analysis of the obtained results is carried out.