A novel diagnosis algorithm of maximum frequency for longitudinal insulation fault of transformer winding

The transformer, as one of the most important equipment in the transmission and transformation systems, is directly related to the safety operations of the power grid. Because of the longitudinal insulation fault of transformer windings occupied the highest proportion in insulation faults, the research for the longitudinal insulation fault is has important significance for power grid. A maximum frequency algorithm is proposed in this paper to diagnose the longitudinal insulation fault in transformer winding. When frequency of maximum are obtained by compare the correlation coefficient of the voltage and current for every winding, the severity of the insulation damage can be determined from maximum frequency. The proposed method has strong fault tolerance and anti-disturbance. It is easy to use, without involving large or complicated equipments and specialized testers. Based on a large number of good results in the simulations of insulation defects with various types, the method is proved effective, practical and feasible.