Analysis of tap changers damageability and technical condition evaluation by DGA

The article includes the detailed damaging (both defects, which were found by operating staff, and failures) analysis of tap changers and its units: selector switch, diverter switch and drive. There have been investigated the type and location of defects, reasons and initiators of defect appearance, the influence of operation life and tap changers (TC) construction features on the damaging. The efficiency of different measurement types of tap changers defect detection is evaluated on the data in addition to the analysis of TC reliability. Next the article considers the capabilities and improvements of diverter switch condition control by DGA. On the basis of dispersion analysis is shown the influence degree of number TC switchers, transformer load capacity and TC operation life on the…