Research on fault diagnosis method of transformer winding loosing

摘要

Latent winding loosing fault will occur in power transformer after several short circuit current (I) impact, which will affect the operation condition of transformer. In order to research diagnosis method of transformer winding loosing fault, aiming at a 35kV transformer, the vibration mathematic model of transformer winding is established in this paper. The monitor platform on vibration signals is built. The 85% and 100% short circuit current (I) impact experiments are made. Load experiment is made before and after short circuit current (I) impact on the transformer, and the vibration signals of winding are tested. The energy entropy method is adopted in order to calculate features, and winding loosing fault is diagnosed. Experimental conclusions indicate that change rates of feature are 22% and 56% when winding loosing fault occurs, and diagnosis results agree with the actual condition of transformer, which calibrates the availability of the diagnosis method.