Application of Gauss-Newton Iteration Algorithm on Winding Radial Deformation Diagnosis

The ultimate objective for transformer winding fault diagnosis is fault location and even severity evaluation. The issue has been studied in many works, based on frequency response analysis, using numerical indices or mathematical correlation between ladder network and winding. This paper utilizes Gauss-Newton iteration algorithm (GNIA) to diagnose winding faults for its efficient search of optimal parameters and discrimination of linearly-dependent vectors. Three key problems are handled for the application of GNIA in this paper. The first problem is the establishment of connection between ladder network components and frequency response function in GNIA. Another issue is the method to identify the faulty section to locate the defective winding position. The assessment of fault severity with GNIA data is another challenge. GNIA is applied on an air-cored model coil and a customized transformer successfully, with satisfactory diagnosis on deformation location and severity.