Transformer Winding Deformation Simulation And Diagnosis Method Research

Power transformer is the important electrical equipment in the power system.Transformer winding deformation is one of the main types of transformer faults. Timelyfinding the winding fault is an important guarantee for normal operation of thetransformer. FRA is a powerful and effective diagnostic method in detecting transformerwinding deformation. Nowadays, this method has been widely used.This thesis, use current source instead of the traditional voltage source power asthe frequency sweep power to do a series of simulation experiments. Changing theparameters of the distribution of transformer winding simulates the winding deformationof each part. Finally the changing rule of the frequency response curve can be got, afterwinding equivalent parameters changes.For the problems of the traditional analysis method. This thesis applied corrosionalgorithm to deal with frequency response curve，and then extract the part of the maindifferences between the frequency response curve. On the basis of this, the correlationcoefficient of each frequency band can be calculated to judge the winding deformation.Compared with traditional method, using this method to test winding deformation ismore accurate.The change of the zero and pole of the transfer function is the nature of thefrequency response curve change. Using the least squares to fit transfer functiongenerates ill-posed problem. But using the method of orthogonal polynomial to fittransfer function of the transformer winding can effectively avoid this problem. Bycomparing the change of the zeros and poles can effectively distinguish transformerwinding deformation.