High Voltage Power Transformer Transfer Function Based on Vector Fitting and Experimental Analysis

摘要

One of the most important equipment elements in HV transmission systems are transformers. Therefore, improvement techniques for transformer life assessment have been developed in recent years. Frequency Response Analysis (FRA) is a useful method for the reliable detection of electrical and mechanical faults in transformers. The point to be further emphasised in FRA is interpreting deviations in order to identify the failures .In this research an algorithm for automated analysis is developed based on analytical model results by approximating measurement data to a rational function to obtain minimum complexity by using the vector fitting method. The Root-Mean-Square (RMS) between the measured data and proposed-fitted transfer function is determined by searching the number of complex and real starting poles as well as, number of iterations, linear or non-linear distribution of the proposed poles over the reference measured frequency range is determined as well besides finding the order of the approximation function that consequently represents the transformer?s transfer function. A MATLAB software program has been implemented for the vector fitting algorithm with the measured data.