Sensitivity of identified transfer functions in transformer diagnosis

The performance of a new transformer diagnosis method is tested experimentally. The method is called model-based diagnosis because the diagnosis is based on an identified model of the component, i.e., the transfer function. A single test series is carried out in order to evaluate the sensitivity of the method in transformer diagnosis. The basic purpose of this sensitivity test series is to determine how close the identified transformer model is connected to the physical condition of the modeled transformer. Based on the results of the sensitivity test series it is concluded that the detection of failures and aging phenomena in transformers by transfer functions is dependent on detectable changes in relatively few characteristic transformer parameters, i.e., basically lumped winding capacitances, total losses and core reluctance.