A disk-to-disk breakdown and arc modeling method for fault diagnosis of power transformers during impulse testing

Impulse tests are performed on power transformers to assess their insulation integrity. During these tests, impulse voltages are applied, and the resulting voltage and current waveforms are recorded. After postprocessing of these data, the presence of faults in the winding should be detected. Different methods and models have been developed for pattern recognition of transformer winding current and classification of impulse faults, . The drawback of these methods is the representation of a fault as a short circuit with constant conductance. In this paper, the breakdown and arc were modeled to represent a more realistic fault during impulse tests. Using this model, it is possible to generate more realistic data, which are necessary to develop more reliable fault-detecting algorithms and, as a result, better pattern recognition and classification of impulse test waveforms. The model has its roots in the classical Mayr equation, and it is simulated with TACS and MODELS modules in EMTP. The simulation results verify the ability of the suggested method to represent disk-to-disk breakdown and arc fault during impulse testing.