Transformer Fault Analysis Using Finite Element Method and Frequency Response Analysis

Abstract

With the appearance of deregulation, distribution transformer predictive maintenance is becoming more important for utilities to prevent forced outages with the consequential costs. To detect and diagnose a transformer internal fault requires a transformer model to simulate these faults This Paper presents here an approach has been shown for transformer fault analysis. A transformer model was designed for a 10 MVA, 132/66 kV three phase system. Data for all the parameters essential for designing a transformer were calculated, after studying machine designing. The next task was to calculate the inductance and capacitance (lumped values) which is later on used to make the ladder network which represents the transformer as inductance capacitance model. After dividing the total inductance and capacitance into segments the ladder network is ready to be used for short circuit fault analysis. Artifi cial faults were created by shorting a few segments at a time and the output voltage corresponding to input voltage under different faulty conditions were noted down. These values were used to create a frequency response curve which was compared with the response under normal condition and further analysis was done.