Inrush Current Analysis using FFT for Transformer Protection
This study deals with measurement of different harmonics of current in primary current ofa power transformer at different conditions by FFT (Fast Fourier Transform), THD (TotalHarmonic Distortion) based technique to assess the inrush condition of a powertransformer. It is observed that the second harmonic components are dominant under inrush condition byassessing FFT and THD of primary current of the transformer. Significant differences havebeen noted between the parameters which are found during inrush condition and that of normalcondition and fault condition which may be useful in detection of such inrush condition ofpower transformer.
Keywords - Inrush current; FFT; THD; Power Transformer