A novel approach to VFTO analysis of power transformers including FVL based on Detailed Model

There are two physical models to analyze Very Fast Transient Overvoltage (VFTO) on transformers. These models are multiconductor transmission-line model and Detailed Model. The modeling of windings by the lumped RLCM network (the detailed model) enables the calculation of the currents and voltages using common electrical network analyzing tools (e.g., ATP, Pspice, etc.). In addition, it is possible to consider nonlinearities (e.g., hysteresis, saturation) and frequency dependent effects (e.g., eddy current, dielectric losses). Complex windings can be modeled with several coils, which is not possible for the multi-phase transmission line model. This paper is proposed a complete Detailed Model (DM) that is consisting of Frequency Variable Losses (FVL) and comparison of its results with experimentally results shows that it can be used to analyze the VFTO on transformer easily.