Influence by parasitic capacitances on frequency response of a 380-150-50 kV transformer with shunt reactor

Power transformers and shunt reactors in HV systems attract increasing attention for their transient behaviour as nowadays the systems grow more and more complex. Both devices are usually modelled by inductive components at low frequencies (e.g. 50 or 60 Hz): magnetizing and leakage inductances for transformers and phase inductances for shunt reactors. However, transients (high frequency phenomena) will boost the influence of the parasitic capacitances and require corresponding extension of their models. This paper analyzes the influence of the parasitic capacitances for a transformer (500 MVA, three-phase three-winding three-limb) and a shunt reactor (100 MVA) by building their models according to the datasheet followed by a comparison with the measurement of Sweep Frequency Response Analysis both on transformer and shunt reactor individually and on their combination.