An adequate representation of the high-frequency behaviour of the power transformers
is essential for the appraisal of the surges transferred to the LV network. Models
differ remarkably and the desired compromise between accuracy and simplicity
depends on the specific application. Figure 12.6 shows the simplified model obtained
in References 18 and 19 for various three-phase, 13.8 kV–220/127 V, delta–earthed
wye connected distribution transformers. The parameters to represent each phase of