Q.Insulation of a 220 kV and 50 Hz high voltage transformer is shown below. Where, d;"1 mm. " 3.1(oil impregnated paper). Est 60 kV/cm: d-5 mm. -2.2 (transformer oil). E-100kV/cmd-2 mm 4.2 (tough paper). Ess-30 kV/cm LV winding 23 HV winding 6-12 mm a) If the applied voltage is U-220 KV. calculate voltages and electric field across in each dielectric layer? Evaluate the system from the point of discharge phenomena? b) Find the maximum voltage that can be applied to the system without discharge at any of the insulating materials c) If the place of the tough paper is filled by transformer oil (2.2) find the voltages and electric field across in each dielectric layer? Evaluate the system from the point of discharge phenomena? If the results are compared with part (a), which insulation is better?