I need informtion regarding the time and sequency for power transformer, 150 MVA 220 kV, energizing. I read about keeping the transformer about 72 hours no load before energizing. Is there some standards about this subject?
Is anyone who can indicate me the level of induce voltage for power transformer which have to be tested according to GOST. Is it possible accoring to GOST that the level of induced voltage, on LV side, to be bigger than 2xUn?
What is the number of GOST which give this indication.
For power transformer with no load tap changer +/- 10% of HV voltage, liniar; the value of overvoltage which apear on tapped winding is too high. What kind a protection for tapped windings it is necessary to use?
I have to make a project for 150 MVA 220/115 kV autotransformer and the customer ask for:-protection of the tertiary windings from overvoltage stresses by means of "NEPTUNE connection" of suitably design surge arresters.-What does it means? How I can solve the requirements?
