In This case the network is 20kv. The broken delta is used to to detect the cut or damage of the neutral or the resistor and only used As an alarm.recently it is also implemented in the transformer Oscillography.
Another matter is that our 20kv transformers are really YNyn0 with the m.t star...
Hello again,
The transformer is a Delta-Wye with the neutral of the M.T side as I said grounded wiht a 13 ohms resistor. For a (22kv/squrt(3))/13=978 Amperes.This is the máximum current trhroug the resistor.
I know int a phase to ground fault there are capcitives thar run through the sane...
good morning from Spain.
In my zone the 15-20kv distribution system is grounded by a resistor that limits the earth current to 1000 or 300 amperes depending on the substation (cables or lines).
I'm analyzing an Oscillography of an earth to ground fault. In tis case the transformer has a 13...
I recently had a problem where a 51N protection saw a sawtooth oscilography (see attached file) and the main distance protecctión 21 didnt measure well beeing in a diferent winding.
In the subestation there where three windings for each phase two for protection and one for meassurement. Each...
