some factors can cause CT saturation, like high connected burden, fault current value, and DC offset, fault angle inception, remanence/residual flux.
for numerical relays, normally relay manufacturers are giving CT requirements for their relays.
three winding transformer with following parameters,
- 132/11/11 kV (both the 11 kV windings are loaded).
- 120/60/60 MVA
- YN yn0 yn0
1- what is the recommended/practical Z% between HV-LV1 , HV-LV2 , and LV1-LV2 ? to limit the short circuit to 15 kA.
2- is there is a requirement for NER for...
Greetings,
for 33 kV OHL steel lattice tower, and for designing the structure, the working loads (for normal condition, and broken wire condition) shall be multiplied by a factor of safety (=2 for NC, and =1.5 for BWC).
now incase of BWC all loadings (for intact and broken wires) shall be...
for 33 kV double circuit OHL lattice steel towers, what is the criteria for selecting the back to back distance (distance between tower legs).
is it related to tower height, or tower slop ?.
any reference for the above.
for 33 kV double circuit OHL lattice steel towers, what is the criteria for selecting the back to back distance (distance between tower legs).
is it related to tower height, or tower slop ?.
any reference for the above.
How to calculate the electromagnetic interference generated from a 132kV single core (in trefoil formation) power cable, need to be calculated for diffrent distances, like 1m, 2m,5m.
1500 kVA transformer, 11/0.4 kV Dyn11 installed in a substation
what is the standard or practice for earthing the LV side neutral point ?
is it required that the neutral point should have a separate earthing point/system or it can be connected with the substation earthing system?
what is the...
0n 415 V TT earthed system, Can we use Residual Current Device (RCD) at load side.
I'm having a case where RCD is tripping when we supply from portable generator with unearthed neutral, but not tripping when we supply from a transformer with earthed neutral.
For battery sizing, can we convert a load (A) for 150ms to equivalent load for 1 sec, as a percentage value
e.g. 180 A for 150ms is equivalent to (150ms / 1000 ms) X 180 = 27 A for 1 sec (1000 ms)
This is required as the minimum time duration which we can use in battery sizing software is 1 sec.
For a Dyn transformer, is the following correct:
- 3 phase at delta side to be shorted together.
- 3 phase at y side to be shorted together.
- apply the voltage between one of the phases at y side and nutral.
- Z0 will be equall to V/I
