In FDLF method,
B' corresponds to susceptance of unknown of PQ and PV bus
Order of B' matrix is = (n -1)*(n - 1)
Where n is total no. of buses.
Order of B'' = (n - m - 1)*(n - m - 1)
A form of AC testing that applies voltage and measures the leakage/loss current of electrical insulation.
It is a type of insulation testing used to evaluate the integrity of electrical insulation.
The ratio of full load current to short circuit current = 1/5
Xsc = j/(1/5)
External reactance required = j*((1/5) - 0.05))
= j*0.15 pu
Full load current = (30*1000)/(√3*11)
= 1574.6 A
Per unit reactance = j*0.15 = (I*Xr)/V
j*0.15 = (1574.6*Xb)/((11/√3)*1000))
= 0.60 ohm
In bias differential protection for transformer,
There are two basic settings required to setup the percentage biased differential protection.
1. Minimum pickup
2. The slope.
The minimum pick-up covers the transformer magnetizing current typically 1-4% of transformer rating.
A pick up of 0.2 to 0.3 times the TAP is recommended for general cases.
The slope is defined by determining the potential sources of differential current.