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.
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)