Intern turn winding fault can be easily detect by differential protection relay. Also detect by buchholz relay (gas operated relay), cause buchholz relay is used to detect the internal fault of transformer.
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)
Power factor for purely inductive circuit is 0 and power factor angle is 90 degree. Power factor for purely capacitive circuit is 0 and power factor angle is 90 degree Power factor for purely resistive circuit is 1 and power factor angle is 0 degree
For lagging power factor = (IR*cosφ + Ixsinφ)/Vr For leading power factor = (IR*cosφ - Ixsinφ)/Vr Zero voltage regulation occurs on leading power factor only.