Owing to the actual environmental impact

operational requirements and other factors

the structure of power system transmission lines is complex. In order to calculate the fault current of optical-fiber composite overhead ground wire (OPGW) in these cases

a generalized phase component method is proposed based on the split point of transmission lines

which splits the transmission line into several intervals according to the characteristics of each line. Each interval of the transmission line has the same electrical structure

and the equivalent impedance and voltage source of the interval terminal can be obtained by the multi-port Thevenin equivalent circuit. To solve each loop current

a unified model of generalized phase component in each interval is developed. Compared with the traditional model

the proposed one is more comprehensive considering the electromagnetic environment of the transmission lines

and is effective in solving the problem of the fault current of OPGW for transmission lines with complex structures.