In view of the background that most of the existing 500 kV/220 kV power grid partition methods are achieved by disconnecting certain circuits with little

if any

quantitative research on 500 kV/220 kV grid partition structure as a whole reported. A method of changing the power structure to predict the short-circuit current by solving the fractal dimension of the geographical wiring diagram is proposed. A quantitative research on the fractal dimension of a 500 kV/220 kV power grid structure is presented using the box dimension programmed by MATLAB calculations program while the short-circuit current basic model is studied

based on which the mathematical relation between power structure and short-circuit current is developed and the prediction of short-circuit current is achieved. Finally

an application example is given to prove the effectiveness of the proposed method. This work is supported by National Natural Science Foundation of China (No. 51307104).