As an important power facility for railway

10 k V power distribution station and its fed power connection line provide power for each power supply equipment along the railway. In recent years

the power supply departments of various railway groups are continuously carryout out renovation of the substation and power connection in disrepair. During the reconstruction design of small capacity 10 kV distribution substation of certain railway group

it is found by the investigation that the reactive power compensation device of the substation has not been put into operation for many years. In view of the problem that the power factor of the distribution substation is generally high

the situation of the transformation of the distribution substation and its feeder lines in recent years is investigated

the characteristics of the power cable are described and the method to measure the power factor of the distribution substation is given. Then

the influence of capacitive charging power of cable on the power factor of distribution substation is analyzed theoretically. Finally

the powersupply system model is set up by Matlab Simulink module and the power factor values of different application number of cables at light load

medium load and heavy load are simulated. It is shown by the simulation test result that the massive use of cable is the main reason of high-power factor of distribution substation

which provides theoretical support for designers in designing similar transformation projects of distribution substations.