PURPOSE: To save the system installation cost by stepping down, in a matching transformer, the rated voltage of section cable system to the rated voltage in the stator section.

CONSTITUTION: The section cable systems(SS) 5 to 10 receive the power supply from only one converter. Therefore, a power station interval corresponding to 2d which is two times the train interval is generated. The converter 11 is located within the sub-stations 21 to 26. In the substations 21 to 26, a high voltage of the EVU circuit network is first transformed to an intermediate voltage. In the converter 11, a system having the variable frequency and amplitude is generated and subsequently the voltage is converted to the high voltage. Moreover, a matching transformer 32 is connected between the SS 5 to 10 and stator sections 1, 2 and the voltage is dropped to the rated voltage. SS 6, 7 or 8, 9 are mutually connected with a coupling switch 33 or 34. As a result, when a fault occurs only within one sub-station, SS receiving the influence of the fault receives the power supply from the substation of the adjacent SS.