PURPOSE: To reduce element groups, over-voltage protective circuits, and snubber circuits of thyrister rectifiers by constituting so as to jointly use negative pole side thyrister groups and a power supply side transformer in an individual power supply type load dispatching system.

CONSTITUTION: The AC electric power which is input through a common transformer 1 is converted into a DC current by positive pole side thyrister groups 2-5, and is fed to individual feeders, then is returned to the commercial frequency power supply side through common negative pole side thyristers 6. If a short circuit accident occurs, the accident current rises rapidly, therefore, the thyrister rectifier element groups are gate shifted by the signals of protective relays 70W 100, being operated temporarily in the inverter region, then they are gate blocked and stopped, concurrently cutting off the failed circuit. If a voltage unbalance occurs between individual load circuits, a circulating current flows from a high potential side through stopper diodes 11, a DC line breaker 12, and stopper didoes 13 to a low potential side, thereby the unbalance is suppressed because of power dissipation by cars at the low potential side load.