IN-MOTION POWER SUPPLY SYSTEM

A period for performing pre-power-supply check prior to main power supply from a power supply device (100) to a power reception device (200) is provided and, a power-receiving-side controller (220) is configured to: check a supplied electric power supplied from the power supply device (100) to the power reception device (200), in a state where an effective value of an output voltage of a inverter circuit (32) is fixed to a predetermined first voltage by the power-supply-side controller (16) and an input voltage of the DC-DC converter (238) is fixed to a predetermined second voltage by the power-receiving-side controller, in the pre-power-supply check, and cause, in response to the supplied electric power being equal to a predetermined electric power or more, the power supply device (100) to start the main power supply.