DIRECT-CURRENT POWER SUPPLY AND DISTRIBUTION SYSTEM

The present DC power supply and distribution system comprises: a plurality of power distribution lines each connected to a respective one of a plurality of loads; a first converter to receive an AC voltage from a commercial AC power source, convert the received AC voltage into a plurality of DC voltages and supply each of the plurality of DC voltages to a respective one of the plurality of power distribution lines; a second converter to receive a DC power from a power generating and/or storing source, convert the received DC power into a plurality of DC powers, and supply each of the plurality of DC powers to a respective one of the plurality of power distribution lines; and a controller to enhance the second converter in efficiency by controlling the first converter so that a ratio of the plurality of DC voltages is a predetermined first ratio.