DC POWER SUPPLY SYSTEM

A DC power supply system includes: a natural energy power generator connected to a DC bus through a first DC-DC converter; a load device connected to the DC bus through a second DC-DC converter; a storage battery connected to the DC bus through a third DC-DC converter and configured to be charged with a generated power when the generated power is larger than a load power and to be discharged to supply power to the load device when the generated power is smaller than the load power; and a power management apparatus that manages operations of the first to third DC-DC converters based on current power generation amount and load power amount, prediction values for future power generation amount and load power amount, a remaining capacity of the storage battery, preset target values for respective blackout rate, battery lifetime, and power suppression rate, and the priorities among the target values.