DC power supply system

A DC power supply system comprising:

• a DC bus serving as a bus bar for DC power supply;
• a natural energy power generator that supplies generated power to the DC bus;
• a plurality of storage batteries that store the generated power from the natural energy power generator;
• a plurality of bidirectional DC-DC converters that connect the plurality of corresponding storage batteries to the DC bus, the plurality of bidirectional DC-DC converters including a first bidirectional DC-DC converter and a second bidirectional DC-DC converter;
• a power management apparatus that manages operations of the plurality of bidirectional DC-DC converters;
• and
• a target voltage correction circuit that i) calculates a first correction value of a target value for a first output voltage of the first bi-directional DC-DC converter from a first average value of a plurality of first actual measurement values taken at different times of the first output voltage of the first bidirectional DC-DC converter and ii) calculates a second correction value of the target value for a second output voltage of the second bidirectional DC-DC converter from a second average value of a plurality of second actual measurement values taken at different times of the second output voltage of the second bidirectional DC-DC converter,
• wherein the power management apparatus individually controls each output voltage of the bidirectional DC-DC converters by using each target value of the output voltages corrected based on the correction values such that the power management apparatus controls i) the first output voltage of the first bidirectional DC-DC converter using the first output voltage corrected based on the calculated first correction value and ii) the second output voltage of the second bidirectional DC-DC converter using the second output voltage corrected based on the calculated second correction value.