Battery control circuit for power generation system using renewable energy

A battery control circuit for a power generation system using renewable energy, the circuit comprising:

• a flow battery that is charged with direct current (DC) electric energy or discharges charged DC electric energy;
• a DC power supply unit that has an anode and a cathode, and supplies the DC electric energy to the flow battery;
• a first DC-DC converter that connected between the DC power supply unit and the flow battery, and the first DC-DC converter has a switching element providing current flow paths in two directions, the two directions including a first direction of supplying the DC electric energy from the DC power supply unit to the flow battery, and a second direction of discharging the DC electric energy charged in the flow battery to a ground;
• a first capacitor that is connected in series to the flow battery, the first capacitor fully discharging the flow battery in a manner that the sum of a voltage across the first capacitor and a voltage across the flow battery becomes higher than an output voltage of the first DC-DC converter when fully discharging the flow battery;
• a second DC-DC converter that is connected between the DC power supply unit and the first capacitor, and has a switching element switched to a position of supplying the DC electric energy from the DC power supply unit to the first capacitor such that the first capacitor is charged;
• and
• a controller that controls the first DC-DC converter and the second DC-DC converter, the controller controlling the switching element of the first DC-DC converter to form the current flow path in the second direction when a number of times of charging and discharging the flow battery reaches a preset number of times.