Patent ID: 8598741

Claim:
A photovoltaic and fuel cell (PV-FC) hybrid generation system, the PV-FC hybrid generation system comprising: a DC/DC converter unit configured to convert an FC output voltage from a fuel cell into a preset voltage; a DC link unit directly connecting an output terminal of a photovoltaic cell and an output terminal of the DC/DC converter unit, and linking the converted FC output voltage from the DC/DC converter unit with a PV output voltage from the photovoltaic cell to generate a DC voltage; a DC/AC inverter unit configured to convert the DC voltage from the DC link unit into a preset AC voltage; a voltage/current detection unit configured to detect a voltage and a current generated by each of the fuel cell, the photovoltaic cell, and the DC/AC inverter unit; and a hybrid generation control unit configured to control operations of the DC/DC converter unit and the DC/AC inverter unit on the basis of the voltages and currents detected by the voltage/current detection unit, wherein the hybrid generation control unit comprises a converter controller configured to control an operation of the DC/DC converter unit by using a grid voltage from a grid of a commercial power supply, and the FC output voltage and current of the fuel cell, the converter controller comprises a first calculation part configured to calculate a first control error value for constant power control with respect to the DC/DC converter unit in the first grid-connected control mode, the first calculation part is configured to generate an FC current command value by dividing a preset FC power command value by the FC output voltage in each of the first grid-connected control mode, the second grid-connected control mode and a first standalone control mode, and calculate the first control error value corresponding to a difference value between the FC current command value and the FC current.