Grid-connected power conversion device

There is provided a grid-connected power conversion device including: one or more DC/DC converters connected to one or more renewable energy sources, respectively; a DC link unit whose voltage value is determined by the sum of currents output from the one or more DC/DC converters; and an inverter unit determining a current command value from the voltage value of the DC link unit, and generating an AC voltage according to the current command value. Since the respective DC/DC converters are available for the MPPT and the modulation index of the inverter are maximized, the efficiency may be improved. Also, since the modulation index can be maximized, a total harmonic distortion may be reduced. In addition, since the inverter can be operated according to the two-phase modulation scheme, harmonic and a switching loss may be reduced.