A power conditioning system, comprising: a fuel cell configured to be connected to a load; a fuel cell converter connected between the fuel cell and the load, the fuel cell converter being configured to convert an output voltage of the fuel cell at a predetermined required voltage ratio; a battery connected in parallel with the fuel cell with respect to the load, the battery being configured to serve as a power supply source different from the fuel cell; a battery converter connected between the battery and the load, the battery converter being configured to convert an output voltage of the battery at a predetermined required voltage ratio; a voltage adjusting unit configured to adjust an output voltage of the battery converter to a predetermined voltage to generate a DC link voltage for synchronizing an output voltage of the fuel cell converter and the output voltage of the battery converter, wherein the battery converter has a plurality of phases, and each phase of the multi-phase battery converter includes a step-up switching element and a step-down switching element; and characterized by a ripple suppressing unit configured to include the step-up switching element of the battery converter of one phase and the step-down switching element of the battery converter of another phase; and the ripple suppressing unit being configured to set a duty ratio of each of the step-up switching element of the battery converter of the one phase and the step-down switching element of the battery converter of the other phase such that the sum of an ON-duty ratio of the step-up switching element of the battery converter of the one phase and an ON-duty ratio of the step-down switching element of the battery converter of the other phase is larger than the sum of the ON-duty ratio of the step-up switching element and the ON-duty ratio of the step-down switching element in each phase so as to suppress a ripple component of the DC link voltage in a situation where the DC link voltage is higher than the output voltage of the battery. a fuel cell configured to be connected to a load; a fuel cell converter connected between the fuel cell and the load, the fuel cell converter being configured to convert an output voltage of the fuel cell at a predetermined required voltage ratio; a battery connected in parallel with the fuel cell with respect to the load, the battery being configured to serve as a power supply source different from the fuel cell; a battery converter connected between the battery and the load, the battery converter being configured to convert an output voltage of the battery at a predetermined required voltage ratio; a voltage adjusting unit configured to adjust an output voltage of the battery converter to a predetermined voltage to generate a DC link voltage for synchronizing an output voltage of the fuel cell converter and the output voltage of the battery converter, wherein the battery converter has a plurality of phases, and each phase of the multi-phase battery converter includes a step-up switching element and a step-down switching element; and characterized by a ripple suppressing unit configured to include the step-up switching element of the battery converter of one phase and the step-down switching element of the battery converter of another phase; and the ripple suppressing unit being configured to set a duty ratio of each of the step-up switching element of the battery converter of the one phase and the step-down switching element of the battery converter of the other phase such that the sum of an ON-duty ratio of the step-up switching element of the battery converter of the one phase and an ON-duty ratio of the step-down switching element of the battery converter of the other phase is larger than the sum of the ON-duty ratio of the step-up switching element and the ON-duty ratio of the step-down switching element in each phase so as to suppress a ripple component of the DC link voltage in a situation where the DC link voltage is higher than the output voltage of the battery.