Discussed are a power conversion apparatus and a photovoltaic module including the power conversion apparatus. The power conversion apparatus includes a converter unit to convert DC voltage from a solar cell module, the converter unit including a plurality of interleaving converters, and a controller to control the converter unit, wherein the controller changes switching periods of the interleaving converters and changes phase differences between the interleaving converters during operation sections of the interleaving converters, in response to a change of the switching periods of the interleaving converters. Consequently, it is possible to prevent instantaneous reduction of output power due to change of switching frequencies of the interleaving converters.