A photovoltaic module, comprising: a solar cell module comprising a plurality of solar cells; and a junction box attached to a rear surface of the solar cell module, the junction box comprising a power conversion module to convert direct current voltage supplied from the solar cell module into alternating current voltage and to output the AC voltage, wherein the power conversion module comprises: at least one bypass diode (Da, Db, Dc) to receive the DC voltage from the solar cell module; a converter unit to power-convert the DC voltage from the at least one bypass diode, the converter unit comprising at least three interleaving converters; a capacitor coupled to receive voltage output from the converter unit; and an inverter unit to output the AC voltage using the voltage stored in the capacitor; a controller configured to control operations of the converter unit and the inverter unit, characterized in that the controller is configured to: change switching periods of the at least three interleaving converters and change phase differences between the at least three interleaving converters, after change of the switching periods of the at least three interleaving converters, wherein the at least three interleaving converters are operated in a critical conduction mode during changing switching periods of the at least three interleaving converters, wherein, in the CRM mode, the controller is configured to turn on the switching devices of the at least three interleaving converters when current flowing in the switching devices of the at least three interleaving converters or voltage applied to the switching devices is zero-crossed after the switching devices of the at least three interleaving converters are turned off, wherein when the switching periods of the at least three interleaving converters are increased the phase differences between the at least three interleaving converters are decreased, and wherein when the switching periods of the at least three interleaving converters are decreased, the phase differences between the at least three interleaving converters are increased. a solar cell module comprising a plurality of solar cells; and a junction box attached to a rear surface of the solar cell module, the junction box comprising a power conversion module to convert direct current voltage supplied from the solar cell module into alternating current voltage and to output the AC voltage, wherein the power conversion module comprises: at least one bypass diode (Da, Db, Dc) to receive the DC voltage from the solar cell module; a converter unit to power-convert the DC voltage from the at least one bypass diode, the converter unit comprising at least three interleaving converters; a capacitor coupled to receive voltage output from the converter unit; and an inverter unit to output the AC voltage using the voltage stored in the capacitor; at least one bypass diode (Da, Db, Dc) to receive the DC voltage from the solar cell module; a converter unit to power-convert the DC voltage from the at least one bypass diode, the converter unit comprising at least three interleaving converters; a capacitor coupled to receive voltage output from the converter unit; and an inverter unit to output the AC voltage using the voltage stored in the capacitor; a controller configured to control operations of the converter unit and the inverter unit, characterized in that the controller is configured to: change switching periods of the at least three interleaving converters and change phase differences between the at least three interleaving converters, after change of the switching periods of the at least three interleaving converters, wherein the at least three interleaving converters are operated in a critical conduction mode during changing switching periods of the at least three interleaving converters, wherein, in the CRM mode, the controller is configured to turn on the switching devices of the at least three interleaving converters when current flowing in the switching devices of the at least three interleaving converters or voltage applied to the switching devices is zero-crossed after the switching devices of the at least three interleaving converters are turned off, wherein when the switching periods of the at least three interleaving converters are increased the phase differences between the at least three interleaving converters are decreased, and wherein when the switching periods of the at least three interleaving converters are decreased, the phase differences between the at least three interleaving converters are increased. change switching periods of the at least three interleaving converters and change phase differences between the at least three interleaving converters, after change of the switching periods of the at least three interleaving converters, wherein the at least three interleaving converters are operated in a critical conduction mode during changing switching periods of the at least three interleaving converters, wherein, in the CRM mode, the controller is configured to turn on the switching devices of the at least three interleaving converters when current flowing in the switching devices of the at least three interleaving converters or voltage applied to the switching devices is zero-crossed after the switching devices of the at least three interleaving converters are turned off, wherein when the switching periods of the at least three interleaving converters are increased the phase differences between the at least three interleaving converters are decreased, and