A power conversion apparatus comprising: a converter unit configured to receive a direct current, DC, voltage from a solar cell module, convert the direct current, DC, voltage from the solar cell module, into alternating current, AC, voltage, the converter unit comprising a plurality of interleaving converters, and the plurality of interleaving converters comprises a switching device, respectively; and a controller configured to control the converter unit, wherein the controller is configured to change switching frequencies of the switching devices of the interleaving converters and characterized in that the controller is further configured to change phase differences between the interleaving converters during turn-on sections of the switching devices of the interleaving converters, in response to a change of the switching frequencies of the interleaving converters, wherein, when the switching frequencies of the interleaving converters are decreased, the controller is configured to increase an overlapping region between the turn-on sections of the switching devices of the interleaving converters, such that the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, are less than the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, before the decrease of the switching frequencies of the interleaving converters, and that the controller is configured to change the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, such that the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters are sequentially approximate to a reference phase difference after the change of the switching frequencies of the interleaving converters. a converter unit configured to receive a direct current, DC, voltage from a solar cell module, convert the direct current, DC, voltage from the solar cell module, into alternating current, AC, voltage, the converter unit comprising a plurality of interleaving converters, and the plurality of interleaving converters comprises a switching device, respectively; and a controller configured to control the converter unit, wherein the controller is configured to change switching frequencies of the switching devices of the interleaving converters and characterized in that the controller is further configured to change phase differences between the interleaving converters during turn-on sections of the switching devices of the interleaving converters, in response to a change of the switching frequencies of the interleaving converters, wherein, when the switching frequencies of the interleaving converters are decreased, the controller is configured to increase an overlapping region between the turn-on sections of the switching devices of the interleaving converters, such that the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, are less than the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, before the decrease of the switching frequencies of the interleaving converters, and that the controller is configured to change the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters, such that the phase differences between the interleaving converters during the turn-on sections of the switching devices of the interleaving converters are sequentially approximate to a reference phase difference after the change of the switching frequencies of the interleaving converters.