A power conversion apparatus includes M first slots, wherein each of M first slots is electrically connected to an input side of one of N first bus bars, and a respective first slot of the M first slots is electrically connected to a first module that can supply an alternating current or a direct current to the first bus bar electrically connected to the first slot. The apparatus further includes P second slots, wherein each of the P second slots is electrically connected between an output side of one of the N first bus bars and an input side of one of second bus bars, and a respective second slot of the P second slots is electrically connected to a second module that converts an alternating current into a direct current or that converts a direct current into a direct current.