A power conversion apparatus comprising: a first input terminal; a second input terminal to which a potential lower than a potential of said first input terminal is applied; an output terminal (Pu, Pv, Pw); a power converter including an upper switching element (S1 to S3) connected between said first input terminal and said output terminal, and a lower switching element (S4 to S6) connected between said second input terminal and said output terminal; a switching control unit that controls said upper switching element (S1 to S3) and said lower switching element (S4 to S6) based upon a comparison between a voltage command value (V**) for an output voltage outputted from said power converter and a carrier having a predetermined periodic time; and characterized by a carrier generating unit that gives said carrier monotonically decreasing to said switching control unit during either one of a first period that is a period immediately following a period in which said voltage command value (V**) is a value not more than a minimum value of said carrier, said voltage command value (V**) taking a first predetermined value larger than the minimum value of said carrier in the first period, and a second period that is a period immediately preceding a period in which said voltage command value (V**) is not less than a maximum value of said carrier, said voltage command value (V**) taking a second predetermined value smaller than said maximum value in the second period, said first period and second period having said predetermined periodic time, and that gives said carrier monotonically increasing to said switching control unit during either one of a third period that is a period immediately following a period in which said voltage command value (V**) is a value not less than said maximum value, said voltage command value (V**) taking a third predetermined value smaller than said maximum value in the third period, and a fourth period that is a period immediately preceding a period in which said voltage command value (V**) is not more than said minimum value, said voltage command value (V**) taking a fourth predetermined value larger than said minimum value in the fourth period, said third period and fourth period having said predetermined periodic time. a first input terminal; a second input terminal to which a potential lower than a potential of said first input terminal is applied; an output terminal (Pu, Pv, Pw); a power converter including an upper switching element (S1 to S3) connected between said first input terminal and said output terminal, and a lower switching element (S4 to S6) connected between said second input terminal and said output terminal; a switching control unit that controls said upper switching element (S1 to S3) and said lower switching element (S4 to S6) based upon a comparison between a voltage command value (V**) for an output voltage outputted from said power converter and a carrier having a predetermined periodic time; and characterized by a carrier generating unit that gives said carrier monotonically decreasing to said switching control unit during either one of a first period that is a period immediately following a period in which said voltage command value (V**) is a value not more than a minimum value of said carrier, said voltage command value (V**) taking a first predetermined value larger than the minimum value of said carrier in the first period, and a second period that is a period immediately preceding a period in which said voltage command value (V**) is not less than a maximum value of said carrier, said voltage command value (V**) taking a second predetermined value smaller than said maximum value in the second period, said first period and second period having said predetermined periodic time, and that gives said carrier monotonically increasing to said switching control unit during either one of a third period that is a period immediately following a period in which said voltage command value (V**) is a value not less than said maximum value, said voltage command value (V**) taking a third predetermined value smaller than said maximum value in the third period, and a fourth period that is a period immediately preceding a period in which said voltage command value (V**) is not more than said minimum value, said voltage command value (V**) taking a fourth predetermined value larger than said minimum value in the fourth period, said third period and fourth period having said predetermined periodic time.