A power conversion device, which outputs an alternating current voltage corresponding to an output voltage command (V*), comprising: a direct current power source which outputs a three-level voltage (Vp, Vn); an alternating current power source , one end of which is connected to an intermediate potential point of the direct current power source ; an inverter which selects and outputs either the three-level voltage (Vp, Vn)of the direct current power source or the voltage (Vr) of the alternating current power source ; a reactor (Lf) which smooths the output voltage of the inverter , and a control section which controls the inverter in accordance with the output voltage command (V*), wherein the control section commands a carrier signal (Sc) of a first frequency (f1) when on a first condition that the voltage (Vr) of the alternating current power source is smaller than the output voltage command (V*), and that the difference between the output voltage command (V*) and the voltage (Vr) of the alternating current power source is smaller than a predetermined value, commands a carrier signal (Sc) of a second frequency (f2) higher than the first frequency (f1) when on a second condition that the voltage (Vr) of the alternating current power source is smaller than the output voltage command (V*), and that the difference between the output voltage command (V*) and the voltage (Vr) of the alternating current power source is larger than the predetermined value, and generates a control signal (G1, G2, Gs1, Gs2) based on the output voltage command (V*) and on the commanded carrier signal (Sc), and that the inverter , in accordance with the control signal(G1, G2, Gs1, Gs2), outputs an alternating current voltage corresponding to the output voltage command (V*). a direct current power source which outputs a three-level voltage (Vp, Vn); an alternating current power source , one end of which is connected to an intermediate potential point of the direct current power source ; an inverter which selects and outputs either the three-level voltage (Vp, Vn)of the direct current power source or the voltage (Vr) of the alternating current power source ; a reactor (Lf) which smooths the output voltage of the inverter , and a control section which controls the inverter in accordance with the output voltage command (V*), wherein the control section commands a carrier signal (Sc) of a first frequency (f1) when on a first condition that the voltage (Vr) of the alternating current power source is smaller than the output voltage command (V*), and that the difference between the output voltage command (V*) and the voltage (Vr) of the alternating current power source is smaller than a predetermined value, commands a carrier signal (Sc) of a second frequency (f2) higher than the first frequency (f1) when on a second condition that the voltage (Vr) of the alternating current power source is smaller than the output voltage command (V*), and that the difference between the output voltage command (V*) and the voltage (Vr) of the alternating current power source is larger than the predetermined value, and generates a control signal (G1, G2, Gs1, Gs2) based on the output voltage command (V*) and on the commanded carrier signal (Sc), and that the inverter , in accordance with the control signal(G1, G2, Gs1, Gs2), outputs an alternating current voltage corresponding to the output voltage command (V*). <EOS>