| 摘要 |
A power conversion device includes a converter-inverter controller 6 for controlling a converter 1 and an inverter 3. The power conversion device further includes a DC capacitor 4 connected between the converter 1 and the inverter 3 and a DC capacitor voltage detector 5 for detecting a DC capacitor voltage Efc between the connection ends of the DC capacitor 4. The converter-inverter controller 6 provides variable control on the DC capacitor voltage Efc to the converter 1 on the basis of the motor frequency of an AC motor 2, the DC capacitor voltage Efc, and a pulse mode. Within a predetermined range of motor frequencies, the converter-inverter controller 6 fixes the PWM modulation factor of the inverter 3 to a value m0 and provides operation control to the inverter 3, where the value m0 being to reduce a harmonic of a predetermined order included in the output voltage from the inverter 3. |
