| 摘要 |
PURPOSE:To reduce a waveform distortion by variably setting a carrier frequency higher than that of a waveform reference for instructing the value of an AC output depending on a dead time set at an inverter and an allowable ratio of the pulse width. CONSTITUTION:An output waveform reference V' is generated by a generator 7 according to an electric angle reference theta obtained by integrating a frequency reference (f) and the amplitude A of an output voltage. A carrier command generator 9 generates a carrier command value lc from a set dead time td, a carrier frequency set value fc previously set to a lower limit value or higher of the carrier frequency and a waveform reference V*, etc., input to a carrier generator 8 to generate a carrier signal ls. A signal generator 5 compares the reference V' with the signal ls, and applies a PWM command to an inverter 3. Thus, the carrier frequency considered for the dead time is set, and an output waveform distortion due to the dead time, a torque ripple are alleviated. |
