| 摘要 |
PROBLEM TO BE SOLVED: To reduce distortion of an AC output or input waveform caused by low order harmonies of a power converter. SOLUTION: The controller 7 for a power converter comprises a correction signal generator 38 outputting a correction signal S becoming an symmetric wave for the AC output or input frequency. Saw-tooth carrier h of a carrier generator 9 is corrected by the correction signal S into a correction carrier h1 symmetric for the AC output or input frequency and a PWM signal U being outputted from a comparator 10 is corrected by the correction carrier h1, Since the PWM signal U is corrected into a symmetric wave for the AC output or input frequency and a low even order harmonic is not contained in the corrected PWM signal U1, distortion of an AC output or input waveform caused by low order harmonics can be reduced. |
