| 摘要 |
PROBLEM TO BE SOLVED: To improve a current distortion factor while reducing a switching loss, in a power conversion device in hysteresis control.SOLUTION: Phases of the respective phases at a three-phase AC side are detected. During a three-phase modulation period in which a phase of any one phase is in a predetermined period including &pgr;/2 rad and in a predetermined period including 3&pgr;/2 rad, hysteresis control is performed by three-phase modulation. For each phase, during a period other than a three-phase modulation period and during a period in which the phase is from &pgr;/6 rad to 2&pgr;/6 rad and from 4&pgr;/6 rad to 5&pgr;/6 rad, two-phase modulation of turning on a switching element connected with a positive side of an arm of the phase, and turning off a switching element connected with a negative side. During a period other than the three-phase modulation period and during a period in which the phase is from 7&pgr;/6 rad to 8&pgr;/6 rad and from 10&pgr;/6 rad to 11&pgr;/6 rad, two-phase modulation of turning on the switching element connected with the negative side of the arm of the phase and turning off the switching element connected with the positive side is performed. |
