| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-withstand voltage IGBT element small in switching loss by reducing a transformer in size. <P>SOLUTION: The system has a PWM converter 31 which converts AC power fed by AC feeding to DC power via a transformer, and a motor drive inverter 21 which converts DC power obtained via the PWM converter 31 into AC power and controls the drive of permanent magnet motors 11 individually. A three-level PWM converter is applied to the PWM converter 31, and for the motor drive inverter 21, two DC parts are connected in series, and three DC-side terminals on the upper positive side of the two-serial DC part, at the serial junction of the two-serial DC part, and on the lower negative side of the two-serial DC part are connected to three terminals on the positive side, at the neutral point, and on the negative side of the three-level PWM converter. <P>COPYRIGHT: (C)2009,JPO&INPIT |
