| 摘要 |
PURPOSE:To eliminate voltage fluctuation by arranging two series multiple inverters having common neutral point in parallel and setting the phase difference of output voltage to 60 deg.. CONSTITUTION:Series multiple inverters 1, 2 converts DC voltage into three level AC voltage having positive, zero and negative levels and feeds three-phase AC voltage to an AC motor 3. Switching elements in the inverters 1, 2 are applied with ON/OFF pulses from PWM pulses operating units 4, 5. A voltage command operating unit 6 operates a voltage command in a rotary field coordinate system, then the voltage command is fed to a coordinate converter 7 in order to produce a three-phase AC voltage command in a stator coordinate system and a three-phase AC voltage command having 60 deg. lagged phase which are fed to the operating unit 4, 5. |
