| 摘要 |
In a state of synchronous operation in which a voltage and a frequency of an inverter output are increased in a stage of starting, when it is decided that a voltage difference signal is not at a specified level by a voltage difference signal level deciding section (41) or when a comparison result in a mode comparing section (42) signifies that a position signal and an inverter mode do not have a specified relation, a V/F pattern setting section (44) outputs a voltage command signal for lowering the inverter output voltage to a PWM section (54). Meanwhile, when it is decided that the voltage difference signal is at the specified level by the voltage difference signal level deciding section (41) and when the position signal and the inverter mode have the specified relation upon receiving a decision signal from the voltage difference signal level deciding section (41) and a signal representing the comparison result from the mode comparing section (42), a position sensing operation switching section (43) switches an operation switching switch SW from a synchronous operation side to a position sensing operation side. <IMAGE> |
