| 摘要 |
PURPOSE:To design a terminal voltage of a motor as high as possible according to the withstand voltages of semiconductor devices, by controlling in a certain way an electric powder converter which feeds, a second DC voltage obtained through inputting a first DC voltage and converting it, to an inverter, and by controlling the second DC voltage with the electric power converter according to the withstand voltages of circuit parts. CONSTITUTION:A DC-DC converter 10 for converting a DC voltage to another DC voltage obtains a second DC voltage VDC2 by boosting a DC voltage VDC1 across both the ends of a first smoothing capacitor 3A. The second DC voltage VDC2 is stored in a second smoothing capacitor 3B. A control circuit 6 so controls an inverter 4 as to control a motor 5 according to a speed command 7, and in addition to this, inputs the voltage VDC2 across both the ends of the second smoothing capacitor 3B and so controls the electric power converter 10 as to keep the voltage VDC2 constant. Also, the output of the electric power converter 10, i.e., the input voltage to the inverter 4 is so controlled as to be high in the extent of the maximum voltage allowed according to the withstand voltages of semiconductor devices configuring the inverter 4. |
