| 摘要 |
PURPOSE: To realize weak magnetic-field control without calculating a complex d-axis current command or carrying out temperature compensation in a motor constant. CONSTITUTION: A driving unit includes a voltage-type inverter 2 for driving a permanent magnet-type synchronous motor 4, a three-phase/two-phase converter 701 for calculating a d-axis current detection value and a q-axis current detection value in coordinate conversion from a stator current detection value in the synchronous motor 4, a DC current control system constituted by an adder, an adjuster and the like for making these current detection values near to the d-axis current command value or q-axis current command value under control, and a control circuit 7A for carrying out weak field control through the d-axis current carried in a negative direction. In addition, a proportional adjuster 706A is provided as a DC current control system, and while d-axis current command value is limited to zero, weak field control is carried out. |
