| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for driving a rotary motor at an operating point of high efficiency depending on the torque, by changing a primary magnetic flux command value depending on the torque, in the primary magnetic flux control, thereby controlling the current phase appropriately.SOLUTION: For some torque T, an amplitude ia of an armature current is minimized when an amplitude Λδ of primary magnetic flux takes a value λδ0(T). At this time, maximum torque/current control is possible. The armature current is thereby determined automatically, by performing primary magnetic flux control by employing the value λδ0(T) in the amplitude of a primary magnetic flux command value. In other words, a current phase &bgr; is determined uniquely. Since the current phase &bgr; is controlled to a desired phase depending on the torque T, a rotary motor is driven at an operating point of high efficiency depending on the torque. |
