| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotational frequency control arrangement which can appropriately perform rotational frequency feedback control by changing a calculation period. <P>SOLUTION: The rotational frequency control arrangement performs rotational frequency feedback control so that a rotor becomes a target rotational frequency based on a detection value of a rotational frequency sensor. A calculation period change means changes the calculation period of rotational frequency feedback control compared to a case when a rotational frequency is larger than a prescribed value if the rotational frequency becomes not more than the prescribed value. Namely, signal processing time of the rotational frequency sensor is prolonged when the rotational frequency drops, and the calculation period in rotational frequency feedback control is artificially extended. Thus, discontinuous change of a command value in rotational frequency feedback control can appropriately be suppressed when the rotational frequency drops. <P>COPYRIGHT: (C)2010,JPO&INPIT |
