| 摘要 |
<p>PURPOSE:To suppress the generation of the peak of an attracting force by precedingly rising a slip frequency prior to a voltage pattern at the time of thrust force rise, and precedingly falling a voltage pattern prior to the slip frequency at the time of thrust force fall. CONSTITUTION:When a power drive command 21 becomes ON, a primary delay calculator 28 applies a signal gradually rising to the set value of a current limiting value setter 22 according to a time constant tau to a slip frequency calculator 30. A voltage pattern is output through the change rate limiter 39 of a change time constant T1. In this case, tau<T1 is set. When the command 21 becomes OFF, the output of the calculator 28 falls to the minimum value fsmin at a gradient determined by the time constant tau. The pattern is multiplied by K (K<0), and reduced by the change rate determined by the time constant T1. In this case, T1<tau is set.</p> |
