| 摘要 |
PURPOSE:To suppress torque pulsation produced in acceleration or deceleration and to improve the accelerating and decelerating characteristics, by setting up the instantaneous value current of each phase as a command current when a motor is at a rotating speed based on its speed command value depending on the speed deviation. CONSTITUTION:A command current setting circuit 21 is composed of a subtractor 21a, a slip frequency setter 21b and a command current operation section 21c. The subtractor 21a finds the deviation between a rotating command value f'm from a rotating speed setter 22 and a rotating speed fm from a rotating speed detector 5, i.e. the deviation of the rotating speed fm (f'm-fm). The slip frequency setter 21b sets a slip frequency fs based on the deviation fm. With the command current operation section 21c based on the slip frequency fs and rotating speed fm the instantaneous currents for two phases ia and ib are found by operation. |
