| 摘要 |
PURPOSE:To increase the stability of a motor at the time of its stop and to contrive to improve a gain by reducing a slip frequency to zero immediately at the time of stopping the motor through performing a slip frequency control by software. CONSTITUTION:A difference between a velocity command Vc and a real velocity omegar detected by a speed detector 7 becomes a torque command via an amplifier 1, and a secondary current command means 2 calculates a secondary current command value from the torque command and the output of an exciting flux command means 8. A primary current arithmetic operation circuit 3 calculates a primary current command value from the secondary current command value and an exciting current component. The command value is converted into a three-phase component by a three-phase converter 4 and controls a motor 6 via a current control 5. When the calculation of the slip frequency fs(omegas) and an exciting frequency omega0 surrounded by a broken line 12 is performed by software processing, it is possible to raise the accuracy of the calculation and to reduce the slip frequency to zero immediately at the time of stopping a motor. |
