| 摘要 |
PURPOSE:To realize smooth rotation by predicting cogging torque generating conditions based on the number of poles of a motor, characteristic parameters and pulses fed from an absolute value encoder thereby correcting a torque command so that torque ripple is canceled. CONSTITUTION:Cogging torque of a synchronous motor is predicted to be generated as shown by a curve (b), a correction torque (d) as shown on a dot curve for canceling the cogging torque is fed to a torque correcting means 1 as the coefficient (a) which is added, at an operating point 4, to a torque command fed from the output stage of a primary lag amplifying circuit 3. In the embodiment, a synchronous motor provided with a three-phase absolute value encoder 8 is the objective motor. The coefficient (a) is set according to a formula a = TK-Sin(x+90 deg.)XTK after (x) representing the number of pulses PT per single period of cogging torque is determined according to a formula x = CNTX360 deg./>>ECPNX4/PR1X3. |
