| 摘要 |
PROBLEM TO BE SOLVED: To enable preventing cogging by applying a smoothing current which has frequency equal to the first multiple of a fundamental frequency, amplitude- canceling torque disturbances in the second multiple of the fundamental frequency and phase shift with respect to a drive current, to an electromagnet. SOLUTION: Three most important smoothing currents are a smoothing current IS1 exsisting in zero-fold fundamental frequency, a smoothing current IS2 having the same frequency as a drive current, and a smoothing current IS3 having a frequency equal to three times the fundamental frequency. These are added or superposed and applied to a wire 20 of a motor. A half-phase current IB corresponding to the applied current is applied to another electromagnet of the motor. The smoothing current has a specified phase shift and amplitude with respect to a drive current IA. Generally, the amplitude and the phase shift of the current IS2 correspond to a torque disturbance generated by a frequency equal to twice the frequency of the drive current IA. The phase shift and the amplitude of the current IS3 correspond to a torque disturbance generated by a frequency equal to four times the frequency of the drive current. |
