| 摘要 |
PROBLEM TO BE SOLVED: To reduce torque ripples and speed irregularity due to the spatial harmonics in an alternating current motor. SOLUTION: A vector controller is provided with a first vector rotator 107 for converting the primary current of the alternating current motor 101 into the magnetization current and torque current of a rotation coordinate system having a prescribed phase angle, current regulators 104, 105 for regulating the magnetization current and torque current so that they coincide with a magnetization current instruction and a torque current instruction, a second vector rotator 106 output to convert the voltage instruction of the rotation coordinate system being their output into a stationary coordinate system, and a power converter 102 for performing power conversion in accordance with the voltage instruction output from the vector rotator 106. The vector controller is provided with a modulation signal generator 117 for generating a modulation signal having the frequency of the times of 6k (k: natural number) of the output frequency of the power converter 102 synchronizing in the phase angle, and a modulator 108 for modulating the magnetization current instruction and torque current instruction by the modulation signal. |
