| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the following problem that arises when an alternating current signal is added to a q-axis current command to forcedly produce a high-frequency torque ripple in a variable-speed driving device for synchronous motors: when a voltage component becomes higher than the outputtable maximum voltage of an inverter, voltage saturation occurs and thus it is impossible to accurately generate a current command. <P>SOLUTION: An alternating current signal generator is caused to generate a d-axis high-frequency current command delayed by a phase of 90° from a q-axis high-frequency current command. This d-axis high-frequency current command is added to a d-axis current command and the result of this addition is input to a current control unit. When a synchronous motor is reversely rotated, this d-axis high-frequency current command is advanced by a phase of 90° from the q-axis high-frequency current command. <P>COPYRIGHT: (C)2009,JPO&INPIT |
