| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain a rise in losses due to an increase in current and, while so doing, realize smooth switching of control modes from pulse width modulation to rectangular wave control. <P>SOLUTION: A control mode determination unit 16, which is used to determine switching of control modes employed by a switching control unit 14 on the basis of a prescribed reference modulation rate MR which is lower than a modulation rate adopted during execution of rectangular wave control, determines switching from pulse width modulation control to rectangular wave control on condition that an actual modulation rate MI is equal to or greater than the modulation rate MR, and that a revolution speed ω of a rotary electric machine is equal to or greater than a prescribed rectangular wave transition resolution speed. A weak field current command determination unit 12 determines a weak field current command ΔId according to a difference between a modulation rate command M fixed to the reference modulation rate MR and the actual modulation rate MI. The rectangular wave transition resolution speed is set to a value which differs depending on at least a DC voltage Vdc. <P>COPYRIGHT: (C)2013,JPO&INPIT |
