| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor controller which is constituted to appropriately control the generation of a PWM signal by two-phase modulation, and to restrict rises in temperature of a switching element and an inverter as much as possible. <P>SOLUTION: During the rotating speed of a motor is judged to be a predetermined value or more by a rotating speed detecting means 5, a modulation system setting means 10 switches to an upper stage reflux type two-phase modulation system, when an absolute value is highest and a voltage command value is in a positive range. The setting means switches to a lower stage reflux type two-phase modulation system, when the absolute value is highest and the voltage command value is in a negative range, of voltage command values corresponding to a first phase to a third phase of the motor. Moreover, during the rotating speed of the motor is judged to be less than the predetermined value by the rotating speed detecting means 5, the setting means switches between the upper stage reflux type two-phase modulation system and the lower stage reflux type two-phase modulation system, every when a lapse of predetermined time is judged by a timer detecting means 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
