| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent stepping out of a motor in an electric fluid pump arrangement, using a brushless DC motor which is driven using a sensorless drive circuit. <P>SOLUTION: The electric fluid pump arrangement is provided with a controller, which drives the brushless DC motor by current feedback control and switches the current feedback control to number of revolutions control, when the number of revolutions of the motor is lowered to a predetermined value or smaller. Thus, if the number of revolutions of the motor is greater than the predetermined value, the motor is subjected to current feedback control. If load fluctuation is caused due to the influence of foreign matter or the like and the motor voltage is reduced due to the influence of current feedback control and thus the number of revolutions is lowered, motor control is switched to control of the number of revolutions. <P>COPYRIGHT: (C)2004,JPO |
