| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor control unit for a brushless motor that can achieve higher motor efficiency than before. <P>SOLUTION: A pulse width modulation (PWM) control circuit 1 in the brushless motor control unit is provided with: a rotation frequency detecting circuit 14 that detects a motor rotation frequency ω; a rotation frequency control circuit 11 that prepares a voltage amplitude command Va based on the deviation between the detected rotation frequency ω and a target rotation frequency ω*; a position calculating circuit 15 that derives a motor rotation angle θ; and a voltage command control circuit 12 that generates a voltage command signal V* based on the motor rotation angle θ, a phase lead angle ψ, and the voltage amplitude command Va. The voltage command control circuit 12 is provided with a phase lead angle deriving circuit 12a that, after deriving the phase lead angle ψo based on the motor rotation frequency ω, corrects the phase lead angle ψo based on the voltage amplitude command Va1 prepared when the brushless motor is in normal rotation and a voltage amplitude command Va2 prepared when the brushless motor is in reverse rotation, and derives the phase lead angle ψ. <P>COPYRIGHT: (C)2003,JPO |
