| 摘要 |
PURPOSE: To suppress vibration and noise caused by fluctuation in the speed by estimating the pole position of a rotor correctly and performing the commutation at an accurate timing without stopping a motor thereby suppressing fluctuation in the speed during single revolution of the motor. CONSTITUTION: A voltage induced in a motor is fed to an A/D converter and the terminal voltage of each winding is detected every ON interval of PWM, as effective induced voltage information of stator winding, at a control section. Variation rate of the terminal voltage with time is then determined and extrapolated to estimate a commutation timing. In this regard, number of detection times of voltage induced during Tpwm (PWM period) is altered depending on the duty factor of PWM and the commutation time is estimated every time when the induced voltage is detected thus controlling the driving of motor through driver and inverter circuits. |
