摘要 |
<P>PROBLEM TO BE SOLVED: To provide a means in a brushless motor sensorless drive system, by which a rotational state before starting is detected to determine a proper starting method, exact reverse brake control is achieved when a reverse rotational state is detected, and a braking stopping state is detected from the reverse rotational state to be succeeded to the smoothed normal rotational acceleration. <P>SOLUTION: Based on a method in which a reverse electromotive voltage at a position giving a direct commutation timing is detected to perform commutation control, rotor rotational states before starting are detected to determine optimal starting methods respectively, and continuous commutation control is achieved which continues from the reverse rotation to braking, stopping and further to normal rotation using the means by which the reverse electromotive voltage at low speed of the reverse rotation is significantly amplified to enhance the measurement sensitivity of a rotor position from the reverse brake of the rotor to its stop. <P>COPYRIGHT: (C)2011,JPO&INPIT |