| 摘要 |
<p>PURPOSE: A decelerating unit and method of a sensorless BLDC(Brushless Direct Current) motor is provided to decelerate a rotation speed of a BLDC motor in operation of a required speed in a short time by repeating calculation of a rotation speed of the BLDC motor by detecting ZCP(Zero Crossing Point) of a reverse electromotive force after decelerating the BLDC motor in a calculated time period. CONSTITUTION: A speed control unit(110) generates a PWM(Pulse Width Modulation) signal and controls a rotation speed of a BLDC motor(100). A switching unit(120) generates a three-phase AC power by switching DC power according to a plurality of PWM signals. A plurality of potential dividers(130-1,130-2,130-3) divides a reverse electromotive force generated from the BLDC motor. A control unit calculates a current rotation speed of the BLDC motor using output signals from a plurality of the potential dividers. The control unit generates a plurality of PWM signals according to the current rotation speed and ordered rotation speed and outputs the signal to the switching unit. [Reference numerals] (110) Speed control unit; (130-1,130-2,130-3) Voltage divider; (AA) U phase; (BB) V phase; (CC) W phase</p> |
