Design and Manufacture of Sensorless Drive Circuit for Brushless DC Motor

• Main Authors: Chia-Lin Wu, 吳嘉霖
• Other Authors: Yi-Hua Fan
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/06069640958111852159

碩士 === 中原大學 === 機械工程研究所 === 93 === Abstract Brushless DC motors are receiving much attention for drive application because of their high efficiency and high torque. BLDC motors can rotate in high speed and increase reliability of the system because they are without brush and commutator. Generally the drive for the BLDC motor requires a position sensor for providing proper commutaion sequence to turn on motor smoothly. But the sensor increases the cost and size of the motor, and it will reduce the robustness of system. So it becomes important in how to drive motors without sensors. This study is dedicated to design sensorless drivers of the BLDC motor. The drivers are combined digital signal processor (DSP) with peripheral circuits, which include power system, drive and protect circuits. The chip TMP88CS42 that is produced by TOSHIBA contain programmable motor driver. And it is easier for us to drive motor. When the motor is driven by 120° conduction, the current flows in only two phase at any time, leaves the third motor terminal floating. The zero crossing of back EMF of the floating phase can be detected to determine the commutation sequence without Hall sensors. According to compare signal of sensorless circuit with signal of Hall sensor, it proves that the sensorless drivers of the BLDC motor can be in place of Hall sensor, and completes our objective.