The sensor-less speed control driver with current feedback for three-phase brushless DC fan motor

The position sensor-less brushless DC (BLDC) motor driver was proposed in this work. The three-phase BLDC fan motors are utilized for cooling the computer products. Generally, the Hall sensor is used to extract the rotor position information. However, the sensor component is very sensitive to heat and noise signals. Therefore, the sensor-less control technique was developed. The proposed sensor-less speed control scheme was compare with the open-loop external PWM and closed-loop without external PWM control. Furthermore, the current feedback was employed to improve the system performance. By experimental results, the power consumption plots verified the proposed sensor-less control method can achieve high performance and high stability.