| Title |
Sensorless Precision Speed Control of PM BLDC Motor |
| Authors |
Yuen-Chung Kim ; Yong-Ho Yoon ; Hack-Seong Kim ; Byuong-Kuk Lee ; Chung-Yeun Won ; Jang-Sung Chun |
| Keywords |
PM BLDC Motor ; Sensorless Speed Control ; Third harmonic ; Johnson Counter ; PLL |
| Abstract |
This paper studies particularly applicable method for sensorless PM BLDC motor drive system. The waveform of the motor internal voltages(or back emf) contains a fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition. Also because of low resolution of estimated signal obtained by the proposed sensorless algorithm, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on estimated signals. Some experimental results are provided to demonstrate the validity of the proposed control method. |