Title |
Performance Enhancement of Sensorless Drive for Brushless DC Motors using Digital Filter |
Authors |
여형기(Yeo, Hyeong-Gi) ; 김태형(Kim, Tae-Hyeong) ; 박정배(Park, Jeong-Bae) ; 이광운(Lee, Gwang-Un) ; 유지윤(Yu, Ji-Yun) |
Keywords |
brushless DC motor ; indirect sensing ; sensorless drive ; digital Butterworth filter ; discrete Fourier transform ; PWM |
Abstract |
This pper describes a digital sensorless drive of permanent magnet brushless DC motors. In order to detect in real time the rotor positions of which Emf becomes zero, terminal voltages are sampled during PWM duty cycle. This method generates detection error in indirect sensed position, which is the harmonic component of PWM frequency. In this paper, the drive adopted Butterworth low pass filter for rejection of the sensing error and for accurate estimation of commutation time. Analytical design process of the digital filter is proposed and the experimental results show that the performance of the proposed sensorless drive is superior to that of the sensorless drives without filterint. |