| Title |
A Design of Programmable Low Pass Filter to Reduce the ZCP Estimation Error at High Speed BLDC Sensorless Drive |
| Authors |
서은정(Seo, Eunjeong) ; 이강석(Lee, Kangseok) ; 이우택(Lee, Wootaik) |
| DOI |
https://doi.org/10.5370/KIEE.2014.63.1.035 |
| Keywords |
Brushless DC motor ; Sensorless ; Zero crossing point ; Programmable low pass filter ; Measurement nois of terminal voltage ; Estimation error |
| Abstract |
This paper presents a design method of programmable low pass filter(PLPF) which reduce an estimation error of a zero crossing point(ZCP) for a high speed brushless DC(BLDC) motor drive. BLDC motor sensorless drive is possible by estimation of ZCP. The ZCP estimated by detecting a change of back-EMF polarity has the estimation error because noises exist on the measured back-EMF. Therefore a calculated commutation timing using the ZCP is inaccurate. And the inexact commutation timing leads to ripples of 3-phase current and degradation of drive performance. This paper proposes the design method of the PLPF to overcome these problems. First, a speed calculated a inaccurate period of the ZCP is analyzed in the frequency domain. Then, the PLPF that has varying cut-off frequency according to change of the speed is designed on the frequency analysis result. The proposed method is verified by the experiment. |