• 조명전기설비학회논문지
• /
• 제20권10호
• /
• pp.74-81
• /
• 2006

본 논문은 회전자 위치와 속도 정보를 가진 고정자 자속을 추정할 수 있는 프로그래머블 저역통과 필터를 이용한 비돌극 영구자석형 동기전동기의 센서리스 벡터제어를 제안한다. PLPF를 사용한 PMSM의 센서리스 벡터제어는 LPF와 순수적분기가 갖는 DC 드리프트 문제를 해결할 수 있다. 또한 PLPF는 정확한 회전자 위치와 속도 추정을 위해 위상과 이득 보상기를 갖는다. 그러므로, 드리프트와 옵셋 문제는 PLPF로써 해결되기 때문에 위치 및 속도의 정보는 정확히 추정된다. 실험결과는 정격속도의 10[%]이상과 부하상태에서 좋은 성능을 보여준다.

• 전기학회논문지
• /
• 제63권1호
• /
• pp.35-41
• /
• 2014

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.

• 한국자동차공학회논문집
• /
• 제22권6호
• /
• pp.23-30
• /
• 2014

This paper proposes a dead time compensation method for an AC motor drive using phase current polarity information which is detected based on a digital programmable low-pass filter (PLPF). The polarity detection using the PLPF is an alternative solution of a conventional method which uses a general low-pass filter (LPF) and hysteresis bands in order to avoid jittering due to noises. The PLPF not only adjusts its cutoff frequency according to the synchronous frequency of AC motors but also eliminates a gain attenuation and phase delay which are main problems of the general LPF. Through the PLPF, a fundamental component signal without gain and phase distortions is extracted from the measured raw current signal with noise. By use of the fundamental component, the polarity of current is effectively detected by reducing the hysteresis band. Finally, the proposed method compensates the dead time effects by adding or subtracting average voltage value to voltage references of the controller according to the detected current polarity information. The proposed compensation method is experimentally verified by compared with the conventional method.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2012년도 전력전자학술대회 논문집
• /
• pp.411-412
• /
• 2012

본 논문은 유도 전동기 센서리스 제어를 위해 자속 추정기로 사용되는 Programmable low-pass filter (PLPF)의 문제점 분석과 그 해결방안에 관한 연구이다. 기존의 PLPF는 추정된 동기 각속도를 극점으로 사용하고 실제 동기 각속도가 추정 값과 동일하다는 가정하에 순수 적분기와의 위상과 크기 오차를 보상한다. 하지만 추정 동기 각속도가 실제 값과 같지 않다면 이때 얻어진 크기와 위상 보상은 적절하지 않게 되고, 결과적으로 PLPF는 순수적분 기능을 제대로 수행할 수 없게 된다. 본 논문은 PLPF의 문제점을 극복하고자 동기 각속도 오차가 고정자 자속의 위상 지연 오차와 비례함을 분석하고, 이를 통하여 동기 각속도 오차를 보상하는 방법을 제안하였다. 제안한 방법의 타당성은 실험을 통하여 증명되었다.

• 전력전자학회논문지
• /
• 제18권3호
• /
• pp.232-239
• /
• 2013

This paper proposes an improved stator flux estimator through ensuring conventional PLPF to act as a pure integrator for sensorless control of induction motors. Conventional PLPF uses the estimated synchronous speed as a cut-off frequency and has the gain and phase compensators. The gain and phase compensators are determined on the assumption that the estimated synchronous angular speed is coincident with the real speed. Therefore, if the synchronous angular speed is not same as the real speed, the gain and phase compensation will not be appropriate. To overcome the problem of conventional PLPF, this paper analyzes the relationship between the synchronous speed error and the phase lag error of the stator flux. Based on the analysis, this paper proposes the synchronous speed error compensation scheme. To achieve a start-up without speed sensor, the current model is used as the stator flux estimator at the standstill. When the motor starts up, the current model should be switched into the voltage model. So a stable transition between the voltage model and the current model is required. This paper proposes the simple transition method which determines the initial values of the voltage model and the current model at the transition moment. The validity of the proposed schemes is proved through the simulation results and the experimental results.