• 전력전자학회논문지
• /
• 제21권5호
• /
• pp.418-426
• /
• 2016

This paper analyzes the effect of resistance error to the performance of sensorless drive system of surface-mounted permanent magnet synchronous machine (SMPMSM) based on the back-EMF observer. The analysis shows that the bandwidth of the entire sensorless drive system decreased in the low-speed region when using smaller resistance value than the actual one in the back-EMF observer. Even if the back-EMF observer invokes estimation error, the entire sensorless drive system does not make any steady-state position error. These characteristics may have positive effects such as extension of the low speed limit that goes further down in the sensorless drive. The validity of the analysis is verified by the experimental setup comprising the MG set.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.220-223
• /
• 2005

In this paper, a novel sensorless brushless DC (BLDC) motor drive method using the fuzzy back-EMF observer is proposed to improve the performance of conventional sensorless drive methods. Most existing back-EMF sensing methods need additional circuit and have a low performance intransient state or low speed range. Therefore, this paper proposes the fuzzy back-EMF observer and an algorithm using this observer to estimate a speed and a position of the rotor. The robustness of the proposed algorithm is proved through the simulation compared with other sensorless drive methods.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.934-935
• /
• 2015

This paper presents the sensorless control method that employs the adaptive back-EMF(Electromotive Force) and current model observer of interior permanent magnet synchronous motor(IPMSM). The estimated back EMF considering a saliency is obtained by using the adaptive control method. The estimated EMF is inputted to the current model observer which is connected in series with adaptive back EMF estimator and is used to estimate the position and speed of the rotor. In order to improve the shortcomings of conventional method using the current error components multiplied in the compensation constant, the modified instantaneous reactive power compensator is applied. The validity of the control system presented is verified by the simulation.

• 전력전자학회논문지
• /
• 제18권4호
• /
• pp.367-375
• /
• 2013

The mechanical vibration of a PM synchronous motor at low speeds due to the back emf harmonics may be serious problems in some application such as MDPS(Motor driven power steering), electric vehicles. In this paper, torque ripple reduction for an interior PM synchronous motor including back emf harmonics is proposed. The dq flux linkage harmonics of the permanent magnet are estimated on real time by using the dq currents of the real system and the model of the MRAS observer. Based on the estimated flux linkage harmonics, the dq harmonic currents for reducing the torque ripples are compensated on the dq reference currents. The estimation of the flux linkage harmonics by the MRAS observer and the torque ripple reduction of the proposed algorithm was verified by the simulation and experiment.

• International Journal of Control, Automation, and Systems
• /
• 제6권4호
• /
• pp.477-487
• /
• 2008

This paper proposes a new position sensorless drive for brushless DC (BLDC) motors. Typical sensorless control methods such as the scheme with the back-EMF detection method show high performance only at a high speed range because the magnitude of the back-EMF is dependent upon the rotor speed. This paper presents a new solution that estimates the rotor position by using an unknown input observer over a full speed range. In the proposed method, a trapezoidal back-EMF is modelled as an unknown input and the proposed unknown input observer estimating a line-to-line back-EMF in real time makes it possible to detect the rotor position. In particular, this observer has high performance at a low speed range in that the information of a rotor position is calculated independently of the rotor speed without an additional circuit or complicated operation process. Simulations and experiments have been carried out for the verification of the proposed control scheme.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.215-219
• /
• 2005

In this paper, a novel motor control method is proposed to improve the performance of sensorless drive of BLDC motors. The unknown input (back-EMF) is modelled as the additional state of system in this paper. Taking into account the disturbance adopted by the back-EMF, the observer can be obtained by the augmented system equation. An algorithm to detect the back-EMF of the BLDC motor using the state observer is constructed. As a result, the novel sensorless drive of BLDC motors that can strictly estimate rotor position and speed is proposed.

• Journal of Power Electronics
• /
• 제12권4호
• /
• pp.604-614
• /
• 2012

This paper presents a comparative study of position sensorless control schemes based on back-electromotive force (back-EMF) estimation in permanent magnet synchronous motors (PMSM). The characteristics of the estimated back-EMF signals are analyzed using various mathematical models of a PMSM. The transfer functions of the estimators, based on the extended EMF model in the rotor reference frame, are derived to show their similarity. They are then used for the analysis of the effects of both the motor parameter variations and the voltage errors due to inverter nonlinearity on the accuracy of the back-EMF estimation. The differences between a phase-locked-loop (PLL) type estimator and a Luenberger observer type estimator, generally used for extracting rotor speed and position information from estimated back-EMF signals, are also examined. An experimental study with a 250-W interior-permanent-magnet machine has been performed to validate the analyses.

• 전력전자학회논문지
• /
• 제11권1호
• /
• pp.65-71
• /
• 2006

본 논문에서는 BLDC 전동기 센서리스 드라이브의 성능 향상을 위한 새로운 전동기 제어 기법을 제안한다. 최근 센서리스 제어방법의 주류를 이루고 있는 단자전압을 이용하는 방식들은 전동기를 동기 모드로 운전할 때 과도한 전압이 인가되면, 회전자 위치를 정확하게 검출할 수 없다. 특히 과도상태영역에서의 응답특성이 좋지 않다. 따라서 본 논문에서는 미지 입력인 역기전력을 추가적인 시스템의 상태로 모델링하고, 전체 시스템을 역기전력에 대한 미분방정식 형태 외란 모델을 도입한 확장 상태방정식으로 표현함으로서 얻어지는 상태관측기를 통하여 전동기의 속도 및 회전자 위치를 추정하는 새로운 알고리즘을 제안한다.

• 전력전자학회논문지
• /
• 제12권2호
• /
• pp.157-164
• /
• 2007

본 논문에서는 일반적인 브러시리스 전동기의 센서리스 구동 성능을 개전하기 위한 퍼지 역기전력 관측기를 이용한 새로운 센서리스 구동 방법이 제안되었다. 기존의 브러시리스 전동기의 센서리스 구동 방법은 저속영역과 과도상태에서의 성능저하와 추가적인 회로를 필요로 한다. 이러한 문제점을 보완하기 위해 사다리꼴 형태의 역기전력을 추정하기 위해 적합한 퍼지 논리에 의해 브러시리스 전동기의 역기전력을 정확하게 추정하였다. 퍼지 역기전력 관측기를 이용한 제안된 알고리듬은 정상 상태 뿐만 아니라 과도 상태에서도 연속적인 회전자 위치를 추정하고 외부 환경 변화에 강인한 제어를 얻을 수 있다. 제안된 알고리듬의 우수성은 다른 센서리스 구동방법과 비교한 시뮬레이션을 통하여 입증되었다.

• 반도체디스플레이기술학회지
• /
• 제14권3호
• /
• pp.45-50
• /
• 2015

This paper suggests the sensor-less speed control of PMSM (Permanent Magnet Synchronous Motor) without the position sensor of oil-free air compressor. It estimated d and q axis back electro motive force using Back-EMF (Electro motive Force) observer to control sensor-less speed of PMSM. Also it used the method that tracks the information of rotor position and speed using PLL (Phase Locked Loop) based on estimated d and q axis Back-EMF. The sensor-less speed control of PMSM for oil air compressor application is carried out with the introduced rotor position and speed tracking method. In this paper, the experimental characterization of the sensor-less drive is provided to verify the accuracy of the estimated position and the performance of sensor-less control is analyzed by results obtained from the experiment. Moreover, the potential of PMSM sensor-less drive in industrial application such as compressor drive is also examined.