• 한국자동차공학회논문집
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• 제22권1호
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• pp.95-102
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• 2014

This paper presents zero crossing point(ZCP) estimation methods considering discretization error for a high speed brushless DC(BLDC) motor drive. The ZCP is estimated by detecting the change of back-EMF polarity for the BLDC sensorless drive, and the discretization error exist on the estimated ZCP. The discretization error of the ZCP is a cause of the delay of a commutation timing of current and increment of a current ripple factor. Besides a delay of a ZCP estimation brings on the limitation of a speed range for the BLDC sensorless drive. The compensation method based on the error analysis with probability theory for reducing the effects of the discretization error of the ZCP is proposed. Also a ZCP estimation method according to the Back-EMF patterns is proposed to widen the speed range for the BLDC sensorless drive. The proposed methods are verified by the experiment.

• 풍력에너지저널
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• 제2권2호
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• pp.54-60
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• 2011

A PMSG in variable speed wind turbine needs to know the position of rotor for vector control. Since the position sensor has the disadvantage in terms of cost, complexity of the system, a sensorless algorithm is needed. The sensorless strategy using the back EMF estimation is used for PMSG Wind Turbine. This algorithm is comparatively easy to implement than other strategies. This paper introduces the application of stable sensorless control for 2MW direct drive PMSG. In order to confirm the sensorless algorithm, the implementation is proceeded using 2MW direct drive PMSG from no-load condition to full-load condition. To drive 2MW PMSG artificially, 2MW PMSG connected PMSG through the mechanical coupling.

• 산업기술연구
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• 제34권
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• pp.15-20
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• 2014

Recently, PMSMs(Permanent Magnet Synchronous Motors) have become increasingly popular in various high-performance motor drive applications. However, the high-performance drive of PMSMs needs a position sensor such as a resolver, which increases not only the price of the system but also reduces the system reliability. This paper is on the implementation of sensorless control of a SPMSM, which drives a fan for cooling in appliances. In this paper, the rotor position for high-performance drive of a SPMSM is derived from back electromotive force (EMF) information proportional to the rotor speed. Also, the initial rotor position information for start-up is estimated from a saturation phenomenon of inductance. The validity of the proposed sensorless drives was confirmed by the experiment on the SPMSM drive systems for cooling fans of refrigerators and laptop computers.

• Journal of Advanced Marine Engineering and Technology
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• 제28권2호
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• pp.185-191
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• 2004

This study describes the scheme of vector drive system without speed sensor for AC servo motor using theory of a flux observer and based on the field oriented vector control. The new method of speed estimation is presented from operate with the position and magnitude of the secondary flux which obtain from the voltage reference and detected current. As the estimated speed is settled by the flux and the machine-specific parameters. this method don't need to adjust the gain of the parameter. Based on the derived theory for vector control. the scheme for sensorless vector drive of AC servo motor is designed and realized. And the experiment verifies it passable to realize the sensorless vector drive based on a field-oriented type.

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

• Journal of international Conference on Electrical Machines and Systems
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• 제2권1호
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• pp.91-96
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• 2013

Recently, it is increased to apply sensorless drive for BLDC (Brushless DC) motor to household electrical appliances, especially in the refrigerators and air conditioners, to reduce the cost and the acoustic noise by the operation and to make their functions more comfortable for human beings. In this paper, low-cost sensorless drive for BLDC motor is implemented by random PWM (Pulse Width Modulation). The experimental results show that the electromagnetic noise was reduced and the sound quality was improved by BLDC motor sensorless random PWM Control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1144-1145
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• 2007

This paper is investigated the sensorless drive for BLDC motor using microprocessor. Since the BLDC motor should be commutated according to a rotor position, the sensors are required to detect the position. But the sensors increase cost and volume, complicate the motor configuration, and do not operate properly in some operating environments such as high temperature conditions, so that the necessity of sensorless commutation algorithm is getting increased. This paper is proposed the method to drive BLDC motor without position-detecting sensor using Back EMF. Back EMF commutation method was implemented the sensorless drive system which could control the rotational speed and monitor the behavior of a motor.

• 전력전자학회논문지
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• 제12권2호
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• pp.157-164
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• 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.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.477-482
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• 2012

This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.

• 전력전자학회논문지
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• 제11권1호
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• pp.65-71
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• 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.