• Journal of Power Electronics
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• 제17권3호
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• pp.704-715
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• 2017

For three-phase synchronization applications, the synchronous reference frame phase-locked loop (SRF-PLL) is probably the most widely used technique due to its ease of implementation and satisfactory phase tracking performance under ideal grid conditions. However, under unbalanced and distorted grid conditions, its performance tends to worsen. To deal with this problem, a variety of filtering stages have been proposed and used in SRF-PLLs for the rejection of disturbance components at the cost of degrading the dynamic performance. In this paper, to improve dynamic performance without compromising the filtering capability, an effective hybrid filtering stage is proposed and incorporated into the inner loop of a quasi-type-1 PLL (QT1-PLL). The proposed filtering stage is a combination of a moving average filter (MAF) and a modified delay signal cancellation (DSC) operator in cascade. The time delay caused by the proposed filtering stage is smaller than that in the conventional MAF-based and DSC-based PLLs. A small-signal model of the proposed PLL is derived. The stability is analyzed and parameters design guidelines are given. The effectiveness of the proposed PLL is confirmed through experimental results.

• 대한기계학회논문집A
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• 제34권12호
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• pp.1925-1930
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• 2010

겐트리형 리니어 모터의 주행 축은 동기화가 필수적이며 그렇지 못할 경우에는 위치의 어긋남이나 불안정한 동작으로 인해 동기오차가 발생하며 이는 고속 고정밀 선형운동에 악영향을 미친다. 또한 두 리니어모터의 축은 로터리 모터와 달리 동력 전달장치를 제거함으로 인해 모델의 불확실성이나 외란에 민감할 뿐만 아니라 마찰과 리플의 특성에 쉽게 영향을 받는다. 본 논문은 겐트리형 리니어 모터의 주행 축을 대상으로 위치제어에 악영향을 주는 대표적인 비선형 함수인 마찰력과 리플력을 추정하여 보상하며 두 축간의 동기오차를 줄이기 위해 동기제어 알고리즘을 설계하였다. 제안된 비선형 적응제어기는 모의실험을 통하여 성능을 검증하였다.

• 한국정밀공학회지
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• 제22권9호
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• pp.123-129
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• 2005

As the robot industry changes from industrial robot into personal robot used in home, the concept also changes from the existing fixed manipulator into Mobile Manipulator of free move in the aspect of appliance. For personal robot with such features, the role of mobile system is very important technology that rules the roost of robot functions. Especially, it is necessary to develop moving mechanism for free move in a narrow environment with obstacles such as home. This study introduces 3-axis structure in order to develop synchronous method that has turret capable of endless revolution for practical use as well as semi-omnidirectional function, and suggests applicable method to solve the problem of mechanical coupling.

• Journal of Power Electronics
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• 제1권1호
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• pp.1-8
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• 2001

The elimination of a pole sensor is desirable due to the low-cost requirement, the compactness, and the applied drives. This paper proposes the algorithm for the initial pole-position estimation of a surface permanent magnet linear synchronous motor (PM-LSM), which is carried out under the closed loop control without a pole sensor and is insensitive to the motor parameters. This algorithm is based on the principle that the initial pole position (IPP) is estimated by the trigonometric function of the two reference currents. The effectiveness of the proposed algorithm is confirmed by testing a surface PM-LSM with large disturbance, which result shows that IPP is well estimated within a satisfied moving-distance and a shorter estimation taken-time even if large disturbance such as cogging and friction is existed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.116-118
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• 2007

In this paper, the notch of teeth, the shape changing and skew of permanent magnet are used to reduce the detent force. And addition, overhang of permanent magnet is applied to increase thrust because thrust is decreased by skew. As the results, detent force is decrease greatly about 98(%). And, the ripple ratio of thrust is decreased from 11.34(%) to 0.25(%).

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.316-320
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• 2004

This paper presents an advanced method for an initial pole position estimation of a PMLSM (Permanent Magnet Linear Synchronous Motor) that has an incremental encoder for servo applications but does not have Hall sensors as a magnetic pole sensor. The proposed algorithm finds either of two zero force positions and then the correct d-axis by appropriately using the secant method as a numerical method. It only requires the tuned current controller and the relative position information and so it can be simply applicable to a rotary PMSM. The experimental results show the validity of the proposed method with respect to accurate pole position estimation under the minimal moving distance during estimation process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.228-230
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• 2005

In this paper, we address an active vibration control system, which suppresses the vibration engaged by magnetically levitated stage. The stage system consists of a levitating platen with four permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion via the vertical and horizontal forces. In the stage system, which represents the settling-time critical system, the motion of the platen vibrates mechanically. We designed an active vibration control system for suppressing vibration due to the stage moving. The command feedforward with inertial feedback algorithm is used for solving stage system's critical problems. The components of the active vibration control system are accelerometers for detecting stage tables's vibrations, a digital controller with high precise signal converters. and electromagnetic actuators.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.893-894
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• 2006

This paper presents a design and analysis solutions for the general class and control parameter estimation of slotted iron-cored Permanent Magnet Linear Synchronous Motor with Halbach magnetization stator and 3-phase winding mover. In our design and analysis, stator consisting of permanent magnets and slotted iron-cored coil mover are treated in a uniform way via magnetic vector potential. For one such motor structure, we give analytical formulas for its magnetic field, back electromotive force and trust force. Moreover, the detent force are calculated by the relative permeance function. In good agreement with the estimated values from the analyses, the experimental results and Finite Element Method (FEM) confirm the validity of the design and analysis framework.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.40-42
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• 2005

In this paper, thrust ripple is minimized using notch and slot-aperture width adjustment in a slotted PMLSM and then optimal design was achieved by using a neural network. This paper has used the moving model node technique to reduce the time and the effort for calculation according to changing design parameters. As the result, the detent force of optimal model is decreased from 9.44[N] to 0.97[N] greatly compare with it of basic model. The thrust is decreased 1.3[%] from 342.07[N] to 337.48[N] a little.

• 전력전자학회논문지
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• 제9권2호
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• pp.142-149
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• 2004

선형 영구자석형 동기 전동기는 기구학적인 변환 장치를 사용하는 기존의 방식과 비교하여 소음, 진동의 저감 및 가속도, 속도에 있어서 우수한 동특성을 가지고 있기 때문에 자동화 분야, 공작기계 및 반도체 장비를 중심으로 널리 사용되고 있다. 그러나 수직축(Z-axis)에 선형 영구자석형 동기 전동기가 적용될 경우에 제어를 위한 초기각 설정 및 상승, 하강 운전 특성을 향상시키기 위한 방법이 필요하다. 본 논문에서는 수직축 구조를 갖는 선형 영구자석형 동기 전동기의 초기각 설정 알고리즘 및 상승, 하강 운전 특성을 향상시키기 위해 실제 속도와 운전 방향을 변수로 하는 가변 이득 조절 알고리즘을 제안한다. 제안된 알고리즘들을 증명하기 위해서 4점의 절대위치 프로파일(profile)을 통해서 기존의 이득 시스템과 가변 이득 조절 시스템을 비교하여 제안된 알고리즘의 효용성을 검증하였다.