• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.147-149
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• 2004

This paper presents a new velocity estimation strategy of a non-salient permanent magnet synchronous motor(PMSM) drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system which has the information of rotor position error. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error to zero. For zero and low speed operation, the PI gains of rotor position tracking controller have a variable structure. The PI tuning formulas are derived by analyzing this control system using the frequency domain specifications such as phase margin and bandwidth assignment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.211-213
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• 2007

The electrical parameters are used to calculate gains in the current regulator as well as to determine the reference currents of speed controller in various control strategies of Synchronous Reluctance Motors (SynRMs). Many methods of measuring or estimating the electrical parameters of SynRM have been proposed by other authors. But almost papers only measure or estimate in the limited conditions without fully considering the effects of inverter, connecting wire and magnetic saturation. The parameter results are usually different from the real system parameters. The drive performance, therefore, can not be good if using inaccurate parameters. In this paper, several methods used to measure the electrical parameters are introduced. The first method is LCR meter. And then, a method determining inductances by measuring AC current and voltage from AC power supply is presented. A new method with high reliability is proposed to measure the electrical parameters of SynRM. The experiment results verify the effectiveness of the new proposed method.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.991-997
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• 2008

A new RMRAC scheme far the PMSM current regulation is proposed in a synchronous frame, which is completely free from the parameter's uncertainty. A current regulator of PMSM is the inner most loop of electromechanical driving systems and plays a foundation role in the control hierarchy. When the PMSM runs in high speed, the cross-coupling terms must be compensated precisely for large system BW. In the proposed RMRAC, the input signal is composed of a calculated voltage defined by MRAC law and an output of the disturbance compensator. The gains of feed forward and feedback controller are estimated by the proposed modified gradient method, where the system disturbances are assumed as filtered current regulation errors. After the compensation of the system disturbance from error information, the corresponding voltage is fed forward to control input to compensate for real disturbances. The proposed method robustly compensates the system disturbance and cross-coupling terms. It also shows a good realtime performance due to the simplicity of control structure. Through real experiments, the efficiency of the proposed method is verified.

• 전기학회논문지
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• 제57권5호
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• pp.845-851
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• 2008

A simple RMRAC (Robust Model Reference Adaptive Control) scheme for the PMSM (Permanent Magnent Synchronous Motor) is proposed in the synchronous frame. A current control of PMSM is the most inner loop of electro-mechanical driving systems and it requires a fast and simple control law to play a foundation role in the control hierarchy. In the proposed synchronous current model, the input signal is composed of a calculated voltage by proposed adaptive laws and real system disturbance. The gains of feed-forward and feedback controllers are estimated by the proposed modified Gradient method respectively, where the system disturbances are assumed as filtered current tracking errors. After the estimation of the system disturbances from the tracking errors, the corresponding voltage is fed forward to control input voltage to compensate for the disturbances. The proposed method is robust against high frequency disturbance and has a fast dynamic response. It also shows a good real-time performance due to it's simplicity of control structure. Through the simulations and real experiments, efficiency of the proposed method is verified.

• 제어로봇시스템학회논문지
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• 제22권6호
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• pp.417-423
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• 2016

Using a sliding mode controller and observer techniques, this paper presents a robust current controller for a DC motor in the presence of parametric uncertainties. One of the most important issues in the practical application of sliding mode schemes is the chattering phenomenon caused by switching actions. This paper presents a novel sliding mode controller that incorporates an integral control with a sliding mode disturbance observer to attenuate the chattering by reducing the controller/observer switching gains. The proposed sliding mode disturbance observer is designed to estimate a relatively slow varying signal in the equivalent lumped disturbance owing to system uncertainties. Combining the estimated uncertainty with the sliding mode control input, the proposed controller can achieve the control objective by using the relatively low gain of the controller. The proposed disturbance observer does not include the switching control input of the baseline sliding mode controller to reduce the observer switching gain. In the proposed approach, the integral sliding mode control is used to improve the steady state control performance. Comparative computer simulations are carried out to demonstrate the performance of the proposed method. Through the simulation results, the proposed controller realizes the robust performance with reduced current ripples.

• 조명전기설비학회논문지
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• 제24권8호
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• pp.70-77
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• 2010

본 논문에서는 차세대 고속철도에 적용하기 위한 IPMSM 견인시스템의 전류 및 속도제어기를 설계한다. 차세대 고속철도는 동력분산식 시스템으로 개발되며 고효율화를 위해 IPMSM 적용 견인전동기를 사용하였고 전동기 제어를 위해 벡터제어 기법을 사용한다. 이 때 벡터제어 루프내 제어기 이득 값은 IPMSM의 과도특성과 속도제어 능력에 영향을 미치기 때문에 알맞은 이득 설계가 요구된다. 본 논문에서는 IPMSM 적용 차세대 고속철도용 견인전동기의 제어기를 설계하여 Matlab/Simulink 기반 모의시험 프로그램을 개발하고 이를 이용한 시험 결과를 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.67-69
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• 2007

PMSM (Permanent Magnet Synchronous Motor) current control is a most inner loop of electromechanical driving systems and it plays a foundation role in the hierarchy's control loop of several mechanical machine systems. In this paper, a simple RMRAC control scheme for the PMSM is proposed in the synchronous frame. In the synchronous current model, the input signal is composed of as a calculated voltage by adaptive laws and system disturbances. The gains of feed-forward and feed-back controller are estimated by the proposed e-modification methods respectively, where the disturbances are assumed as filtered current tracking errors. After the estimation of the disturbances from the tracking errors, the corresponding voltage is fed forward to control input to compensate for the disturbances. The proposed method is robust to high frequency disturbances and has a fast dynamic response to time varying reference current trajectory. It also shows a good real-time performance duo to it's simplicity of control structure. Through the simulations considering several cases of external disturbances and experimental results, efficiency of the proposed method is verified

• Journal of Power Electronics
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• 제15권4호
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• pp.1006-1017
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• 2015

This paper presents a finite control set model predictive control (FCS-MPC) strategy for the AC/DC matrix converter used in grid-connected battery energy storage system (BESS). First, to control the grid current properly, the DC current is also included in the cost function because of input and output direct coupling. The DC current reference is generated based on the dynamic relationship of the two currents, so the grid current gains improved transient state performance. Furthermore, the steady state error is reduced by adding a closed-loop. Second, a Luenberger observer is adopted to detect the AC input voltage instead of sensors, so the cost is reduced and the reliability can be enhanced. Third, a switching state pre-selection method that only needs to evaluate half of the active switching states is presented, with the advantages of shorter calculation time, no high dv/dt at the DC terminal, and less switching loss. The robustness under grid voltage distortion and parameter sensibility are discussed as well. Simulation and experimental results confirm the good performance of the proposed scheme for battery charging and discharging control.

• 보건교육건강증진학회지
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• 제18권2호
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• pp.1-26
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• 2001

This research is aimed to define how the depression, performing ability of IADL and muscular-skeletal pain of the Aged, according to their residential circumstance, sex and age, can affect the subjective health index and how all these are related and associated with. For the period of June 1 to July 31, 2000, in order to study and define how the depression, performing ability of IADL and muscular-skeletal pain are related to the subjective health index of the Aged, we have conducted an enquete through a direct interview with 693 persons over age sixty-five (65) in Daejon and in other adjacent areas, divided into three different residential types “The Aged living at home”, “The Aged living at welfare facilities” and “The Aged living alone”. We have studied all the data and information obtained through this enquete and have analyzed χ²-test, t-test, ANOVA, analysis of simple correlation, analysis of factor. by SPSS10.0/PC+. The results were as follows: Generally, the four (4) factors depression, IADL performing ability, muscular-skeletal pain and the subjective health index of the Aged, are a lot influenced by and related to their residential circumstance, their sex and their age. With regard to the depression of the Aged by their sex, it was analyzed that, on an average, the female-Aged gains 48.3 point which reflects comparatively the higher points and the female-Aged is more depressed. In analyzing depression of the Aged by their age, it appears that the Aged between eighty (80) to eight-four (84) years of age, gains 49.2 point which is the highest points and simultaneously we could realize that depression follows age, - the more the age gets, the more the depression is increased. In analyzing depression of the Aged by their residential type, it shows that “the Aged living alone” gains 50.9 point and is most depressed. With regard to the IADL performance of the Aged by their sex, it was analyzed that, on an average, the female-Aged gains 23.8 point, which shows the performance of the female-Aged is less independent. In addition, it was also found that the IADL performing ability is becoming less and less independent following their age increasing. In analyzing IADL performance by their residential type, it appears that “the Aged living at welfare facilities” gains the lowest 21.5 point and is least independent. We conclude that some assistances from others are required for the Aged living at welfare facilities in their performing IADL. With regard to the muscular-skeletal pain of the Aged by their sex, it was analyzed that, on an average, the female-Aged gains 3.0 point and the female-Aged suffers from this pain more severely. In analyzing this pain by their residential type, it was found that, on an average, the 3.0 point goes for “the Aged living alone”, which explains the Aged living alone is having the most serious pain. With regard to the subjective heath index of the all Aged participated in this research, the analysis indicates 8.8 point and this is considered as a general standard (7-10 point). In analyzing this index by their sex, the female-Aged gains 8.6 point only and it explains a lot of female-Aged consider they are not really healthy. In analyzing this index by their residential type, “the Aged living at welfare facilities” and “the Aged living alone” gain the comparatively lower point, -respectively 8.4 point for the Aged living at welfare facilities and 8.8 point for the Aged living alone. The Aged of these two residential types express they are obviously in a bad condition of health, which makes us think a lot. With regard to the factors affecting the subjective health index of the Aged, it was analyzed that this index can significantly be influenced by their depression, their pain, their age and by how much they are satisfied with their current living conditions, and also analyzed that the correlative relation certainly exists between the depression and pain, and the subjective health index, - that is, the more the depression and pain are serious, the lower the subjective health index indicates. As for the IADL, it appears that the IADL's relation with this index is not that significant and even not important.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.473-479
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• 2016

본 논문은 가격이 저렴하고 친환경적이면서도 고성능, 고내구성, 구조적 단순함의 장점을 갖고 있어 최근에 폭넓은 관심을 받고 있는 스위치드 릴럭턴스 모터(SRM: Switched Reluctance Motor)의 보다 정확하고 안정적인 전류제어 방법에 대해 설명한다. 대부분의 전동기의 전류제어 방법에는 알고리즘과 제어 이득의 선정이 다른 제어기에 비해 상대적으로 간편한 PI 제어기를 이용한 방법이 주로 사용되어 왔다. 그러나 일반적인 PI 제어기는 SRM과 같이 고정자 권선의 전류 및 회전자의 위치마다 비선형적으로 파라미터가 급변하는 시스템의 경우 변하는 동작 지점마다 제어 이득을 조정해 주어야 하는 어려움이 발생한다. 본 논문에서는 비선형적으로 특성이 변하는 SRM 드라이브 시스템에 제어 성능이 우수한 자기동조 퍼지 제어기를 이용한 제어기법을 적용하여 비선형적인 파라미터의 변화에도 보다 안정적인 전류제어가 가능한 것을 보였다. 또한 Matlab/Simulink 시뮬레이션을 이용하여, SRM 드라이브의 전류제어에 PI 전류 제어기(PICC: PI Current Controller)와 자기동조 퍼지 전류 제어기(STFCC: Self-tuning Fuzzy Current Controller)를 각각 적용한 후 그 결과를 비교하였으며 제안한 자기동조 퍼지 제어기의 제어성능이 우수함을 확인하였다.