직접토크제어에 의한 위치검출기 없는 리럭턴스 동기전동기의 고성능 제어시스템

김민회,김남훈,백원식 전력전자학회 2002 전력전자학회 논문지 Vol.7 No.1

This paper presents an implementation of digital high-performance position sensorless control system of Reluctance Synchronous Motor(RSM) drives with Direct Torque Control(DTC). The system consists of stator flux observer, speed and torque estimator, two digital hysteresis controllers, an optimal switching look-up table, Insulated Gate Bipolar Transistor(IGBT) voltage source inverter, and TMS320C31 DSP board. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control of which inputs are current and voltage sensed on motor terminal for wide speed range. In order to prove the suggested sensorless control algorithm for industrial field application, we have some simulation and actual experiment at low and high speed range. The developed high-performance speed control by fully digital system are shown a good response characteristic of control results and high performance features using 1.0[kW] RSM having 2.57 reluctance ratio of Ld/Lq. 본 논문은 직접토크제어에 의한 리럭턴스 동기 전동기의 위치센서 없는 고성능 제어시스템을 제안한다. 이 시스템은 고정자 자속관측기, 속도/토크 관측기, 두 개의 디지털 히스테리시스 제어기, 최적 스위칭 룩업 테이블, IGBT 전압형 인버터, 그리고 TMS320C31 DSP보드로 구성된다. 넓은 속도 범위에서의 안정된 응답특성을 얻기 위해서 전동기 단자에서 얻어진 전압과 전류를 사용하는 폐루프 자속관측기를 사용하였다. 개발된 고성능 속도제어 시스템의 동특성을 검증하기 위해서 1.0[kW] 리럭턴스 동기 전동기를 사용하여 시뮬레이션과 실험을 수행한 결과 저속영역과 고속영역 모두 우수한 동특성을 얻을 수 있었다.

스위치드 릴럭턴스 전동기의 구동원리 및 특징

김민회,백원식 전력전자학회 2002 전력전자학회지 Vol.7 No.5

[P2-16] 감마선 조사한 시판 도토리묵의 미생물학적·이화학적 특성

김민회,김미선,김미리 한국식품영양과학회 2007 한국식품영양과학회 학술대회발표집 Vol.2007 No.10

Transnational Memory of a Comfort Woman and Ethnic Identity in Nora Okja Keller’s Comfort Woman

김민회 미국소설학회 2013 미국소설 Vol.20 No.1

Transnational memory may result in the loss of essential meaning of the event itself in the mode of global conditions of cultural, historical and social differences. However, local memory in multiethnic American context can help American readers understand Asian Americans’ particular formation of ethnic or cultural identity based on their historical backdrops. From this perspective, this paper is to explore how Keller in Comfort Woman relocates the local memory of comfort woman at the transnational memory by replacing a comfort woman as a transnational mobile subject. It also discusses Keller’s politics of ethnic identity in this transnational mode by connecting such a local memory in Asia to an Asian American subject who is in dilemma of establishing ethnic identity. Keller’s Comfort Woman leads us to reconsider the problematic matters produced around the transnational memory, particularly in relation to a comfort woman. Moreover, she attempts to place the local memory of a comfort woman as important to understand what is defined to be Korean or Korean American in American society.

플렉서블 유기트랜지스터 센서 기술 동향

김민회,Kim, Min-Hoe 한국전기전자재료학회 2014 전기전자재료 Vol.27 No.11

直流電動機의 과도응답速度特性에 代한 硏究

金玟會 영남이공대학 1984 論文集 Vol.13 No.-

This paper describes the DC motor speed control system of transient state by a three phase full-wave converter. In this system, in order to improve response delay time for armature's inertia during transient condition (speed command variable, disturbance variable, and so forth on), the PID speed controller using an OP amplifier is designed. At the testing results, characteristic of transient response for DC motor speed can be improved.

A Five-Phase Induction Motor Speed Control System Excluding Effects of 3rd Current Harmonics Component

김민회,김남훈,백원식 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.3

In this paper an effective five-phase induction motor (IM) and its drive methods are proposed. Due to the additional degrees of freedom, the five-phase IM drive presents unique characteristics for enhancing the torque producing capability of the motor. Also the five-phase motor drives possess many other advantages when compared to traditional three-phase motor drives. Some of these advantages include, reducing the amplitude and increasing the frequency of the torque pulsation, reducing the amplitude of the current without increasing the voltage per phase and increasing the reliability. In order to maximize the torque per ampere,the proposed motor has concentrated winding, the produced back electromotive force (EMF) is almost trapezoidal, and the motor is supplied with the combined sinusoidal plus the third harmonic of the currents. For demonstrating the superior performance of the proposed five-phase IM, the motors are also analyzed on the synchronously rotating reference frame. To supply trapezoidal current waveform and to exclude the effect of the 3^rd harmonic current, a new control stratagem is proposed. The proposed control method is based on direct torque control (DTC) and rotor flux oriented control (RFOC) of the five-phase IM drives. It is able to reduce the acoustical noise, the torque, the flux, the current, and the speed pulsations during the steady state. The DTC transient merits are preserved, while a better quality steady-state performance is produced in the five phase motor drive for a wide speed range. Experimental results clearly demonstrated a more dynamic steady state performance with the proposed control system.

중국산과 국내산 헛개 나무 열매의 체내 알콜 분해능 및 간 해독 작용

김민회,정우택,이진하,박영식,신명기,김호상,김동훈,이현용 한국약용작물학회 2000 한국약용작물학회지 Vol.8 No.3

강원 양양산과 중국산 헛개 나무 열매와의 활성 차이를 비교하기 위해 쥐 와 사람을 대상으로 생체 내 알콜 분해 속도에 대한동력학적 분석을 실시한 결과 양양산이 중국산에 비해 1-2 % 로 극히 적게나마 빠른 알콜 분해 속도를 보였으며 분획물 에서도 이와 유사한 경향을 보였다. 하지만 이 정도의 차이가 두 품종 간 알콜 분해 속도에 차이가 있다고 주장하기에는 유의성이 적어 일반적으로 두 생산지의 차이에 따른 알콜 분해 속도의 차이는 극히 미미한 것으로 나타났다. 두 추출물 모두 알콜만 섭취했을 경우보다 1-2 시간 정도 빠르게 알콜을 분해했으며 유용 성분이 농축된 분획물의 경우 조 추출물보다 1-2 시간 정도 빨라 분획물을 섭취한 경우 알콜만 섭취한 경우보다 약 2 배 정도 빠른 혈중 알콜 분해 속도를 보였다. ADH 와 ALDH 의 활성 증진에 대한 영향을 비교한 결과 조 추출물의 경우 중국산이 양양산 보다 약간 높은 효과를 보였으나 분획물에서는 그리 큰 차이가 없거나 양양산이 다소 높은 경향을 보였다. 특이한 것은 ADH 의 경우는 두 종의 분획물 모두 조추출물 경우 보다 50-60% 이상 활성 증진 효과가 두드러지게 나타났으나 ALDH 의 경우는 두 분획물 모두 활성 증진이 조추출물에 비해 10% 정도의 낮은 활성 증진 정도만 나타났다. 전체적으로 알콜만 섭취한 경우에 비해 헛개나무 열매 추출물을 동시에 섭취한 경우 ADH와 ALDH 효소의 활성이 약 30-60% 이상 증가하는 것이 확인되었으며 두 효소위 활성 촉진 정도가 공히 28-29% 정도를 유지해 ADH 와 ALDH 의 활성이 생체 내에서 균형을 이루고 있음이 입증되었다. 또한 헛개나무 추출물들은 ADH 보다는 ALDH 효소의 활성에 보다 영향을 미치는 것으로 나타나 숙취 원인 물질인 acetaldehyde 의 제거 에 효과적일 것이라는 평가가 가능하다. 이와 함께 간의 해독 작용 촉진 정도를 비교한 결과 중국산 헛개나무 추출물이 양양산 보다 상대적으로 좋은 것으로 나타났다. 0.6 g/L 이상의 농도에서는 효소 활성이 어느 정도 저해되는 현상을 보여 헛개나무 추출물이 간해독작용에 관여하는 효소와 competitive inhibition 관계에 있을 수 있다는 추론을 할 수 있다 . 하지만 두 종 모두 조 추출물과 분획물의 경우 120-300% 이상의 GST 효소 활성 증진 효과를 보여 생산지에 관계없이 간 기능 활성이 중요한 역할을 하고 있음이 입증되었다. There was not noticeable differences in decreasing blood alcohol concentrations between Korea and China-produced Hovenia dulcis THUNB, showing only 1-2 % higher decreasing rate for Korea-produced seed extracts than those from China. It was also found that the blood alcohol decreasing ability was greatly enhanced by partitioning the crude extracts produced from both places. The both extracts (crude and partitioned) accelerated the reducing rate of blood alcohol concentrations down to 1-2 hours, compared to that of control (taking only ethanol). The crude extracts from imported seeds seemed to have slightly better effect on improving in vivo ADH and ALDH activities than domestic ones; however, not for partitioned extracts. It was interesting that the partitioned extracts from both countries enhanced ADH enzyme activity up to 60% than the crude, compared to the control, while ALDH activity was not much affected by the partitioned extracts. It was also confirmed that both ADH and ALDH activities were well balanced in controlling blood alcohol concentration maintaining 28-29% of enzyme activities in vivo. The extracts proved to have better effect on enhancing ALDH activity than ADH activity, which is one of possible explanation that Hovenia dulcis THUNB can effectively relieve the hangover by fast decreasing acetaldehyde concentration in the liver and blood. GST activity was also increased in the range of 120 to 300% by adding crude or partitioned extracts from both countries; however, there was no difference in enhancing GST activity between the extracts from two countries. The extracts showed competitive inhibition with GST activity, showing the reduction of enzyme activity at higher than 0. 6 (g/L) of the imported extracts.

三相誘導電動機 固定子捲線의 溫度上昇測定에 對한 硏究 (Ⅰ)

金玟會 영남이공대학 1980 論文集 Vol.9 No.-

In order to measure temperature rising in the stator winding of 3phase induction motor, it is necessary to normal loading (brake or generator). If it is utilize to new test method that two indentical mcchines are connentcd electrically (only) together and their losses are supplied externally, rate loading do not have to be mechanically coupled either to each other or to a third machine. In this principle, we can be temperature rising test in the stator winding of induction motors on the operating condition.

Reconsidering the Multicultural Movement toward the West Coast in Ishmael Reed’s Mumbo Jumbo

김민회 새한영어영문학회 2015 새한영어영문학 Vol.57 No.1

Believing that American multiculturalism should go beyond the geographical limits, Ishmael Reed in Mumbo Jumbo (1972) argues that the on-going American multicultural movement should be reconsidered not in a particular site like New York but in American society as whole. His ways of describing the self-inclusive and self-evolving movement of “Jew Grew” toward the West Coast and the undetermined meanings of “The Book of Thoth” are his symbolic attempts to describe American multiculturalism as the complexity and hybridity of different cultures, and the multiculturalism is not fettered by geographical convention. While considering the West Coast as an ideal place to produce American multiculturalism, Reed metaphorically uses the site in a way to extend the notion of American multiculturalism at the much more nationwide level. In doing so, Reed recreates his own notion of multiculturalism that can be separated from the heritage of the New York-centered multicultural movement in the 1920s.