파라미터 보정을 가지는 풍력 동기발전기의 센서리스 최대전력 제어

채창호,권영안 한국마린엔지니어링학회 2017 한국마린엔지니어링학회지 Vol.41 No.9

The power control of a permanent magnet synchronous generator for the wind power generation is typically implemented through measuring the rotor speed or position. However, speed and position sensors require additional mounting space, reduce their reliability in harsh environments, and increase the cost of a generator. Various control algorithms for the elimination of speed and position sensors have been proposed. This paper investigates a sensorless control that eliminates the position and speed sensors in the maximum power control of a permanent magnet synchronous generator for the wind power generation system. Most sensorless control algorithms are based on the back-EMF and speed estimations obtained from voltage equations. Therefore, the sensorless control performance is largely affected by the parameter error of a generator. A novel sensorless control with the parameter compensation is proposed for the maximum power control in this paper. The proposed parameter compensation is obtained from the d-axis current error between the real and estimated currents. The proposed algorithm is verified through simulations and experiments. 풍력발전용 영구자석 동기발전기의 전력제어를 위해서는 회전자의 속도 및 위치 정보가 반드시 요구된다. 그러나위치 및 속도 센서들은 경제적인 문제점, 추가적인 센서의 부착 공간, 취약한 환경에서 신뢰도 감소 등의 단점을 가진다. 따라서 이러한 문제점들을 개선하기 위하여 회전자의 위치 검출기나 속도 센서가 없는 센서리스 제어 방식이 많이 연구되고 있다. 본 논문은 풍력발전용 동기발전기의 최대전력 제어에서 위치 및 속도센서를 제거하는 센서리스 제어에 관한연구이다. 대부분의 센서리스 제어 방식은 전압방정식으로부터 역기전력 정보와 속도 정보를 구하게 된다. 따라서 파라미터 오차는 센서리스 제어 성능에 큰 영향을 미치게 된다. 본 논문에서는 영구자석 동기발전기의 센서리스 제어 성능을 개선하기 위해 역기전력 상수의 오차를 d축 전류의 측정치와 추정치를 이용하여 보상하는 방식을 제안하고 시뮬레이션과 실험을 통해 본 논문에서 제안한 방식을 검증한다.

일개 제조업 남성근로자에서 신체활동과 우울증상과의 관련성

채창호,박철용,손준석,Chae, Chang Ho,Park, Chulyong,Son, Jun Seok 한국산업보건학회 2017 한국산업보건학회지 Vol.27 No.3

Objectives: This study was conducted to assess the association between level of physical activity and depressive symptoms among Korean male workers. Methods: A self-administered questionnaire was distributed and anthropometric measurements were conducted with 1,379 male workers during a general health check. From this data, we identified the general characteristics, levels of physical activity(IPAQ), and depressive symptoms(CES-D) of the study population. We conducted univariate logistic regression to verify the variables that affect depressive symptoms and multivariate logistic regression to calculate odds ratios. Results: Among the 1,379 male workers, 43.4% were in the insufficiently active group(IPAQ category 1) and 22.8% were in the depressive symptom group($CES-D{\geq}16$). The odds ratio(OR) for depressive symptoms was statistically higher in the insufficiently active group, workers aged over 30, the shift work group, and the unmarried group. Adjusted for those variables, the ORs for depressive symptoms were found to be 1.45(95% CI=1.25-2.11), 1.15(OR=1.15, 95% CI=1.08-1.99) and 1.75(95% CI=1.48-2.02), for the insufficiently active group, workers aged over 30, and the shift work group, respectively. Conclusions: We found physical inactivity, age, marital status, and shift work to be associated with depressive symptoms among male workers. This study supports the suggestion that physical activity can be helpful to reduce depressive symptoms among workers.

수검자의 편리한 건강검진 및 효율적 관리방법을 통한 재수진율 향상

채창호,김영욱,손준석,김자현,민경범,김찬우,신영후,박승현,정운,김은정,구본석 한국의료QA학회 2009 가을학술대회 Vol.2009 No.2

일부 출판업 VDT 작업자들의 근골격계질환 자각 증상 호소율과 관련요인에 관한 연구

채창호,김영욱,이철호,김정일,김준연,이세훈 가톨릭대학산업의학센타 산업의학연구소 2003 韓國의 産業醫學 Vol.42 No.2

Objectives: This study was conducted to investigate the relationship between the self-reported musculoskeletal symptom prevalence and related factors among some VDT workers in publishing industries. Methods: The 201 study subjects consist of 130 VDT workers comprised of 59 edition workers and 71 data entry workers, and 71 Non-VDT workers. The study subjects were surveyed with structured self-reported questionnaire. Results: The prevalence of self-reported musculoskeletal symptom were 39.2% at neck, 36.2% at back and waist, 30.8% at shoulder, 25.4% at hand and wrist and 9.2% at arm on VDT workers. In logistic regression analysis. Type of VDT(data entry worker) work was related factor of musculoskeletal symptom prevalence at neck, shoulder, arm, back and waist, hand and wrist. VDT working time and working condition were related factors at back and waist. At neck, shoulder, hand and wrist, sex was one of the related factors. Conclusion: Our finding revealed that sex and type of VDT work were main related factors of musculoskeletal symptom prevalence in study subjects.

일개 전자제품 제조업 근로자에서 교대근무와 불안증상: 비타민 D와 수면의 질의 매개효과

채창호,박영숙 한국산업보건학회 2020 한국산업보건학회지 Vol.30 No.3

Objectives: The purpose of this study was to compare vitamin D levels, sleep quality, and anxiety symptoms between shift workers and daytime workers and analyze the mediating effect of vitamin D and sleep quality between shift work and anxiety symptoms. Methods: The subjects of the study were 6744 people who received a medical examination while working for an electronics manufacturing company in 2016. We evaluated their shift work, vitamin D levels, sleep quality, and anxiety symptoms with blood samples and questionnaires. Chi-square test, t-test and path statistical analysis were performed. Results: The shift workers had significantly higher symptoms of anxiety than the day workers, significantly lower levels of vitamin D in the blood, and significantly poorer quality of sleep. The results of the pathway analysis confirmed that blood vitamin D and sleep quality had a mediating effect between shift work and anxiety symptoms. Conclusions: Shift workers should be constantly paying attention to mental health effects such as anxiety symptoms. Shift workers should also be alerted of the risk of vitamin D deficiency, encouraged about sun exposure and vitamin D intake, and required to undergo training and counseling on sleep hygiene.

청력변화에 대한 연령과 소음노출의 영향에 관한 시계열적 연구

채창호,김영욱,이철호,윤동영,김정일,홍영습,정갑열,김준연 대한산업의학회 2003 대한직업환경의학회 학술대회 논문집 Vol.30 No.-

청력에 대한 연령과 소음 노출의 영향에 관한 5년간 청력역치 변화

채창호 ( Chang Ho Chae ),김자현 ( Ja Hyun Kim ),손준석 ( Jun Seok Son ) 한국산업보건학회 2015 한국산업보건학회지 Vol.25 No.4

Objectives: This study was carried out to evaluate the effect of noise exposure and aging on changes in hearing threshold level and the relationship between age and noise. Materials: The author selected 274 male shipyard and assembly line workers as the noise exposed group and 582 males not exposed to noise as the general population group. Data were collected from five years of consecutive annual audiometric tests performed from 2008 to 2012. Results: In the general population and noise exposed groups, there was a reverse phenomenon that hearing threshold level for 2009 was lower than that of 2008, which seemed to be due to the learning effect, but from 2010 hearing threshold level increased. In the noise exposed group, the mean hearing threshold level in the left ear was significantly higher than that for right ear. In the general population group, the older was the age, the higher was the hearing threshold level, especially at 4000 Hz. In the general population and noise exposed groups, frequency, age group and noise exposure independently affected hearing threshold level, and there was no relationship between age and noise exposure. Over all frequencies, the change of hearing threshold level was larger in the noise exposed group than in the general population group. In the noise exposed group below thirty years old, the change at 4000 Hz was remarkable. Conclusions: Age and noise exposure seem to affect hearing threshold level independently and contribute to an additive effect on hearing threshold level.

인천지역 한 대학병원에서 진단된 기관지천식 중 직업관련성 천식

채창호,진영우,김은아,최승원,강성규,최용휴 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.2

Bronchial Asthma could be developed by occupational origin. 4-16% of bronchial asthmas are known to be related to occupational exposure. However, occupational asthma has not been reported from the periodic occupational health examination, but reported through case report from clinicians. The authors analysed hospital records to find out work-related bronchial asthma and their occupational characteristics at a university hospital in Inchon. All records which were confirmed as bronchial asthma in adult by an allegist from June, 1996 to May, 1998 were selected. Through record reviewing, any suspected work related asthma was selected and the inteview was done by phone or at the out-patient clinic. The possible cases were confirmed by additional tests including specific bronchial provocation test. Sixteen(3.9%) out of 411 bronchial asthma were confirmed as work-related asthma. Eight cases out of 16 worked at furniture industry, three worked at dye manufacturing and two worked at musical instrument manufacturing industry. Others worked at farm and machinary industry. The confirmed asthmogen were toluene diisocyante(8), reactive dye(3), and grain dust(1). None of the cases was detected as work-related asthma in the periodic health examination. Twelve out of sixteen occupational asthma patients discontinued their work. The results suggested that many patients with occupational asthma were not reported and the periodic health examination was not an effective system for detecting the workrelated asthma. Thus setting up the surveillance system involving allergist or pulmonologist would be important to detect and prevent occupational asthma.

인천지역 한 대학병원에서 진단된 수근관 증후군환자의 직업 관련성

최용휴,박정일,임종한,강성규,채창호 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.3

Objectives: The study was carried out to evaluate the work-relatedness and the occupational distribution in 147 carpal tunnel syndrome(CTS) cases diagnosed at a university hospital from May 1996 to May 1998. Methods: We obtained the information on disease appearance, occupational history including job content and other life style by medical records and telephone interviews. Results: Of the 147 patients with carpal tunnel syndrome, 51 patients(34.7%) were shown to be work-related. Work-related CTS were most frequent in elementary workers (21 case, 41.2%). The other cases were 15(29.4%) workers in service and shop and market sales, 9(17.6%) workers in craft and related trades, 4(7.8%) workers in skilled agriculture and fishery. Only two workers had claimed to the Industrial Accident Compensation Insurance, but no one has been admitted as an occupational CTS yet. Conclusions: It is suggested that arrangements of surveillance system for adequate control of occupational CTD is neccessity.

상태관측기를 사용한 풍력 발전기의 센서리스 최대전력 제어

채창호(Chang-Ho Chae),박준성(Jun-Sung Park),문철(Cheol Moon),이치우(Chee-Woo Lee),권영안(Young-Ahn Kwon) 대한전기학회 2014 대한전기학회 학술대회 논문집 Vol.2014 No.7