• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.73-75
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• 2019

폐배터리를 조합하여 배터리 팩을 구성 시, 사용환경이 상이한 폐배터리 간의 전압/SOC의 편차가 존재하여 장기간 사용시 과충전/과방전과 같은 안전상을 문제가 발생할 가능성이 크다. 따라서 본 논문에서는 확장 칼만 필터를 기반 센서 융합 방법을 사용하여 폐배터리 팩의 셀 간 SOC 불균형을 추정하는 알고리즘을 제안한다. 검증은 셀간 전압 불균형이 있는 노화된 배터리 팩에 임의의 전류 프로파일을 인가하여 제안된 알고리즘을 검증한다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.289-290
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• 2014

3kWh 급 가정용 Energy Storage System (ESS)는 배터리 팩의 수명 관리상 배터리팩의 전압을 48V의 공칭전압으로 설계하는 것이 일반적이다. 상용 변압기를 사용하여 48V의 낮은 직류 링크 전압을 갖는 ESS를 220V 교류 계통과 연계하기 위하여는 30V 정도의 낮은 인버터 출력단 교류전압을 220V로 승압하여야 한다. 이 경우 ESS의 교류 측 전압 및 전류 파형을 정형적으로 만들어주기 위한 LC 필터 요소로서 저전압/대전류 용 필터 인덕터를 제작하는 것이 쉽지 않다. 다시 말해, 성능이 보장된다면 교류 측 LC 필터를 상용 변압기의 고전압 측에 설치하는 것이 바람직하다. 본 논문에서는 상용 변압기를 사용하는 가정용 ESS의 교류 측 필터의 설치 위치에 따른 설계 및 제작 시 고려 사항과 특성에 대하여 연구하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.345-346
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• 2014

본 논문에서는 배터리팩의 안전한 충방전 관리를 위해 배터리팩의 전류 제한 지표인 state-of-power (SOP)를 구하는 알고리즘을 제안한다. 직렬 연결된 배터리 팩의 SOP를 구하기 위해서는 각 셀의 배터리 파라미터 추정 과정이 필수적이다. 이를 구현하기 위해 듀얼 확장 칼만 필터 (DEKF)를 사용하였으며 효율적인 운용을 위해 DEKF의 사용량을 줄이는 방안을 제시한다. 실험을 통해 배터리 파라미터 추정 결과를 확인하였다.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.249-251
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• 2018

본 논문에서는 모델 기반 적응제어 방식중 하나인 확장 칼만 필터(EKF: Extended Kalman Filter)를 사용하여 전기자전거용 배터리팩의 충전량(SOC: State of Charge)을 상온과 저온에서 추정하였다. 온도에 따라 배터리의 특성은 매우 가변적이며, 모델의 특성이 달라짐에 따라 적응제어를 위한 내부 파라미터 또한 상이하게 나타난다. 본 논문에서는 Matlab/Simulink를 이용하여 배터리와 확장 칼만 필터를 설계하고 시뮬레이션하였다. 온도에 따른 최적의 SOC 추정 성능을 얻기 위해, 오차 원인을 분석하고 이에 따른 개선된 SOC 추정 결과를 나타냈다.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.2
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• pp.147-159
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• 1997

One of the most critical problems associated with filter-pack data comparisons from various field networks is the use of different sampling flow rates. In this field study, the effects of various filter-pack(FP) sampling conditions were examined. Experiments were conducted to evaluate the effects of varying sampling flow rates (1.5 to 10 sLpm) on measured concentrations of dry acid deposition species. Collocated FP samples were also collected to determine sampling and analysis data reproducibility. Ambient air samples were collected simultaneously for the seven day durations at varous flow rate. The chemical species measured were sulfur dioxide ($SO_2$), particulate sulfate(P-$SO_{4}^{2+}$), nitric acid ($HNO_3$), and particulate nitrate (P-$NO_{3}^{-}$). The results indicated that the collocated samples can be measured reproducibly and that sampling bias for the species measured is not significant. It was concluded that variations in the flow rates (1.5 to 10 sLpm) did not significantly affect the concentration of the species of interest. Although the results were not significantly different between different flow rates, artifacts were more likely to occur at high flow conditions (>5 sLpm) (e.g., via volatilization of particulate nitrates) than at low flow conditions(<5 sLpm).

• ETRI Journal
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• v.7 no.2
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• pp.18-25
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• 1985

현재의 TDX-1 에서 사용되는 푸쉬버튼 수신기는 애널로그형으로 TDM방식의 디지틀 교환기인 TDX-1 에는 적합치 못하며 애널로그방식의 푸쉬버튼 수신기는 채널당 한 회로가 필요하게 되어 32채널 수용시 경제성 및 회로 팩 부피에서 불리한 입장이다. 따라서 본고에서는 디지틀화 추세에 따라 디지틀 필터 방식에 의한 디지틀 푸쉬버튼 수신기를 구성하여 채널을 다중화할 수 있으며, 이에 따라 애널로그 방식보다 경제성 및 집적도가 향상되며 안정도가 높은 디지틀 푸쉬버튼 수신기를 구성하는 방법을 제시하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1997.10a
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• pp.190-191
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• 1997

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.237-243
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• 2017

Ignorance of battery pack life could bring unexpected UAV crashes and so the SOH estimation became a next important factor to the SOC estimation. In contrast to the EV applications, the small UAV could not carry heavy and complex BMS and so it is required to apply a simple, light, cheap, but powerful BMS to prevent any accident. In this paper, we show two SOH estimation methods, using internal resistance and using $SOC_I$ and $SOC_V$ with CF. Results show that the SOH becomes about 92% after 30 number of discharging cycles.

• Membrane Journal
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• v.33 no.6
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• pp.398-408
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• 2023

This work developed a hood and filter for antibacterial protective clothing for medical powered air purifying respirators (PAPR) that can be used in medical settings and quarantine against infectious diseases such as Zika virus, Middle East respiratory syndrome (MERS), and coronavirus disease-19 (COVID-19). The hood material of the protective clothing was made of polypropylene spunlace nonwoven fabric (SFS) was used for withstand wind pressure and external physcial pressure. Forthermore, in order to reduce the user's risk of infection, phytoncide-based materials were used on the outer-surface of the hood to achieve a 99.9% antibacterial effect, and the inner-surface were treated with hydro-philic materials to improve absorbency by 25%. In addition to evaluating the artificial blood penetration resistance, dry mi-croorganism penetration resistance, wet bacteria penetration resistance, and bacteriophage penetration resistance required for medical protective clothing hoods, it received a passing evaluation of levels 2-6. Meanwhile, as a result of evaluating the performance of the antibacterial treated spunlace high efficiency particulate air (HEPA) filter, excellent antibacterial properties, dust removal rate, and differential pressure effect were confirmed. All performance evaluations were conducted by an accredited certification body in accordance with the medical PAPR certification standards.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.1
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• pp.19-29
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• 2001

Atmospheric concentrations of acidic pollutant were measured by the 4 stage filter pak method at Chunchon and by the 3 stage filter pack method at Seoul and Anmyon-do from January to December 1998. The sample was collected for 24 hours on every Wednesday. Concentrations of particulate matters were highest at Anmyon-do. The particulate concentration was much higher during the warm season than other seasons. While the particulate concentration was higher during the warm season, the concentration of gaseous matter was higher in winter. Dry deposition flux was calculated by using reported deposition velocities and concentration of pollutants measured in this study. The dry deposition velocities used in this study for SO$_2$, SO$_{4}^{2}$, HNO$_3$,NO$_{3}^{-}$ and NH$_3$ were 0.29, 0.15, 2.08( 2.13 only for Anmyon-do), 0.20 and 1.00cm/sec, respectively. At Chunchon, annual sulfur flux originated from dry deposition was 384 kg/$textrm{km}^2$, and the flux from wet deposition was 782kg/$textrm{km}^2$. Dry deposition of sulfur was 33% of total sulfur deposition. The annual nitrogen flux originated from dry deposition was 1,892kg/$textrm{km}^2$. And the flux from wet deposition was 1,066kg/$textrm{km}^2$. Dry deposition of nitrogen was 64% of total nitrogen deposition. Dry deposition as well as wet deposition have to be considerd in the study on acidification of environment such as soil or watershed.