• Title, Summary, Keyword: Weather Conditions

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Photovoltaic Generation System Simulation using Real Field Weather Conditions

  • Park, Min-Won;Yu, In-Keun
    • Journal of IKEEE
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    • v.5 no.2
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    • pp.121-127
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    • 2001
  • Actual system apparatuses are necessary in order to verify the efficiency and stability of photovoltaic(PV) generation systems considering the size of solar panel, the sort of converter type, and the load conditions and so on. Moreover, it is hardly possible to compare a certain MPPT control scheme with others under the exactly same weather and load conditions as well. For the purpose of solving above mentioned difficulties in a laboratory basis, a transient simulation of PV generation system using real field weather conditions is indispensable. A straightforward simulation scheme with cost effective hardware structures under real weather conditions is proposed in this paper using EMTDC type of transient analysis simulators. Firstly, a solar cell has been modeled with VI characteristic equations, and then the real field data of weather conditions are interfaced to the EMTDC through Fortran program interface method. As a result, the stability and the efficiency analysis of PV generation systems according to various hardware structures and MPPT controls are easily possible under the exactly same weather conditions.

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PV System Output Analysis Based on Weather Conditions, Azimuth, and Tilt Angle (기상조건, 방위각 및 경사각에 따른 태양광발전시스템 출력 분석)

  • Lee, Sang Hyuk;Kwon, Oh Hyun;Lee, Kyung Soo
    • Current Photovoltaic Research
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    • v.5 no.1
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    • pp.38-42
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    • 2017
  • PV system output is determined according to the weather conditions, the azimuth and tilt angle. Weather conditions are changing every moment and it seems to vary according to the daily, monthly, and annual basis. The azimuth and tilt angle is decided along the site conditions for the PV system installation. This paper analyzed the PV system output through the changing the weather conditions, the azimuth, and tilt angle. We compared the TMY data and analysis of the two major weather institutes which are KMA and METEONORM. PV system output trend were analyzed by changing the azimuth and tilt angle. We used simulation tool, which is named PVsyst for the entire PV system analysis.

Time-Profit Trade-Off of Construction Projects Under Extreme Weather Conditions

  • Senouci, Ahmed;Mubarak, Saleh
    • Journal of Construction Engineering and Project Management
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    • v.4 no.4
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    • pp.33-40
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    • 2014
  • Maximizing the profitability and minimizing the duration of construction projects in extreme weather regions is a challenging objective that is essential for project success. An optimization model is presented herein for the time-profit trade-off analysis of construction projects under extreme weather conditions. The model generates optimal/near optimal schedules that maximize profit and minimize the duration of construction projects in extreme weather regions. The computations in the model are organized into: (1) a scheduling module that develops practical schedules for construction projects, (2) a profit module that computes project costs (direct, indirect, and total) and project profit, and (3) a multi-objective module that determines optimal/near optimal trade-offs between project duration and profit. One example is used to show the impact of extreme weather on construction time and profit. Another example is used to show the model's ability to generate optimal trade-offs between the time and profit of construction projects under extreme weather conditions.

The Association between Weather Conditions and the Number of No-Show Patients at an Academic Medical Center (기상변화와 일개 대학병원 외래환자 예약부도와의 관련성)

  • Park, Il-Soon;Jung, Sang-Jin;Shin, Hwan-Ho
    • The Korean Journal of Health Service Management
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    • v.11 no.4
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    • pp.41-51
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    • 2017
  • Objectives : This study investigates the association between weather conditions and the rate of no-shows at an academic medical center. Methods : Electronic data regarding medical appointments atover the course ofone academic year (2016.03~2017.02) were used for analysis. Characteristics of weather conditions and the daily number of no-shows were compared by Chi-square test. A logistic regression was run to determine if certain aspects of weather affected the rate of no-shows. Results : The results reveal an overall no-show rate of 6.8% that appears to vary in accordance with specific weather conditions. Lower average temperatures, in particular, corresponded with a higher rate of no-show patients. This may indicate that o-show rates in autumn and winter can be expected to exceed those during spring. Conclusions : This study investigates the association between no-show patients and weather conditions, and offers suggestions for augmenting this loss. One recommendation is to begin conducting investigations nationwide in order to provide more useful information.

Implementation of a Weather Hazard Warning System at a Catchment Scale (시스템 구성요소 통합 및 현업서비스 구축)

  • Shin, Yong Soon
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • pp.74-85
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    • 2014
  • This study is a part of "Early Warning Service for Weather Risk Management in Climate-smart Agriculture", describes the delivery techniques from 840 catchment scale weather warning information using 150 counties unit special weather report(alarm, warning) released from KMA(Korea Meteorological Administration) and chronic weather warning information based on daily weather data from 76 synoptic stations. Catchment weather hazard warning service express a sequential risk index map generated by countries report occurs and report grade(alarm, warning) convert to catchment scale using zonal summarizing method. Additional services were chronic weather warning service at crop growth and accumulated more than 4 weeks, based on an unsuitable weather conditions, representing a relative risk compared to its catchment climatological normal conditions (normal distribution ) in addition to special weather report. Service provided by a real-time catchment scale map overlaid with VWORLD open platform operated by Ministry of Land, Infrastructure and Transport. Also provide a foundation for weather risk information to inform individual farmers to farm located within the catchment zone warning occur.

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Analysis on the Effects by Weather Conditions of Infrared Thermography (기상조건이 적외선 열화상에 미치는 영향 분석)

  • Lim, Young-Bae;Choi, Myeong-Il;Kim, Gi-Hyun;Park, Chee-Hyun;Bae, Seok-Myung;Cho, Sung-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.56 no.3
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    • pp.142-147
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    • 2007
  • Infrared thermography is one of the most valuable and cost-effective diagnostic techniques for predictive maintenance on electrical systems. For the electric installations, the thermographies can identify major problems, which if left unattended could lead to breakdowns. The result thermal images depend upon operator skills, inspection technique, and load and weather conditions. When the thermographer is applied to remote monitoring, the conditions of the systems are not perfectly analyzed because operators are hard to know the weather's effects of the installed place. Therefore, this paper defines the effects by weather conditions which will influence the final results. The purpose of this paper is to define the weather effects that a thermographer needs to consider for successful condition analysis.

Analysis on Electrical Characteristics of PV Cells considering Ambient Temperature and Irradiance Level (주변온도와 일사량을 고려한 PV Cell의 전기적 특성 분석)

  • Park, Hyeonah;Kim, Hyosung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.6
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    • pp.481-485
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    • 2016
  • When analyzing economic feasibility for installing a PV generation plant at a certain location, the prediction of possible annual power production at the site using the target PV panels should be conducted on the basis of the local weather data provided by a local weather forecasting office. In addition, the prediction of PV generating power under certain weather conditions is useful for fault diagnosis and performance evaluation of PV generation plants during actual operation. This study analyzes PV cell characteristics according to a variety of weather conditions, including ambient temperature and irradiance level. From the analysis and simulation results, this work establishes a proper model that can predict the output characteristics of PV cells under changes in weather conditions.

Estimation of Doppler Spectrum Modes in a Weather Radar for Detection of Hazardous Weather Conditions

  • Lee, Jong-Gil
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.3A
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    • pp.205-210
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    • 2002
  • In a Doppler weather radar, high resolution windspeed profile measurements are needed to provide the reliable detection of hazardous weather conditions. For this purpose, the pulse pair method is generally considered to be the most efficient estimator, However, this estimator has some bias errors due to asymmetric spectra and may yield meaningless results in the case of a multimodal return spectrum. Although the poly-pulse pair method can reduce the bias errors of skewed weather spectra, the modes of spectrum may provide more reliable information than the statistical mean for the case of a multimodal or seriously skewed spectrum. Therefore, the idea of relatively simple mode estimator for a weather radar is developed in this paper, Performance simulations show promising results in the detection of hazardous weather conditions.

Analysis of the Correlation on the Weather Conditions and the Contamination Degree Using Mu lisle Regression Method (다중회귀를 이용한 기후와 오손도 간의 상관관계 분석)

  • 심규일;최남호;김종석;한상옥
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.199-202
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    • 2001
  • This paper presents the correlation on the contamination degree and weather conditions using the multiple regression of the statistic method. The cotamination is a significant factor in the insulation system. The major factor is natural contamination, and the most is the salt. The salt contamination is occured by the weather conditions. The weather contaminations are wind, precipitation, temperature, relative humidity, etc. The effects of those are different, and the correlation is showed numerically by using the multiple regression method of the statistic method. With this, the estimation of the equivalent salt deposit density(ESDD) becomes possible by the changes of the weather conditions.

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Simulating Crop Yield and Probable Damage From Abnormal Weather Conditions (이상기후에 따른 농작물의 수확량 및 재해발생 확률의 추정)

  • 임상준;박승우;강문성
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.39 no.6
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    • pp.31-40
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    • 1997
  • Potential impacts for unfavourable weather conditions and the assessment of the magnitudes of their adverse effects on crop yields were studied. EPIC model was investigated for its capability on crop yield predictions for rice and soybean. Weather generationmodel was used to generate long-term climatic data. The model was verified with ohserved climate data of Suwon city. Fifty years weather data including abnormal conditions were generated and used for crop yield simulation by EPIC model. Crop yield probability function was derived from simulated crop yield data, which followed normal distribution. Probable crop yield reductions due to abnormal weather conditions were also analyzed.

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