특수일사계를 이용한 맑은 날 일사량의 온도 보정

조일성(Zo Il-Sung),정명재(Jeong Myeong-Jae),이규태(Lee Kyu-Tae),지준범(Jee Joon-Bum),김부요(Kim Bu-Yo) 한국태양에너지학회 2015 한국태양에너지학회 논문집 Vol.35 No.1

Pyranometer have many uncertainty factors (sensitivity function, thermal offset, other spectral effect, geometric, environment, and equipment etc.) than pyrheliometer. The solution for most of the uncertainty factors have been researched, but the problem for thermal offset is being continued research so far. Under the clear sky, due to the thermal offset of pyranometer, the diffuse and global radiation have been negative value for the nighttime and lower value for the daytime, respectively. In order to understand the uncertainty of the thermal offset effect, solar radiation are observed and analyzed using Ji and Tsay method and date from modified pyranometer. As a result of performing temperature correction using the modified pyranometer, the slope (dome factor; k) and intercept (r0) from a linear regression method are 0.064 and 3.457 g·m<SUP>-2</SUP>·k<SUP>-1</SUP>, respectively. And the solar radiation is decreased significantly due to the effect of thermal offset during nighttime. The solar radiation from modified pyranometer increased approximately 8% higher than its observed by general pyranometer during daytime. By the way, these results and did not generalize because its result is for only single case in clear sky. Accordingly, it is to required for accurate results-obtained by the various cases (clear, cloudy and rainy) with longterm observations.

Thermopile Radiometer Calibration Using Reference Instrument

조덕기(Jo, Dok-Ki),윤창열(Yun, Chang-Yeol),김광득(Kim, Kwang-Deuk),강용혁(Kang, Young-Heak) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

The main purpose of the calibration procedure is to perform a one to one comparison of the reference pyranometer and the test pyranometer. In order to achieve this, both pyranometers need to be exposed to exactly the same irradiance, under the same circumstances. There are a number of error sources that could result in a wrong measurement. Most importantly Lamp instability, pyranometer offsets, thermal offsets of junctions, voltmeter offset, voltmeter instability, reference pyranometer instability, tilting of the pyranometers and differences in sensor height. Another sun-disc calibration procedure compares the computed vertical component of the direct irradiance as measured by a pyranometer with that measured by the pyranometer to be calibrated. Readings are taken with the levelled pyranometer on a clear day. Firstly the global irradiance and then the diffuse component are measured. Simultaneously measurement of direct irradiance is made with the pyrheliometer. The ways of performing the calibration and the subsequent calculation have been chosen such that the effect all these error sources has been eliminated as much as possible.

수평면 전일사량 측정데이터 보정에 관한 실험적 연구

송수원(Song Su-won) 한국태양에너지학회 2010 한국태양에너지학회 논문집 Vol.30 No.5

A Precision Spectral Pyranometer (PSP) is mainly used as a reference to calibrate other pyranometers due to its high accuracy and sensitivity in response to the spectrum wavelength range of 0.285? to 2.8?, while the sensitivity of photovoltaic-type Li-Cor pyranometer is limited within a certain spectral range from 0.4? to 1.1?. In this study, two Eppley PSPs(PSP₁ and PSP₂) were first compared to the calibrated Eppley PSPs from National Renewable Energy Laboratory (NREL), resulting in two linear correction factors based on the comparison between the logger output (V) from the test PSP and the solar radiation (W/m2) from the NREL PSP. The Li-Cor pyranometer used in this study was then corrected based on the comparison of measured solar radiation (W/㎡) from the corrected PSP₁ and the Li-Cor pyranometer. In addition, instrument scale corrections were also performed for the PSPs and the Li-Cor from the transmitter to the data logger. From the comparisons, a linear correction factor (1.0214) with R=0.9998 was developed for the scale correction between PSP₁ and PSP₂, while the Li-Cor pyranometer has a scale(1.0597) and offset (32.046) with R=0.9998 against PSP₁. As a result, it was identified that there were good agreements within ± 10W/㎡ between Eppley PSP₁ vs. PSP₂ solar radiation and within ± 20 W/㎡ between PSP₁ vs Li-Cor solar radiation after the empirical scale corrections developed in this study.

Analysis of the Thermal Dome Effect from Global Solar Radiation Observed with a Modified Pyranometer

조일성,이규태,지준범,김부요 한국광학회 2017 Current Optics and Photonics Vol.1 No.4

Solar radiation data measured by pyranometers is of fundamental use in various fields. In the field ofatmospheric optics, the measurement of solar energy must be precise, and the equipment needs to bemaintained frequently. However, there seem to be many errors with the existing type of pyranometer, whichis an element of the solar-energy observation apparatus. In particular, the error caused by the thermal domeeffect occurs because of the thermal offset generated from a temperature difference between outer domeand inner casing. To resolve the thermal dome effect, intensive observation was conducted using the methodand instrument designed by Ji and Tsay. The characteristics of the observed global solar radiation wereanalyzed by classifying the observation period into clear, cloudy, and rainy cases. For the clear-weathercase, the temperature difference between the pyranometer’s case and dome was highest, and the thermaldome effect was 0.88 MJ m-2 day-1. Meanwhile, the thermal dome effect in the cloudy case was 0.69MJ m-2 day-1, because the reduced global solar radiation thus reduced the temperature difference betweencase and dome. In addition, the rainy case had the smallest temperature difference of 0.21 MJ m-2 day-1. The quantification of this thermal dome effect with respect to the daily accumulated global solar radiationgives calculated errors in the cloudy, rainy, and clear cases of 6.53%, 6.38%, and 5.41% respectively.

표면도달일사량 검증 시 발생하는 시간 불일치 조정을 통한 정확한 일사량 검증: MTSAT-1R 자료 이용

염종민 ( Jong Min Yeom ),한경수 ( Kyung Soo Han ),이창석 ( Chang Suk Lee ),김도용 ( Do Yong Kim ) 大韓遠隔探査學會 2008 大韓遠隔探査學會誌 Vol.24 No.6

본 연구에서는, MTSAT-1R 위성 자료를 이용하여 표면도달일사량 (SSI: Solar Surface Insolation)을 산출한다. 표면도달일사량은 태양-지구에너지시스템, 기후변화, 그리고 농업 생산 예측 모델 활용과 같은 다양한 분야에 사용되는 주요 변수이다. 대부분의 표면도달일사량 산출모델은 지상 관측 일사계 자료를 이용하여 모델의 검·보정을 수행한다. 위성자료를 이용하여 산출된 표면도달일사량과 지상 관측 일사값을 서로 비교할 때, 기기 차에 의해 발생하는 시스템 오차가 존재한다. 지상 관측 일사계의 경우에는 2분마다 관측된 전천 일사량을 평균하여 시간일사 대푯값으로 제공하다. 반면 위성을 이용하여 산출된 표면 도달일사량의 경우에는, 특정시간에 대한 순간 관측 값을 이용하며, 단위 화소 크기에 대한 공간 해상도로 제공된다. 시스템 차에 의해 발생하는 시간적 불일치는 지상 관측 값과의 검·보정 시, 오차 값을 포함한다. 본 연구에서는, 시간 불일치 조정을 통해 보다 향상된 표면도달일사량 검증 기법을 제공하고자 한다. In this study, we estimate solar surface insolation (SSI) by using physical methods with MTSAT-1R data. SSI is regarded as crucial parameter when interpreting solar-earth energy system, climate change, and agricultural production predict application. Most of SSI estimation model mainly uses ground based-measurement such as pyranometer to tune the constructed model and to validate retrieved SSI data from optical channels. When compared estimated SSI with pyranometer measurements, there are some systemic differences between those instruments. The pyranometer data observed upward-looking hemispherical solid angle and distributed hourly measurements data which are averaged every 2 minute instantaneous observation. Whereas MTSAT-1R channels data are taken instantaneously images at fixed measurement time over scan area, and are pixel-based observation with a much smaller solid angle view. Those temporal discrepancies result from systemic differences can induce validation error. In this study, we adjust hour when estimate SSI to improve the retrieved accurate SSI.

Development of Sensor Node Prototype using Solar Module with Dual Purpose

( Joonyong Kim ),( Young-moo Jung ),( Ji-soo Kim ),( Joong-yong Rhee ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

A pyranometer, which measures solar radiation, is expansive for a farmer to use. The solar module used as a power source could be used to measure solar radiation. This research was to develop a sensor node with a solar module. Three research parts have been set up to effectively develop the node. The first part is to tune an artificial intelligence model that can calculate solar radiation using short circuit current of solar module and weather information. The second part is to design a sensor node considering the power consumption and capacity of power. The third part is to develop a gateway that can be used to receive and process the transmitted data wirelessly. The prototype had worked for a month with 98% transmission rate. Since the voltage of battery changed within 5.6~6.4V, it would be enough to operate continuously. It is possible to supply a cheaper sensor node for measuring solar radiation rather than a pyranometer.

강릉원주대학교 복사-위성연구소에서 실외 비교관측을 통한 전천일사계 교정

지준범,조일성,김부요,이규태,유명선,이용주,장정필 한국지구과학회 2019 한국지구과학회지 Vol.40 No.2

Although the technology for the observation of solar radiation is rapidly developing worldwide, in Korea the guidelines for comparing observations of solar radiation are only now under preparation. In this study, a procedure for intercomparison observations of solar radiation was established which accounts for meteorological and geographical conditions. The intercomparisons among observations by national reference pyranometers were carried out at the Asia Regional Radiation Center, Japan, in 2017. Recently, the result of the calibration of the reference pyranometer of the Korean Meteorological Administration (KMA) has been reported. Using the KMA pyranometer as a reference, comparisons between observations and calibrations were carried out for the standard (B to J) pyranometers of the KMA, and for the reference (A) and the standard pyranometers of the Gangneung-Wonju National University. The intercomparisons were carried out between October 24 and October 25, 2018. The sensitivity constants were adjusted according to the results of the data analysis performed on October 24. On October 25, a post-comparison observation was also performed, and the data of the participating pyranometers were verified. The sensitivity constants were calculated using only data corresponding to a solar radiation of 450Wm−2 or higher. The B and I pyranometers exhibited a small error (±5Wm−2), and the applied sensitivity constants were in the range 0.08-0.16 µV (Wm−2)−1. For the C pyranometer, the adjustment of the sensitivity constant was the largest, i.e., −0.16 µV ( W m−2)−1. As a result, the nine candidate pyranometers could be calibrated with an average error of 0.06Wm−2 (0.08%) with respect to the KMA reference, which falls within the allowed tolerance of ±1.00% (or ±4.50Wm−2). Keywords: Pyranometer, Calibration, Intercomparison, Sensitivity Constant, World Radiation Center 전세계적으로 일사계 비교관측 기술은 급격히 발전하고 있지만 국내의 경우 일사 비교관측 표준지침을 준비하고 있는 실정이다. 본 연구에서는 국내 기상 및 지리적 환경을 고려하여 전천일사계의 비교관측 절차를 정립하였다. 2017년 아시아 지역 복사센터에서는 국가표준 일사계들의 비교관측을 통해 일사계 보정이 이루어졌다. 이때 검교정된 기상청 기준기를 이용하여 기상청의 부기준기들과 강릉원주대의 전천일사계의 비교관측 및 검교정이 수행되었다. 비교관측 및 검교정은 2018년 10월 24일부터 10월 25일(2일)까지 수행되었으며 비교관측자료를 분석하여 오차분석 및 검교정을 수행하였다. 보정전 비교관측에 따르면, 전천일사계 부기준기들(B-J)은 기상청 전천일사계 기준기(A)를 기준으로 ±12.0Wm−2 이하의 편차가 나타났고 B와 I 전천일사계는 ±4.0Wm−2 미만의 작은 편차를 보였다. 태양 복사량이 450Wm−2 이상인 자료들을 이용하여 감도정수의 보정값을 계산하였다. B와 I 일사계(오차 ±0.5Wm−2 이하)를 제외한 일사계들(오차 ±5Wm−2 이상)은 0.08-0.16 µV (Wm−2)−1 감도정수 변경이 적용되었다. C 일사계는 감도정수의 변화가 가장 컸으며 감도정수는 −0.16 µV ( W m−2)−1으로 보정하였다. 비교관측에 참가한 9종의 기준기 및 부기준기들의 최종 관측오차는 0.06Wm−2 (0.08%) 이하였으며 허용범위인 ±1.00% (±4.50Wm−2)로 검교정되었다.

Realization of Solar Sensing Device

Hyeok Jae Woo,Sung Ho Kim,Kyoo Jae Shin 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.9

In this paper, the solar sensing device used to measure the solar radiation whether it is same in all directions or maximum in the particular direction to convert it into the more electricity. The solar servo control tracking device using a pyranometer is disclosed. The device includes: a solar panel; a tracker having a solar panel driving motor driving the solar panel; a tracker controller controlling the tracker; first pyranometers measuring a solar azimuth in EW and detecting solar radiation of 380 nm to 840 nm wavelengths; second pyranometers measuring a solar azimuth in NS and detecting solar radiation; and a third pyranometer measuring a solar azimuth in the CE and detecting solar radiation. The tracker controller includes: signal amplifiers amplifying detection signals in three azimuths by the pyranometers; signal processors filtering the amplified detection signals by limiting a voltage; and a main control microcomputer outputting a control signal to the solar panel driving motor to stop the solar panel when the solar radiations are same and the solar radiations in one direction are maximum.

Soiling Effect Analysis on Pyranometer

Youmi Kim(김유미),Changyeol Yun(윤창열),Yongheack Kang(강용혁),Hyungoo Kim(김현구),Sangnam Lee(이상남),Hayang Kim(김하양),Minjoo Kim(김민주) 한국신재생에너지학회 2017 한국신재생에너지학회 학술대회논문집 Vol.2017 No.9

수평면 일사계의 노후화 및 현장교정에 관한 연구

이병길(Byeonggil Lee),장윤호(Yunho Jang),윤창열(Chang-Yeol Yun),강용혁(Yong-Heack Kang),김현구(Hyun-Goo Kim),김보영(Boyoung Kim) 한국태양에너지학회 2019 한국태양에너지학회 학술대회논문집 Vol.2019 No.4