건물외피에 적용되는 양면형 PV의 연구동향 및 기술제언 연구

정수연,한소원,이행우 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.6

Energy use in the building sector continues to grow and the increasing trend could be a serious problem. Photovoltaic (PV) modules, which have emerged as a solution to this problem, are now becoming one of the popular renewable energy sources that convert solar energy, an infinite resource, into electricity, and related research and application cases are increasing. In recent years, there has been a surge in research to induce the reduction in building energy by applying PV modules as building envelopes, and much attention has been directed towards bifacial PV modules, a structure that improves power generation efficiency. Since bifacial PV modules have two layers of PV cells and show higher power generation efficiency compared to the existing monofacial PV modules, the value of bifacial PV modules is considered to be high. Thus, this study aims to derive the research trend of bifacial PV modules and recommend future research directions by analyzing research on bifacial PV modules that are applied as building envelopes. To do this, this study analyzed the trends of bifacial PV modules based on the research on bifacial PV modules conducted in Korea, and the conclusions are as follows: 1) The efficiency of bifacial PV modules is higher than that of conventional monofacial PV modules, but the number of studies on their application as building envelopes is significantly insufficient. This is because monofacial PV modules have been popular and widely spread, thereby capturing a large share in the related markets, and this has led to the lack of awareness of bifacial PV modules. 2) Previous research on bifacial PV modules applied to building envelopes has focused on power generation efficiency. Thus, performance evaluation has been performed only with simple fixed types, so accurate verification of bifacial PV modules has not been conducted. Some studies have shown that bifacial PV modules of the movable type have high power generation efficiency, but even in these studies, there are research limitations in that the performance evaluation is carried out without considering the energy for moving. 3) We analyzed that the previous studies have limitations in that they do not closely examine the high heat generated by attaching PV cells to both sides of the bifacial PV module and the economic feasibility is also not assessed. In this regard, future studies on bifacial PV modules applied as building envelopes should avoid simply verifying the power generation efficiency. Moreover, it is necessary to advance the research on bifacial PV modules by conducting a study that considers multifaceted issues such as attaching and controlling bifacial PV modules to movable building envelopes. 건물부문 에너지사용량은 지속적으로 증가하는 추세로, 이에 대한 문제는 심각한 수준이다. 이를 해결하기 위한 해결책으로 등장한 PV모듈은 무한한 자원인 태양에너지를 전기에너지로 변환시키는 대표적인 신재생에너지로서 관련 연구와 적용사례가 증가하고 있다. 최근 연구에서 PV모듈을 건물외피로 적용함으로써 건물에너지 저감을 유도하는 연구들이 급증하고 있으며, 특히 발전효율을 높인 구조인 양면형 PV모듈에 대한 관심이 증가하고 있다. 양면형PV모듈은 PV cell을 2장 겹친 구조로 기존 단면형 PV모듈에 대비하여 높은 발전효율을 보이고 있기 때문에 그 가치는 높다고 판단된다. 이에 본 연구는 건물외피로 적용되는 양면형 PV모듈에 대한 연구를 분석함으로써 양면형PV 모듈의 연구 경향 도출과 향후 연구방향 제언을 목적으로 한다. 이를 위해 본 연구는 국내에서 수행된 양면형 PV모듈에 대한 연구를 근거하여 그 동향을 분석하였으며, 이에 대한 결론은 다음과 같다. 1) 기존 단면형 PV모듈에 대비하여 양면형 PV모듈의 효율은 높게 나타나고 있으나, 건물외피에 적용되어 수행된 연구의 수는 현저하게 부족한 실정이다. 이는 단면형 PV모듈의 보급 및 확산이 주를 이루어 관련시장에서 높은 점유율을 차지하고 있으며, 이에 따라 양면형 PV모듈에 대한 인식부족이 그 원인으로 사료된다. 2) 건물 외피 적용된 양면형 PV모듈 관련 선행연구는 발전효율에 초점이 맞춰져 있어, 단순 고정형태의 타입에 대한 성능평가가 이루어져 양면형 PV모듈에 대한 정확한 검증이 이루어 지지 않는 것으로 사료된다. 일부 수행된 가동타입의 양면형 PV모듈은 발전 효율이 높게 나타나고 있으나, 이러한 경우에도 가동을 위한 에너지를 배제한 채 성능평가가 이루어지고 있는 부분에서 연구적 한계를 보인다. 3) 선행연구는 양면형 PV모듈을 양면에 PV cell을 부착함에 따라 발생하는 발전 고열, 경제성 등에 대한 면밀한 검토가 이루어지고 있지 않다는 한계를 가지고 있는 것으로 분석된다. 이러한 측면에서 향후 건물외피로 적용되는 양면형 PV모듈에 대한 연구는 단순 발전 효율만을 검증하는 연구는 지양한다. 또한 가동형 건물외피에 양면형 PV모듈을 부착하여 제어하는 등 다각적인 문제를 고려한 연구를 수행함으로써 양면형 PV모듈연구를 고도화시켜야 할 것으로 사료된다.

태양광 발전시스템의 그림자 영향을 고려한 PV 모듈의 재구성

고재섭(Jae-Sub Ko),정동화(Dong-Hwa Chung) 한국조명·전기설비학회 2013 조명·전기설비학회논문지 Vol.27 No.2

This paper proposes the reconfiguration of PV module considering shadow influence of photovoltaic system. The PV system is consisted series-parallel connection of PV module. The voltage and current between PV modules become unbalance when shadow occurs to PV module. If shadow occurs to the series connection PV module, the output current is limited to current of shaded PV module. Also if shadow occurs to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, the PV module in this paper consist using the fixed module and variable module by shaded conditions. The reconfiguration of PV module can compensates the shadow influence by changing connection of a variable module when shadow is occurred to PV module. A validity of the reconfiguration of PV module proposed in this paper proves through comparing with performance of conventional PV module.

홀수스트링 PV모듈의 바이패스 다이오드 배치에 의한 전기적 특성

신우균(Shin Woo-Gyun),고석환(Go Seok-Hwan),주영철(Ju Young-Chul),송형준(Song Hyung-Jun),강기환(Kang Gi-Hwan) 한국태양에너지학회 2017 한국태양에너지학회 논문집 Vol.37 No.4

Most PV modules are fabricated by 6 cell-strings with solar cells connected in series. Moreover, bypass diodes are generally installed every 2 cell-strings to prevent PV modules from a damage induced by current mismatch or partial shading. But, in the case of special purpose PV module, like as BIPV (Building Integrated Photovoltaic), the number of cell-strings per module varies according to its size. Differ from a module employing even cell-strings, the configuration of bypass diode should be optimized in the PV module with odd strings because of oppositely facing electrodes. Hence, in this study, electrical characteristics of special purposed PV module with odd string was empirically and theoretically studied depending on arrangement of bypass diode. Here, we assumed that PV module has 3 strings and the number of bypass diodes in the system varies from 2 to 6. In case of 2 bypass diodes, shading on a center string increases short circuit current of the module, because of a parallel circuit induced by 2 bypass diodes connected to center string. Also, the loss is larger, as the shading area in the center string is enlarged. Thus, maximum power of the PV module with 2 bypass diode decreases by up to 59 (%) when shading area varies from 50 to 90 (%). On the other hand, In case of 3 and 6 bypass diodes, the maximum power reduction was within about 3 (W), even the shading area changes from 50 to 90 (%). As a result, It is an alternative to arrange the bypass diode by each string or one bypass diode in the PV module in order to completely bypass current in case of shading, when PV module with odd string are fabricated.

기계 하중에 따른 PV모듈 변형 분석

최주호(Choi, Ju-Ho),정태희(Jung, Tea-Hee),송희은(Song, Hee-Eun),김일수(Kim, Il-Soo),장효식(Chang, Hyo-Sik),강기환(Kang, Gi-Hwan) 한국태양에너지학회 2013 한국태양에너지학회 논문집 Vol.33 No.3

Recently, PV module that the most important part of the photovoltaic system is more widened to lower manufacturing costs for module. However, the broad PV module results to the serious mechanical damage coming from installation circumstances such as snow, wind etc of snow and finally lead to the dramatic degradation of the electrical behavior of PV module. In this paper, 3 kinds of PV modules that consist of the different thickness and area of front glass and the diverse cross sectional structures of the frame are prepared for this experiment. The drooped length and electrical outputs of the PV modules are measured by means of applying 600Pa mechanical load to the PV modules from 1200Pa to 5400Pa base on the mechanical load test procedure of K SC IEC 61215 standard. The simulation data are obtained by the simulation tool as ANSYS and those are validate by comparing with the those experimental results figure out relations between the deformation and the constituent part of PV module.

Configuration of PV Module Considering the Shadow Condition of PV System

Chang-Uk Lee,Jae-Sub Ko,Tae-Young Seo,Hyouk-Sung Kwon,Dong-Hwa Chung 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper proposes the re-configuration of photovoltaic(PV) module considering the environment conditions of the PV system. The PV system is consisted of the series-parallel connection of the PV module. When shadows or changes of the radiation or an electrical characteristic in the solar cell are happened to PV system, the serious power loss will occur. If the PV module connected in series has the shadows, the output current is restricted to current of shaded PV module. Also if shadow is occurred to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, this paper proposes the method that makes the output power of the PV module equalize by reconfiguration of PV module using the switching considering these environment conditions. A validity of the method proposed in this paper proves through comparing with performance of conventional PV module.

ETFE 필름을 적용한 태양광 모듈의 전기적 출력 및 신뢰성에 관한 연구

신우균,임종록,고석환,강기환,주영철,황혜미 한국태양에너지학회 2020 한국태양에너지학회 논문집 Vol.40 No.4

As the supply of photovoltaic (PV) increases worldwide, the cumulative installations in 2018 were 7.9 and 560 GW in Korea and the world, respectively. Typically, when the ground on commercial PV modules is installed, the area is limited; hence, new designs of PV modules are required to install additional PVs. Among the new design of PV modules, lightweight PV modules can be utilized in PV systems, such as buildings, farmlands, and floating PV. Concerning the investigation of lightweight PV modules, several studies on materials for replacing low-iron tempered glass, which comprises approximately 65% of the PV module weight, have been conducted. However, materials that are used as substitutes for glass should possess similar lightweight properties and reliability as glass. In this study, experimental tests were performed to evaluate the applicability of ethylene tetrafluoroethylene (ETFE) film with excellent resistance to water and aging as a front material of PV modules. The transmittance and ultraviolet properties of the ETFE film were determined and compared with those of glass. A 1-cell module and laboratory-scale 24-cell module were manufactured using the ETFE film and glass, and the electrical output was measured and analyzed. Furthermore, damp heat and thermal cycle tests were conducted to evaluate the reliability of the ETFE film module. Based on the experimental results, the electrical output and reliability of the ETFE film module were similar to those of the glass module, and the ETFE film could be used as the front material of PV modules.

태양광 발전시스템의 환경조건을 고려한 PV 모듈 구성

고재섭(Jae-Sub Ko),정동화(Dong-Hwa Chung) 한국조명·전기설비학회 2014 조명·전기설비학회논문지 Vol.28 No.2

This paper proposes the configuration of photovoltaic(PV) module considering the environment conditions of the PV system. The PV system is consisted of the series-parallel connection of the PV module. When shadows or changes of the radiation or an electrical characteristic in the solar cell are happened to PV system, the serious power loss will occur. If the PV module connected in series has the shadows, the output current is restricted to current of shaded PV module. Also if shadow is occurred to the parallel connection PV module, the output voltage is limited to voltage of shaded PV module. These problems are caused power loss. Therefore, this paper proposes the method that makes the output power of the PV module equalize by reconfiguration of PV module using the switching considering these environment conditions. A validity of the method proposed in this paper proves through comparing with performance of conventional PV module.

PV 시스템의 기생 커패시터를 이용한 단선 고장 위치 검출

고재섭,조석환,김금주,김대경 국제차세대융합기술학회 2021 차세대융합기술학회논문지 Vol.5 No.6

본 논문은 PV 시스템에 발생하는 단선 고장의 위치를 검출하는 방법을 제시한다. PV 시스템은 외부에 설치되기 때문에 설치 조건 및 기후환경에 따라 효율이 크게 좌우된다. PV 모듈의 전압 및 용량이 낮기 때문에 원하는 출력을 얻기 위해 다수의 PV 모듈을 연결하여 사용하며 PV 모듈을 연결하는 케이블, 커넥터의 부식 및 연결 불량 등은 PV 모듈의 단선 고장을 유발하여 PV 시스템의 전력손실을 매우 크게 발생시킨다. 또한 케이블, Junction Box 및 단자대 등에서 발생하는 단선 고장은 육안으로 확인되지 않은 경우가 많아, 고장 발생에서 제거 까지 상당한 시간이 소요된다. 본 논문에서는 PV 모듈에 고주파가 주입될 때 나타내는 기생 커패시터를 이용하여 단선 고장의 위치를 검출하는 방법을 제시한다. 기생 커패시터는 유효 표면적에 비례하며, 연결된 PV 모듈의 수 에 따라 비례적으로 증가하는 특징을 가진다. 본 논문은 단선의 위치에 따라 기생 커패시터를 측정하고 그 값을 비교하여 단선 위치를 검출하며, 시뮬레이션을 통한 결과 분석을 통해 타당성을 입증한다. This paper proposes a method for localization of a disconnection fault in a PV system. PV systems are installed outside, their efficiency greatly depends on the installation conditions and climatic environment. Because the voltage and capacity of PV modules are small, multiple PV modules are connected and used to obtain the demanded output. Corrosion and poor connection of cables and connectors connecting PV modules can cause disconnection failure of PV modules, causes a very large loss. In addition, disconnection failures occurring in cables, junction boxes, and terminal blocks are difficult to observe with the naked eye, so it takes a considerable amount of time from occurrence to removal. This paper presents a method for detecting the location of a disconnection fault using a parasitic capacitor that is indicated when a high frequency is injected into a PV module. The parasitic capacitor is proportional to the effective surface area and has a characteristic that increases proportionally according to the number of connected PV modules. This paper measures the parasitic capacitor according to the position of the disconnection, compares the value to detect the disconnection position, and proves its validity through the analysis of the result through simulation.

기계적 하중에 따른 스트레스로 인한 PV 모듈의 전기적 특성

공지현(Kong Ji-Hyun),지양근(Ji Yang-Geun),강기환(Kang Gi-Hwan),유권종(Yu Gwon-Jong),안형근(Ahn Hyung-Geun),한득영(Han Deuk-Young) 한국태양에너지학회 2009 한국태양에너지학회 학술대회논문집 Vol.2009 No.11월

If the Photovoltaic(PV) Module should get physical load, the PV module will be warped according to elongation of the front glass and then micro-crack will be occurred in the heat sealed Solar Cell. This micro-crack drops output of the short circuit current and the open circuit voltage of the PV Module. This is because of increase of resistance component by micro-crack. Micro-crack at specific Solar Cell in the module reduces the durability of PV Module such as less output, Hot-Spot in the PV module caused by Solar Cell output mismatch, heat generating as resistance component caused by micro-crack. In this study, among some factors which effect to the output of crystalline PV Module, we will see how the micro-crack caused by mechanical stress effects to the electrical output of PV Module.

표면냉각시스템을 이용한 PV 모듈의 출력 향상

이종환(Lee Jong-hwan),이재웅(Lee Jae-ung),김동준(Kim Dong-jun),김대현(Kim Dae-Hyun) 한국태양에너지학회 2009 한국태양에너지학회 학술대회논문집 Vol.2009 No.11월

This study was conducted to improve the power of PV module using a surface cooling system. One of the unique characteristics of PV module is power drop as a module surface temperature increases due to the characteristics of crystalline silicon used in a solar cell. To overcome the output power reduction by temperature effect, module surface cooling using water circulation was performed. By cooling effect, module surface temperature drops maximally 20.3℃ predicting more than 10% power enhancement. Maximum deviation of voltage and current between a control and cooled module differed by 5.1V and 0.9A respectively. The maximum power enhancement by cooling system was 12.4% compared with a control module. In addition, cooling system can wash the module surface by water circulation so that extra power up of PV module can be achieved by removing particles on the surface which interfere solar radiation on the cells. Cooling system, besides, can reduce the maintenance cost and prevent accidents as a safety precaution while cleaning works. This system can be applied to the existing photovoltaic power generation facilities without any difficulties as well.