• 한국태양에너지학회 논문집
• /
• 제33권4호
• /
• pp.89-93
• /
• 2013

In recent years, many investigations about photovoltaic power systems have been significantly carried out in the fields of renewable power energy. Such research area generally includes developments of highly efficient solar cells, advanced power conversion systems, and smart monitoring systems. A generic objective of fault detection and diagnosis techniques is to timely recognize unexpected faulty of dynamic systems so that economic demage occurred by such faulty is decreased by means of engineering techniques. This paper presents a novel fault detection approach for photovoltaic power arrays which are electrically connected in series and parallels. In the proposed fault detection scheme, we first measure all of photovoltaic modules located in each array by using electronic sense systems and then compare each measurement in turn to detect location of fault module through statistic computation algorithm. We accomplish real-time experiments to demonstrate our proposed fault detection methodology by using a test-bed system including two 20 watt photovoltaic modules.

• Journal of Power Electronics
• /
• 제14권6호
• /
• pp.1293-1302
• /
• 2014

A flyback inverter using voltage sensorless maximum power point tracking (MPPT) for photovoltaic (PV) AC modules is presented. PV AC modules for a power rating from 150 W to 300 W are generally required for their small size and low price because of the installation on the back side of PV modules. In the conventional MPPT technique for PV AC modules, sensors for detecting PV voltage and PV current are required to calculate the PV output power. However, system size and cost increase when the voltage sensor and current sensor are used because of the addition of the auxiliary circuit for the sensors. The proposed method uses only the current sensor to track the MPP point. Therefore, the proposed control method overcomes drawbacks of the conventional control method. Theoretical analysis, simulation, and experiment are performed to verify the proposed control method.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
• /
• pp.252-256
• /
• 2008

Photovoltaic (PV) modules output changes noticeable with variations in temperature and irradiance. In general it is has been shown that a $1^{\circ}C$ increase in temperature results in a 0.5% drop in output. In this paper, seven PV module types are analyzed for variation in temperature and irradiance, and the resulting output characteristics examined. The 7 modules types utilized are as follows; 3 poly crystalline modules, 2 single crystalline modules, 1 back contact single crystalline module and 1 HIT module. 3 groups of experiments are then conducted on the modules; tests with varying irradiance values, tests with module temperature varying under $25^{\circ}C$ and tests with module temperature varying over $25^{\circ}C$. The experiments results show that as temperature rises the follow is observed; Pmax decreases by 0.6%, Voc decreases by about 0.4%, and Isc increasing by between 0.03%${\sim}$0.08%. In addition, an irradiance decrease of 100 w/m2 translates into a 10% drop in Pmax.

• 한국전기전자재료학회논문지
• /
• 제24권6호
• /
• pp.440-444
• /
• 2011

We have analyzed electrical characteristics of spot light solar cell modules and have completed fabrication of spot light solar cell modules. Before we test modules, we have carried about UV test of hologram. As a result of test, we have obtained 165% efficiency of hologram film. the other hand, we obtained 75% efficiency of general films. After we have fabricated solar modules and carried about field test, spot light solar cell modules with hologram have been investigated 17.3 A of Isc and 155.4 W of power.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
• /
• pp.39-40
• /
• 2005

Photovoltaic Power Generation system occupies an important position as an alternative energy source, converting directly sunlight into electricity,using a photovoltaic cell. The Purpose of this research is to present and confirm the effectiveness of concentration and tracking of sun in photovoltaic power generation. Comparative experiments were carried outwith two rating 75 watt solar modules in $25^{\circ}$ under condition of various times concentration, tracking and plain normal measuring generated voltages, currents and temperatures of back sheet of modules by internet monitoring system to find out which is best in economic sense. The experiments show that output power of concentration and tracking photovoltaic power generation is over 180% more then that of plain normal system.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.28-29
• /
• 2006

When photovoltaic module is used for a long time, its performance decreases due to several reasons. In this paper, we focus on the possibilities mainly contributing to the degraded efficiency of the polycrystalline silicon photovoltaic modules. The analysis is based on the modules that have been used for 15 years. These are two main reasons that cause the efficiency degradation, the corrosion and thermal decomposition. The former phenomenon of electrode is mainly due to the moisture from damaged back sheet in some module. However the other reason of the degraded efficiency comes from the thermal decomposition, which can not be observed from the outside but only by experiment. In this study, the comparison between the efficiency of normal modules and degradation modules is presented. Module having degraded cell was seen to cause increase of series resistance by about 80%, in comparison to normal samples efficiency which reduce by about 20%. This study shows that the effects of series resistances on module performance are critical. These effects must be understood and taken into consideration when analyzing performance degradation.

• 한국태양에너지학회 논문집
• /
• 제40권5호
• /
• pp.1-12
• /
• 2020

To assess the performance and characteristics of colored building-integrated photovoltaic (BIPV) modules, a comparative assessment of empirical performance was conducted on colored BIPV modules (gray, blue, and orange) and general BIPV module. These modules were installed on the south-facing slope (30°) for comparative assessment through a field test. Monitoring data were collected every 10 min from December 20, 2019 to January 21, 2020 and used to performance and characteristics analysis. Performance ratio and module efficiency were utilized during performance indexing for comparative assessment. For general BIPV modules, the operational efficiency was analyzed at 16.63%, whereas for colored BIPV modules, 13.70% (gray), 15.12 % (blue), and 14.49% (orange) were analyzed. It was discovered that the efficiency reduction caused by transmission losses owing to the application of colored cover glasses were 17.74% (gray), 9.05% (blue), and 9.86 % (orange), under field testing conditions. These values turned on an additional 7% reduction in efficiency for gray BIPV modules, compared to the degradation resulting from transmission drop (gray: 10.87%, blue: 8.99%, and orange: 9.02%) calculated using the efficiency of each module in standard test conditions (STC). Performance ratio analysis resulted in the following values: 0.92 for general BIPV modules, and 0.85 (gray), 0.91 (blue), and 0.91 (orange) for colored BIPV modules. As demonstrated by the above results, modules with a colored cover glass may differ in their operational performance depending on their color, unlike general modules. Therefore, in addition to the performance evaluation under STC, additional factors of degradation require consideration through field test.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
• /
• pp.303-308
• /
• 2009

In 2008, the global photovoltaic(PV) market reached 5.6GW and the cumulative PV power installed totalled almost 15GW compared to 9GW in 2007. Due to a favourable feed-in-tariff, Korea emerged in 2008 as the 4th largest PV market worldwide. PV power installation rose 495.5 percent to 268MW in 2008 compare to 45MW in 2007. However many PV systems are not installed in suitable part which is concerned about geometrical factor. It is generally recognized that the actual output of PV system in field is a function of orientation, tilt angle, irradiance, temperature, soiling and various system-related losses. Thus this paper shows that a experimental result of PV modules(A group) with uniform azimuth angle and PV modules(B group) with non-uniform azimuth angle. As a result, the electrical output of B group is decreased 48.8% as compared with electrical output of A group.

• Journal of Power Electronics
• /
• 제13권2호
• /
• pp.296-303
• /
• 2013

This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.64-64
• /
• 2010

This paper presents the results of changes of optical properties of front materials in crystalline PV modules. If PV modules on the outdoor, transmittance of front materials is reduced by solar light. That is UV, IR included Solar spectrum will have change the properties of glass. Therefore decrease in transmittance leads to loss of the PV modules output. All the PV modules showed the loss in Isc by 1~5% within few hors. To investigate the changes we are analyzed using spectrophotometer from raw glass to laminated glass.