• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.216-223
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• 2018

Since solar cells have non-linear voltage-current output characteristics, Photovoltaic systems require the Maximum Power Point Tracking(MPPT) function. For this reason, a large number of MPPT techniques have been studied. However, the conventional MPPT techniques may fail to track the maximum power point when partial shading occurs in the solar cell array due to its characteristics. Therefore, it is necessary to research the MPPT technique that can follow the maximum power point in the partial shadow condition. In this paper, the characteristics of solar cell arrays in partial shadowing are analyzed and the MPPT technique which can follow the maximum power point in partial shadow condition has been proposed. To validate the proposed MPPT method, simulation and experimentation results are provided.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.540-542
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• 1996

A detailed model of a photo voltaic array written in PSPlCE is presented in this paper. It is likely that solar cell arrays in photovoltaic system is shadowed partly by clouds, buildings. By the effects of partial shadowing, not only the output power of solar cell arrays is decreased, but also shadowed cells are reversely biased and damaged in some cases. In this paper, by analyzing the output characteristics of solar cell arrays according to various shadow patterns, we investigate solar cell arrays connection of prevention the shadowing effects to the utmost.

• Current Photovoltaic Research
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• v.4 no.2
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• pp.64-67
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• 2016

We investigated the influences of Ag nanoparticle (NP) arrays and surface nanohole (NH) patterns on the optical characteristics of 10-${\mu}m$-thick c-Si wafers using finite-difference time-domain (FDTD) simulations. In particular, we comparatively studied the plasmonic effects of both monomer arrays (MA) and heptamer arrays (HA) consisting of identical Ag NPs. HA improved the optical absorption of the c-Si wafers in much wider wavelength range than MA, with the help of hybridized plasmon modes. The light trapping capability of the NH array pattern is superior to that of the Ag plasmonic NPs. We also found that the addition of the Ag HA on the wafers with surface NH patterns further enhanced optical absorption: the expected short-circuit current density was as high as $34.96mA/cm^2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.440-440
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• 2009

Semiconductor nanowires offer exciting possibilities as components of solar cells and have already found applications as active elements in organic, dye-sensitized, quantum-dot sensitized, liquid-junction, and inorganic solid-state devices. Among many semiconductors, silicon is by far the dominant material used for worldwide photovoltaic energy conversion and solar cell manufacture. For silicon wire to be used for solar device, well aligned wire arrays need to be fabricated vertically or horizontally. Macroscopic silicon wire arrays suitable for photovoltaic applications have been commonly grown by the vapor-liquid-solid (VLS) process using metal catalysts such as Au, Ni, Pt, Cu. In the case, the impurity issues inside wire originated from metal catalyst are inevitable, leading to lowering the efficiency of solar cell. To escape from the problem, the wires of purity of wafer are the best for high efficiency of photovoltaic device. The fabrication of wire arrays by the electrochemical etching of silicon wafer with photolithography can solve the contamination of metal catalyst. In this presentation, we introduce silicon wire arrays by electrochemical etching method and then fabrication methods of radial p-n junction wire array solar cell and the various merits compared with conventional silicon solar cells.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.135-141
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• 2008

In this paper a novel tracking system is described, regarding the influence of shadow between array, aimed at improving the efficiency of PV tracking system. Comparing with a building site versus capacity power, domestic solar powers have a limited siting. Therefore, each array interferes with the shadow of other arrays. The loss by influence of those shadow can be compensated for by means of control algorithm of the tracking device. The paper suggests a method controlling an altitude for length which is received the shadow influence of PV array. By using an azimuth of current solar position and the length between arrays, the controller of tracking device is able to calculate the length between actual arrays and make a comparison of the shadow length at a specific time with the length between arrays. When the shadow length is longer than the length between arrays, the controller of tracking device can adjust a position by compensating error altitude of the length between arrays at an altitude of current solar position. In the paper, we develop the control algorithm able to minimize the loss caused by the influence of shadow on the PV tracking system, and compared this with conventional output system. The controller has been tested in the laboratory with proposed algorithm and shows excellent performance

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.524-529
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• 2012

This paper proposes a novel control strategy of a PV tracking system considering the shadow influence. If distance of between PV arrays is not enough, shadow can be occurred to PV module. In PV system, if shadow is occurred to PV modules then PV modules operates reverses bias, and will eventually cause hot-spot and loss. To reduce loss by shadow influence, this paper proposes shadow compensation algorithm using distance between arrays and shadow length of array. The distance between arrays is calculated by using azimuth of solar, and length of array shadow is calculated using by altitude of solar. The shadow compensation algorithm proposed in this paper compares distance between arrays and length of array shadow. When the shadow length is longer than the distance between arrays, the algorithm adjusts altitude of array to avoid the shadow effects. The control algorithm proposed in this paper proves validity through compared with conventional algorithm and proposes experiment result.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1489-1500
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• 2018

Partial shading analysis of large-scale photovoltaic (PV) arrays has recently become a theoretically and numerically challenging issue, and it is necessary for PV system designers. The main contributions of this study are the following: 1) A PSIM-based macro-model was employed because it is remarkably fast, has high precision, and has no convergence issues. 2) Three types of equivalent macro-models were developed for the transformation of a small PV sub-array with uniform irradiance to a new macro-model. 3) On the basis of the proposed new macro-model, a tearing method was established, which can divide a large-scale PV array into several small sub-arrays to significantly improve the efficiency improvement of a simulation. 4) Three platforms, namely, PSIM, PSpice, and MATLAB, were applied to evaluate the proposed tearing method. The proposed models and methods were validated, and the value of this research was highlighted using an actual large-scale PV array with 2420 PV modules. Numerical simulation demonstrated that the tearing method can remarkably improve the simulation efficiency by approximately thousands of times, and the method obtained a precision of nearly 6.5%. It can provide a useful tool to design the optimal configuration of a PV array with a given shading pattern as much as possible.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.92-94
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• 2008

This paper introduces the modeling of grid-connected photovoltaic(PV) generation using Matiab/Simulink. The model is based on the equivalent circuit of the PV solar cell including the effects of solar irradiation and temperature changes. The PV arrays are modeled to be built up with the series/parallel combination of PV solar cell and are connected to the distribution system via an inverter. The simulation results show that the typical characteristics and outputs of the PV arrays are accurate.

• Current Photovoltaic Research
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• v.2 no.4
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• pp.189-194
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• 2014

In this paper, We have simulated the output variation of the PV arrays installation with position & angle change. The existing 3 solar array system are $43^{\circ}$ southeast and each of the mounting angle is $17^{\circ}$. The PV output power is 240 kW. The composite studied systems in this paper arrays altered 2 PV array among 3 PV array system- the output 144kW. We simulated this system using Solar Pro ver.4.1. The simulation conditions are southwest $43^{\circ}/array$, mount angle $27^{\circ}/array$. Because the southeast have shadow effect-higher mountain The purpose of southwest $43^{\circ}$ is reduce the shadow effect. The simulation results of the suggestion design algorithm compared to 1,590 kWh/year output is increased with the southeast.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.10-13
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• 2000

This paper proposes the virtual implementation of solar cell(VISC) for photovoltaic system. It is required to make operation condition of solar cell arrays where is the limit of time and space, The main advantage of the simulator is its ability to simulate different types and sizes of arrays considering V-I characteristics of data sheet. The VISC with buch-boost converter can be used to study the short-term and long-term performances of PV cells. The simulator is a far more cost effective and reliable replacement for field and filight testing.