• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.334-336
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• 2001

The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller PLL control system and the phase detector of interactive voltage by using do transformation. The proposed inverter system provides a sinusoidal are current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1584-1592
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• 2015

This paper presents a nonlinear method to control a DC-DC converter and track the Maximum Power Point (MPP) of a Photovoltaic (PV) system. A backstepping controller is proposed to regulate the voltage at the input of a buck-boost converter by means of Lyapunov functions. To make the control initially faster and avoid local maximum, a regression plane is used to estimate the reference voltages that must be obtained to achieve the MPP and guarantee the maximum power extraction, modifying the conventional Perturb and Observe (P&O) method. An experimental platform has been designed to verify the validity and performance of the proposed control method. In this platform, a buck-boost converter has been built to extract the maximum power of commercial solar modules under different environmental conditions.

• Current Photovoltaic Research
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• v.10 no.4
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• pp.116-120
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• 2022

Solar energy is rapidly being utilized to generate power in Europe and other countries, but the environmental effect of building and operating solar farms is not fully understood. The building of a solar park demands the removal of certain vegetation and the leveling of the land. Solar energy infrastructure may involve considerable landscape change, altering soil biological processes and influencing hydrologic, carbon and vegetative dynamics. To rebuild the solar PV facilities soils, inherent plant fields might require to be re-established. Within the scope of this research, we presented an analysis of the effects that were caused by the solar farm.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.471-477
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• 2012

In this paper, in order to use module integrated converter using cascaded buck-boost converter for a low battery charger in stand-alone system, a charging algorithm which considers photovoltaic and battery status and PWM controllers which are changed according to charging modes are proposed. The proposed algorithm consists of constant current mode, constant voltage mode and maximum power point tracking mode which enables the battery to charge with maximum power rate. This paper also presents design of cascaded buck-boost converter that is the photovoltaic charger system. A 150W prototype system is built according to verify proposed the charger system and the algorithm.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.11-19
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• 2015

Islanding is a phenomenon that EPS(Electric Power System) is continuously energized by PV PCS(Photovoltaic Power Conditioning System) even when EPS is isolated from the grid. Unintentional islanding will result in safety hazard, power quality degradation and many other issues. So, islanding protection of grid-connected PV PCS is a key function for standards compliance. Nowadays, many anti-islanding schemes are researched. But existing anti-islanding schemes used in PV PCS have power quality degradation and non-detection zone issues. This paper analyses not only detection performance of existed anti-islanding schemes using active frequency drift but also THD of PCS output current according to each value disturbance for anti-islanding. In addition, the lowest value of disturbance in each scheme was tabulated under guarantee of anti-islanding condition.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1386-1387
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• 2011

Maximum power point tracking(MPPT) techniques are used in photovoltaic systems to maximize the PV array output power by tracking continuously the maximum power point which depends on panels temperature and on irradiance conditions. In this paper, the controller of the stand-alone PV system applicable to various fields are designed. The improved P&O MPPT and traditional P&O MPPT method was applied. This improved algorithm consists of a constant perturbation with an step control which will make easier the controller PV power data acquisition process. This strategy of control has, in first time, been validated by PSIM simulations. After, been field test. The experimental results show that the improved P&O method increased the PV output power compare to traditional P&O method.

• New & Renewable Energy
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• v.10 no.3
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• pp.39-46
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• 2014

The performances of three different types of photovoltaic (PV) module technologies namely, copper-indium-diselenide (CIGS), mono-crystalline silicon (mo-Si) and amorphous silicon (a-Si) have been comparatively studied in the grid-connected system for more than a year under the tropical monsoon climate of Thailand. The yields, performance ratios and system efficiencies for the respective PV module technologies have been calculated and a comparison is presented here. The performance ratios of the initial operation year for CIGS showed highest among the compared technologies under Thailand climate conditions by marking 97.0% while 89.6% for a-Si and 81.5% for mo-Si. Although mo-Si has shown highest efficiencies all over the period, under the testing conditions, the operating efficiency of mo-Si was down-graded from its reference value mainly due to high operating temperature and the efficiency of the tested CIGS module was also found as high as that of mo-Si in the study. Accordingly, outdoor assessment shows that CIGS modules have demonstrated high performance in terms of yields and performance ratios in Thailand climate conditions.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1051_1052
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• 2009

This paper deals with operational characteristic analysis of a single-phase PCS (Power Conditioning System) for PV (Photovoltaic) power generation system with AF (Active Filter) function. The theory of dq transformation has been applied to the control strategy of a single-phase PV power generation system to implement the AF function. Application of the virtual two-phase using phase-shift makes it possible to use the dq theory for the single-phase PV power generation system. The authors are sure that the proposed system is a very useful to compensate harmonics caused by nonlinear loads in a single-phase utility system. In this paper, not only a theoretical aspect of the single-phase PV-AF system is discussed, but also the DSP (Digital Signal Processor) based experiment results are presented to demonstrate the effectiveness of the single-phase PV-AF system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.42-49
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• 2012

Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.2
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• pp.171-177
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• 2002

The Photovoltaic systems with solar cell way Provide electrical energy to the utility/consumers, which are becoming one of the promising energy substitutes. The photovoltaic system can be classified into two types : One is the stand-alone type, and the other utility interactive one. The latter can return the generated power to the utility, but the former can't. The utility interactive systems are so valuable for peak power cut in summer season. In the photovoltaic systems the maximum power point tracking (MPPT) has been studied for the increase of the generating energy of the photovoltaic system. There are many control methods of MPPT, but a new MPPT algorithm is proposed to overcome the disadvantages of the conventional ones, and as a result the proposed method enables to improve both tracking ability and generating efficiency of photo voltaic system without DC chopper.