• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2177-2180
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• 1997

The solar cell has an optimum operating point to be able to got maximum power. To obtain maximum power from Photovoltaic array, hotovoltaic power system usually requres maximum power point c tracking controller. The output characteristics of solar cell are nonlinear, and these characteristics vary with load solar insolation, solar cell temperature. Therefore the tracking control of maximum power point is the com-plicated problem. This paper presents power characteristics of residential Photovoltaic system applying a buck-boost conversion system.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.413-415
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• 1997

The solar cell has an optimum operating point to be able to get maximum power. To obtain maximum power from Photovoltaic array, potovolt aic power syste usually requres maximum power point tracking controller. The output characteristics of solar cell are nonlinear, and these characteristics vary with load solar insolation, solar cell temperature. Therefore the tracking control of maximum power point is the complicated problem. This paper presents power characteristics of residential Photovoltaic system applying a quck-boost conversion system.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.301-302
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• 2007

Maximum power consumption was up to 6,228kW in the summer of 2007 due to steady development of industry as well as increased demand of individual. Twenty fossil-Fired Thermal Power Plant for 500MW were underconstructed at present. KEPRI(Korea Electric Power Research Institute) manage 'Development of Advanced Fossil-Fired Thermal Power Generation System' project to construct high efficient power plant of 1000MW capacity for preparing increased demand of power. Design of control logic and data sampling were explained and high efficient control logic was simulated in detail in 'The Development of Next Generation Power Plant Instrument and Control System'(sub-project of 'Development of Advanced Fossil-Fired Thermal Power Generation System' project).

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.40-44
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• 2018

In this paper, the efficiency of the solar system is lowered due to the partial shading such as the environmental factors of the solar panel. In order to solve this problem, a DC OPTIMIZER is proposed for a maximum power generation system of a photovoltaic panel. The proposed DC OPTIMIZER is composed of a buck structure that performs the maximum power point tracking (MPPT) control of each module of the solar panel, thus maximizing the efficiency. In order to verify the proposed DC Optimizer, the efficiency was measured by varying the irradiance using a solar simulator instead of the solar panel. As a result, it showed high efficiency characteristics as the maximum energy conversion efficiency was 99.3% at $800w/m^2$, $900w/m^2$, and the average efficiency was 99.06% excluding $100w/m^2$. The maximum efficiency of MPPT was 99.97% at $200w/m^2$, efficiency showed excellent performance.

• Environmental Engineering Research
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• v.22 no.2
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• pp.157-161
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• 2017

Simultaneous treatment of food waste leachate and power generation was investigated in an air-cathode microbial fuel cell. A TCOD removal efficiency of $95.4{\pm}0.3%$ was achieved for an initial COD concentration of 2,860 mg/L. Maximum power density ranged was maximized at $1.86W/m^3$, when COD concentration varied between 60 mg/L and 2,860 mg/L. Meanwhile, columbic efficiency was determined between 1.76% and 11.07% for different COD concentrations. Cyclic voltammetric data revealed that the oxidation peak voltage occurred at -0.20 V, shifted to about -0.25 V. Moreover, a reduction peak voltage at -0.45 V appeared when organic matters were exhausted, indicating that reducible matters were produced during the decomposition of organic matters. The results showed that it was feasible to use food waste leachate as a fuel for power generation in a microbial fuel cell, and the treatment efficiency of the wastewater was satisfied.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.271-273
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• 2005

In KEPCO(Korea Electric Power Corporation)system, 40% of total loads is ones of metropolitan area and large staled generation plants are located out of metropolitan area. Therefore, to decide the maximum power transfer capability of interface line between the regions is essential for planning, control and operation of efficient transmission system. For this reason, prior study suggested calculating the limit of our interface line from the side of voltage stability. However, the presented plan had a limit partially to apply practice power system. Therefore this paper suggests a algorithm that change the generation output as the merit order instead of prior method that distribute according to proportion of present output. This method could be applied closer to practice than the existing algorithm because it consider generation cost.

• Journal of Climate Change Research
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• v.9 no.2
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• pp.197-207
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• 2018

The Korean government views coal-fired power plants as the key cause of the fine dust generation, and is developing an energy policy to replace and demolish old coal-fired power plants. According to the Eighth Power Supply Base Plan (2017-2031), the maximum power capacity in 2030 is expected to be 100.5GW, which is 17.9% higher than the current level (85.2GW). The plan aims to reduce the facility size and power generation ratio from nuclear and coal resources to even lower levels than today, and to rapidly expand power generation from new and renewable energy. Despite that, the proportion of coal power generation is still much higher than other resources, and it is expected that the reliance on goal will maintain for next several decades. Under such circumstances, the development, supply, and expansion of clean coal technology (CCT) that is eco-friendly and highly efficient, is crucial to minimize the emission of pollutants such as carbon dioxide and fine dust, as well as maximize the energy efficiency. The Korean government designated the Yong-Dong Thermoelectric Power Plant in Gangneung to develop clean coal power generation, and executed related projects for three years. The current study aims to suggest a plan to develop parts, technologies, testing, evaluation, certification, and commercialization efforts for coal-fired power generation, In addition, the study proposes a strategy to vitalize local economy and connect the development with creation of more jobs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.182-187
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• 2018

In this study, 20.8% of a p-type Si bifacial solar cell was used to develop a photovoltaic (PV) module to obtain the maximum power under a limited installation area. The transparent back sheet material was replaced during fabrication with a white one, which is opaque in commercial products. This is very beneficial for the generation of more electricity, owing to the additional power generation via absorption of light from the rear side. A new model is suggested herein to predict the power of the bifacial PV module by considering the backside reflections from the roof and/or environment. This model considers not only the frontside reflection, but also the nonuniformity of the backside light sources. Theoretical predictions were compared to experimental data to prove the validity of this model, the error range for which ranged from 0.32% to 8.49%. Especially, under $700W/m^2$, the error rate was as low as 2.25%. This work could provide theoretical and experimental bases for application to a distributed and microgrid network.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.69-72
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• 2003

The paper presents implementation of a PV fuzzy logic power tracking controller. Using maximum power point tracker with the intermediate converter can increase the system efficiency by matching the PV system to the load. A new fuzzy MPPT is proposed, where fuzzy inputs parameters are dp/dI and the last incremental of duty of duty ratio $L{\delta}D$, and the output is the new incremental value $(new{\delta}D)$ according to the maximum power point under various illumination levels.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.5
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• pp.376-383
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• 2022

The improved performance of computer parts, such as graphic card, CPU, and main board, has led to the need for power supplies with a high power output. The dynamic load profile rapidly changes the usage of power consumption depending on load operations, such as PC power and air conditioner. Under dynamic load profile conditions, power consumption can be classified into maximum, normal, and standby power. Several problems arise in the case of maximum power. Peak power is generated at the system power source in the maximum-power situation. Frequent generation of peak power can cause high-frequency problems and reduce the life of high-pressure parts (especially high-pressure capacitors). For example, when a plurality of PCs are used, system overload occurs due to peak power generation and causes problems, such as power failure and increase in electricity bills due to exceeded contract power. To solve this problem, a system peak power limit/compensation power circuit is proposed for a power supply under dynamic load profile conditions. The proposed circuit detects the system current to determine the power situation of the load. When the system current is higher than the set level, the circuit recognizes that the system current generates peak power and compensates for the load power through a converter using a super capacitor as the power source. Thus, the peak power of loads with a dynamic load profile is limited and compensated for, and problems, such as high-frequency issues, are solved. In addition, the life of high-pressure parts is increased.