• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.977-983
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• 2013

Based on the consideration of the hourly patterns of the electricity power consumption, this study predicted the effectiveness of hybrid power generation system, which is composed with wind power generator and photovoltaic generator. And this case study is performed at Konrido, which is a affiliated island of Kyeongsangnam-do. As the results, it is obvious that it is not efficient to cover the whole electricity power consumption only with any single power generating system, because the hourly patterns of electricity power consumption, wind power generation and photovoltaic generation are quite different. And because the wind is being through almost 24 hours, it is also found out that wind power generating system with storage battery is the most efficient combination for this case study.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.117-118
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• 2013

Recent global warming to the promotion of electric vehicles (EV), plug-in hybrid (PEV), including the next generation of cars and solar power, wind power and other renewable energy, and next-generation power grid (smart grid) are getting attention. In addition, the system utilizes the battery life in the industry and the convenience of a variety of social systems, economics, environmental impact, and the inherent potential to change significantly, and you can not walk into a next-generation industrial strategy and the need increases more and more present, and its early commercialization In order to do this, as well as a key energy source, the battery charger for charging efficiency technologies is essential. In this paper, fast charge multiple battery modules and optional modules that can charge distribution charge will be introduced.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.533-536
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• 2005

In this paper, a new drive system(SHS) for hybrid electric vehicle is proposed. As dual rotor hybrid electric vehicle using planetary gearsets, the SHS has the advantages of both series and parallel systems. The output speed and torque of SHS can be determined at specific point regardless of the engine's operating point. When the size of generator which is used in SHS is same as in THS, the SHS has more activities of engine control due to the ability that is operated in lower speed range. To maximize the performance of system, we carried out optimization for the three parameters that are engine, motorl and motor2. As the result of the optimization, we confirmed the SHS is more preferable to THS in fuel consumption and acceleration area.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.606-619
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• 2018

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1483-1493
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• 2018

Recently, more power facilities are needed to cope with the increasing electric demand. However, the additional construction of generators, transmission and distribution installations is not easy because of environmental problems and citizen's complaints. Under this circumstance, a microgrid system with distributed renewable resources emerges as an alternative of the traditional power systems. Moreover, the configuration of power system changes with more DC loads and more DC installations. This paper is written to introduce an idea of a genetic algorithm-based solution to determine the optimal capacity of the distributed generators depending on the types of system configuration: AC-link, DC-link and Hybrid-link types. In this paper, photovoltaic, wind turbine, energy storage system and diesel generator are considered as distributed generators and the feasibility of the proposed algorithm is verified by comparing the calculated capacity of each distributed resource with HOMER simulation results for 3 types of system configuration.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.6
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• pp.449-469
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• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.367-374
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• 2013

The electrical vehicles (EV) with vehicle-to-grid (V2G) capability can be used as loads, energy sources and energy storage in MicroGrid integrated with renewable energy sources. The output power of generators will be reallocated in the considering of V2G. An intelligent unit commitment (UC) with V2G for cost optimization is presented in this paper. A new constraint of UC with V2G is considered to satisfy daily use of EVs. A hybrid optimiza-tion algorithm combined Binary Particle Swarm Optimization (BPSO) with Lagrange Mul-tipliers Method (LMM) is proposed. The difference between results of UC with V2G and UC without V2G is presented.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.84.1-84.1
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• 2010

Currently, new and renewable energy come into the spotlight, such as solar energy, wind power, fuel cell, hybrid car etc., due to the energy resource is being depleted. Especially, in order to solve like this problem, the study of solar cell manufacturing systems are being extensively researched such as vacuum process. But the major fault of the vacuum process are its expensive production price. On the order hand, Roll-to-roll printing system, the new technology of solar cell manufacturing, has low production price compare with the vacuum process. Also roll-to-roll printing system can decrease the 95% of waste water and 99.9% of harmful gasses than the vacuum process. So we addressed the roll to roll printing system for the flexible solar cell by using printing technology. This roll-to-roll printing system is comprised of various modules, such as web handling module, fine pattern printing module, dry/curing module, uniform coating module and laminating module etc.

• Journal of Power Electronics
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• v.16 no.1
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• pp.153-162
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• 2016

Given their structural arrangement, photovoltaic (PV) modules exhibit parasitic capacitance, which creates a path for high-frequency current during zero-state switching of the converter in transformerless systems. This current has to be limited to ensure safety and electromagnetic compatibility. Many solutions that can minimize or completely avoid this phenomenon, are available. However, most of these solutions are patented because they rely on specific and often complex converter topologies. This study aims to solve this problem by introducing a solution based on a classic converter topology with an appropriate modulation technique and passive filtering. A 5.5 kW single-phase residential PV system that consists of DC-DC boost stage and DC-AC H-bridge converter is considered. Control schemes for both converter stages are presented. An overview of existing modulation techniques for H-bridge converter is provided, and a modification of hybrid modulation is proposed. A system prototype is built for the experimental verification. As shown in the study, with simple filtering and proper selection of switching states, achieving low leakage current level is possible while maintaining high converter efficiency and required energy quality.

• Journal of Ocean Engineering and Technology
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• v.30 no.1
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• pp.57-67
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• 2016

As a new technical approach, an attempt was made to realize a photovoltaic system for an eco-environmental leisure ship by simultaneously actuating nine photovoltaic solar panels in association with the application of a sail-controlling system using wind energy. In this approach, the photovoltaic system consisted of a solar module, an inverter, a battery, and the relevant components, while the sail-controlling device was equipped with sail up/down and mast turning systems. The previously mentioned eco-environmental leisure ship utilizes a photovoltaic hybrid system that uses solar and wind energy as renewable energy sources. Furthermore, this research included a performance evaluation of the manufactured prototype, the acquisition of the purposed quantity values, and development of the purposed items. The significant items, including the sail up/down speed (seconds) and mast turning angle (degrees) were evaluated for a performance test. A wind direction sensitivity of 90% and maximum instant charging power of 900 W were also obtained in the process of the performance evaluation. In addition, the maximum sail time was also evaluated in order to acquire the optimum value. The performance evaluation showed that the prototype with a photovoltaic hybrid system was suitable for sailing an eco-environmental leisure ship using solar and wind energy.