• Nuclear Engineering and Technology
• /
• v.40 no.3
• /
• pp.183-190
• /
• 2008

Pyroprocessing is the optimal means of treating spent metal fuels from metal fast fuel reactors and is proposed as a potential option for GNEP in order to meet the requirements of the next generation fuel cycle. Currently, efforts for research and development are being made not only in the U.S., but also in Asian countries. Electrorefining, cathode processing by distillation, injection casting for fuel fabrication, and waste treatment must be verified by the use of genuine materials, and the engineering scale model of each device must be developed for commercial deployment. Pyroprocessing can be effectively extended to treat oxide fuels by applying an electrochemical reduction, for which various kinds of oxides are examined. A typical morphology change was observed following the electrochemical reduction, while the product composition was estimated through the process flow diagram. The products include much stronger radiation emitter than pure typical LWR Pu or weapon-grade Pu. Nevertheless, institutional measures are unavoidable to ensure proliferation-proof plant operations. The safeguard concept of a pyroprocessing plant was compared with that of a PUREX plant. The pyroprocessing is better adapted for a collocation system positioned with some reactors and a single processing facility rather than for a centralized reprocessing unit with a large scale throughput.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.761-767
• /
• 2001

In this paper, filtering techniques to reduce the adverse effects of motor leads on high-frequency PWM inverter fed AC motor drives will be examined. The filter was designed to keep the motor terminal from the cable surge impedance to reduce overvoltage reflections, ringing, and the dv/dt, di/dt. Therefore, filtering techniques are investigated to reduce the motor terminal overvoltage, ringing, and EMI noise in inverter fed ac motor drive systems. The output filter is used to limit the rate of the inverter output voltage and reduce EMI(common mode noise) to the motor. The performance of the output filter is evaluated through simulations (PSIM) and experiment on PWM inverter-fed ac motor drive(3phase, 3hp(2.2kw), input voltage 220/380V, induction motor). An experimental PWM drive system reduction of conducted EMI was implemented on an available TMS320C31 microprocessor control board. Finally, experimental results showed that the inverter output filter reduces more CM noise than the LPF(low pass filter) and reduce overvoltage and ringing at the motor terminal.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.988-990
• /
• 2000

This paper presents the software control of a brush-less DC motor. Not only speed and current controls but also a real-time identification of the motor parameters can be implemented by software using the digital signal processor (DSP) TMS320F240. The DSP Controller TMS320F240 from Texas Instruments is suitable for a wide range of motor drives. TMS320F240 provides a single chip solution by integrating on-chip not only a high computational power but also all the peripherals necessary for electric motor control. The main benefits are increased system reliability and cost reduction of the overall system. The present paper describes how a speed controlled brushless DC drive can be implemented using TMS320F240.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.2
• /
• pp.215-222
• /
• 2023

Alternative marine power (AMP) is continuously used in ports and on docks because of regulations on global ship emission reduction. In Korea, the use of AMP is also mandatory under the Special Act on Port Air Quality Improvement, and efforts are under way in connection with various eco-friendly ships, such as electric-propulsion ships. In this study, AC load flow analysis was performed by modeling the situation in which onboard power is supplied through AMP. This analysis made it possible to study the electrical parameters and losses when power was supplied to the ship. In addition, through a transient stability analysis, the high-speed generation transfer limit value for uninterruptible conversion through onboard generators in the event of a system accident was derived. The results obtained when it was applied are presented

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.1
• /
• pp.103-108
• /
• 2016

Carbon Capture and Storage technologies are recognized as key solution to meet greenhouse gas emission standards to avoid climate change. Although MEA (monoethanolamine) is an effective amine solvent in $CO_2$ capture process, the application is limited by high energy consumption, i.e., reduction of 10% of efficiency of coal-fired power plants. Therefore the development of new solvent and improvement of $CO_2$ capture process are positively necessary. In this study, improvement of $CO_2$ capture process was investigated and applied to Test Bed for reducing energy consumption. Previously reported technologies were examined and prospective methods were determined by simulation. Among the prospective methods, four applicable methods were selected for applying to 0.1 MW Test Bed, such as change of packing material in absorption column, installing the Intercooling System to absorption column, installing Rich Amine Heater and remodeling of Amines Heat Exchanger. After the improvement construction of 0.1 MW Test Bed, the effects of each suggested method were evaluated by experimental results.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.459-465
• /
• 2007

This study was conducted to calculate the LCC of a apartment complex with a type of heating system, district heating and cogeneration system. For the purpose of analyzing LCC according to size of apartment complex, 500, 1,500 and 4,000 houses of model apartment selected. This research performs design of heating system and the life cycle cost analysis including an initial cost, energy cost, maintenance and operation cost, replacement cost and renovation cost during the project period(15years). According to the calculated results, 1) Initial cost of cogeneration system with 500, 1500 and 4000 houses is higher than district heating system each of 20%, 13%, 12%. 2) In case of cogeneration system, the payback period by electric generation is 5.21, 4.92 and 4.47 years and saving cost was calculated 29 billion won, 94 billion won and 262 billion won after payback period. 3) Cogeneration system LCC was 1.12, 1.07 and 1.06 times larger than district system with the size of apartment complex. According to the case of this study district heating system is more efficient than cogeneration system in terms of the reduction of LCC. 4) Gas Engine Co-generation System is more efficient than other systems because it can collect progressive part from electric charge progressive stage system. However, the efficiency is decreasing because of raising of fuel bills(LNG) and lowering of power rate for house use. Especially the engine is foreign-made so the cost of maintenance and repair is high and the technical expert is short. 5) District heating is also affected by fuel bills so we should improve energy efficiency through recovering of waste heat(incineration heat, etc.). Also, we should supply district cooling on the pattern of heat using of let the temperature high in winter and low in summer.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.7
• /
• pp.945-952
• /
• 2019

The International Maritime Organization (IMO) adopted the International Convention on the Control of Ships' Air Pollutants and Discharge as it became interested in environmental issues such as global warming and air pollution. In addition, a special bill on the improvement of air quality, including in port areas, has recently been enacted in Korea to reduce the amount of fine dust generated. As part of such fine dust reduction measures, feasibility studies have been underway on converting diesel engines into battery electric propulsion systems that do not cause fine dust and emissions. Since the battery electric propulsion system can easily utilize renewable energy sources, and does not generate exhaust gas due to combustion of fuel, small coastal ferries with battery electric propulsion systems that use renewable energy have been operating in Europe and the U.S. for several years. However, they have not been introduced in Korea. Therefore, in this study, we selected small coastal ferries in Korea as target ferries, and performed simulations to study the applicability of electric propulsion with batteries linked to solar power systems. Based on the results, we want to confirm the applicability of battery electric propulsion.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.6
• /
• pp.1183-1194
• /
• 2021

Traditionally, electric power systems have been known as the centralized structures, which is organized into placing customers at the end of the supply chain. However, recent decades have witnessed the emergence of distributed energy resources(:DERs) such as rooftop solar, farming PV system, small wind turbines, battery energy storage systems and smart home appliances. With the emergence of distributed energy resources, the role of distributed system operators(:DSOs) will expand. The increasing penetration of DERs could lead to a less predictable and reverse flow of power in the system, which can affect the traditional planning and operation of distribution and transmission networks. This raises the need for a change in the role of the DSOs that have conventionally planned, maintained and managed networks and supply outages. The objective of this research is to designed the future distribution operation system with multi-DERs and the proposed distribution system model is implemented by hardware-in-the-loop simulation(HILS). The test results show the normal operation domain and reduction of distribution line loss.

• Journal of the Korean Magnetics Society
• /
• v.25 no.6
• /
• pp.189-197
• /
• 2015

As enforced the regulation of fuel efficiency, the electrification of automotive components in internal combustion vehicle has been applied instead of hydraulic pressure. A typical example of such parts is the EPS (electric power steering), and it is applied to most automotive at present. In electric power steering system, the core component is motor. The reduction of cogging torque and torque ripple is required to improve steering feeling and reduce NVH (Noise Vibration Harshness) in EPS. Generally the skewed design of stator or rotor is applied in order to reduce cogging torque and torque ripple. This paper propose the design and analysis methodology of Brusheless PMSM (Permanent Magnet Synchronous Motor) which is applied to skewed stator. The proposed methodology is as follows: First Intial Design PMSM with skewed stator for EPS, Second Optimal design using RSM (Response surface method), Third Performance Analysis such as Phase Back EMF, Inductance, Load torque using FEA (Finite Element Method). Finally, the reliability of proposed design methodology will be verified through the experiments of prototype sample.

• The KIPS Transactions:PartA
• /
• v.13A no.3 s.100
• /
• pp.191-198
• /
• 2006

Today's portable electric consumer devices, which are operated by battery, tend to integrate more multimedia processing capabilities. In the multimedia processing devices, multimedia system-on-chips can handle specific algorithms which need intensive processing capabilities and significant power consumption. As a result, the power-efficiency of multimedia processing devices becomes important increasingly. In this paper, we propose a reconfigurable data caching architecture, in which data allocation is constrained by software support, and evaluate its performance and power efficiency. Comparing with conventional cache architectures, power consumption can be reduced significantly, while miss rate of the proposed architecture is very similar to that of the conventional caches. The reduction of power consumption for the reconfigurable data cache architecture shows 33.2%, 53.3%, and 70.4%, when compared with direct-mapped, 2-way, and 4-way caches respectively.