• 조명전기설비학회논문지
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• 제26권3호
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• pp.16-23
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• 2012

This paper relates to a study on the economic of electrical storage device for supplying power in sunless days, in the stand alone PV/Wind hybrid system, which it is applied to separate houses. In a photovoltaic/wind hybrid power system used in a separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. For example, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to supply power stably by only the battery based upon pre-estimated sunless days. Accordingly, in order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage.

• 전기학회논문지P
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• 제51권4호
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• pp.169-174
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• 2002

The developments of the solar and the wind power energy are neccessary since the future alternative energies that have no pollution and no limitation are restricted. Currently power generation system of existing problems, combined generation system of photovoltaic(400W) and wind power generation system(400W) was suggested. It combines wind power and solar energy to have the supporting effect from each other. However, weather condition, power compensation device that uses elastic energy of spiral spring to combined generation system was also added for the present study. In an experiment, when output of system gets lower than 12V(charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates in small scale generator.

• 한국초전도ㆍ저온공학회논문지
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• 제1권1호
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• pp.22-27
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• 1999

Recently, small-sized superconducting magnetic storage($\mu$SMES) coils become commercially as an energy storage device for a power conditioner. In design and fabrication of the $\mu$SMES coils, to determine optimum current capacity of the superconducting(SC) conductors is one of the important things. We thus investigated the effect of conductor's current capacity, current density, and stability on the coil's maximum stored energy density in consideration of AC losses and switching device's capacities in a power converter. The results show that the smaller current capacity of the SC conductors is preferred for the $\mu$SMES coils but can increase their induced voltage excessively.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권11호
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• pp.572-576
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• 2003

For quite a long time various researches and developments of superconducting magnetic energy storage(SMES) device have been done for enhancement of power qualify control of sensitive electric load. This paper describes the design. fabrication and experimental results for the 3MJ SMES magnet made by using the design code of a SMES device that we developed. A computer code was developed to find the parameters of the SMES magnet which has minimum amount of superconductor for the same stored energy, and the 3MJ SMES magnet was designed based upon that. And the 3MJ SMES magnet designed based upon those. In addition, 3MJ SMES magnet was made based on several research results which were ramp up to 1㎄ without quench.

• 인터넷정보학회논문지
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• 제16권5호
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• pp.29-38
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• 2015

에너지 저장장치(Energy Storage System)은 전력 수요가 적을 때 전력을 저장해 두었다가 수요가 발생하거나 비상시 저장된 전력을 사용함으로 전기 에너지를 저장하여 필요할 때 사용 가능함으로써 에너지 이용 효율 향상, 전력공급 시스템 안정화 및 신재생 에너지 활용도 향상 효과를 가지는 시스템이다. 최근 세계적으로 에너지의 효율적인 소비에 대한 관심이 증대되면서 전력의 안정적인 공급을 원하는 수요자와 전력 수요 평준화를 원하는 공급자의 요구를 충족시켜줄 수 있는 에너지 저장장치의 필요성이 증대되고 있다. 현재 에너지 저장장치를 구성하는 Power Conditioning System(PCS), Battery Management System(BMS), 배터리 셀은 제조사별로 상이한 규격을 가진다. 이로 인해 각 핵심 부품 간 인터페이스가 규격화되어 있지 않아, 에너지 저장장치의 구성 및 운영에 난점으로 작용하고 있다. 본 논문에서는 제조사별로 상이한 특징을 가지는 부품들의 설정과 효율적 운영에 필요한 정보를 수용하여 에너지 저장장치를 구성할 수 있는 XML 기반의 에너지 시스템 전용 프로파일 시스템의 설계와 분석방안을 제안한다. 제조사별 PCS, BMS, 배터리 셀과 그 외의 주변 기기들의 설정 정보 및 운영 정보를 분석하여 프로파일 규격을 정의하고, 에너지 저장장치에 적용할 수 있는 프로파일 어댑터 소프트웨어를 설계 및 구현한다. 프로파일 어댑터를 통해 생성된 프로파일은 설정 프로파일과 운영 프로파일로 구성되며, 추후 확장성을 고려하여 표준 XML의 규격을 따른다. 구현된 프로파일 시스템의 검증은 에너지 저장장치 시스템에 적용되어 기본적인 충 방전 동작을 통해 정상 동작 결과를 제안한다.

• 전기학회논문지
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• 제60권4호
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.

• Journal of Power Electronics
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• 제15권4호
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• pp.1026-1034
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• 2015

In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.498-500
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• 2012

According to the climatic characteristics of the wind power output is difficult to predict and a severe strain due to a change in output has been very influential in the grid. Jeju Hangwon wind farm, many of the wind generator is installed in a wide area because it is not have this device that artificially Smoothing is needed. In addition, By the requirements of the power company active power supply / control and improve power system reliability and energy storage during the peak demand for electricity using the energy stored in the power supply is needed. In this paper, Unit 12 in Jeju Hangwon demonstrated 0.5MW PCS and energy storage system associated with the wind through the stabilization of output and the leveling of output and test results will be introduced.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.326-332
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• 1999

The flywheel generator in use as a power source for experimental device can be large enough to generate the electric power to make it suitable for application in wide rage of industries. The proposed system pruduces the good performance for power control. In this paper, the validity of the flywheel for power storage is described and the new control method which applies the space vector control scheme are proposed. This system is superior to conventional power compensator in the aspect of stability improvement and it is possible to make the converter capacity small. Continuous operation by flywheel can be realized even during power network faults such as 1-line ground.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.442-448
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• 2022

Intermediate-level radioactive waste (ILW) is not subject to legal approval for cave disposal in Korea. To solve this problem, a spent resin treatment device that separates ¹⁴C-containing resin from zeolite/activated carbon and desorbs ¹⁴C through a microwave device has been developed. In this study, we evaluated the radiological safety of the operators performing repair work in the event of a failure in such a device treating 1 ton of spent resin mixture per day. Based on the safety evaluation results, it is possible to formulate a design plan that can ensure the safety of workers while developing a commercialized device. When each component of the resin treatment device can be repaired from the outside, the maximum and minimum allowable repair times are calculated as 263.2 h and 27.7 h for the ¹⁴C-detached resin storage tank and zeolite/activated carbon storage tank, respectively. For at least 6 h per quarter, the worker's annual dose limit remains within 50 mSv/year; further, over 5 years, it remained within 100 mSv. At least 6 h of repair time per quarter is considered, under conservative conditions, to verify the radiological safety of the worker during repair work within that time.