• 한국전기전자재료학회논문지
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• 제32권3호
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• pp.256-261
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• 2019

The use of military lithium batteries in this field accelerates the generation of internal pressure because the active materials, lithium and the electrolyte, react to form sulfur dioxide gas. This also reduces the amount of electrolyte. In this condition, batteries can 'vent' or 'explode' especially when completely discharged. Such venting and explosion can be regarded as a safety accident, as toxic gases and shrapnel are ejected from the batteries which can harm the user. A DTaQ was carried out in 2017 as a quality problem solution project to solve this safety issue. A protection circuit was thereby developed, which included a micro controller unit (MCU) which can stop battery usage when in an over-discharging state by sensing its low-voltage condition. In 2018, this concept was expanded to lithium batteries for the remote controlled ammunition system. This paper reports results of the improved performance.

• 한국통신학회논문지
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• 제38B권11호
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• pp.902-910
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• 2013

한국의 대표적 연구망인 KREONET은 사용자 가상회선 서비스를 위해 사전 예약 기반의 네트워크 서비스 에이전트인 DynamicKL 시스템을 개발하여 왔다. DynamicKL은 오픈 그리드 포럼 (OGF)에서 네트워크 자원 제어서비스를 위해 정의한 표준인 네트워크 서비스 인터페이스 (NSI) 및 그래픽 유저 인터페이스 (GUI)를 이용하여 예약, 할당, 해제, 종결, 조회 가상 회선 서비스를 제공한다. 또한 사용자에 의해 앞서 생성된 가상 회선과 예약들에게 가상회선 별로 보호 절체 관리 기능을 제공하기 위해 RICE 인터페이스를 갖는다. 본 논문은 DynamicKL 프레임워크 안에 구현된 가상회선 별 보호 절체 관리 기능을 가상 회선 서비스 관리 이슈 중 하나로 소개하고 이는 선진 연구망에서 개발한 다른 사전 예약 프레임워크 들과 비교하여 관리 및 안정성이 확보된 가상 회선 서비스를 제공하는데 기여한다. 관리자는 RICE 인터페이스를 사용하여 주회선 링크 장애시 백업 링크 안에 주 가상회선 들의 성공적인 보호 절체 유무 및 주회선 링크 복구 후 주회선 링크 내부에 주 가상회선 들의 성공적인 재생성 유무를 감지 할 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1637-1640
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• 2005

This paper presents a technique for electromagnetic field analysis on surge response due to Mid-span back-flashovers effects in lightning protection system of 500 kV EHV single circuit transmission tower by the neural networks method. These analyses are based on modeling lightning return stroke as well as on coupling the electromagnetic fields of the stroke channel to the line. The ground conductivity influences both the electric field as well as the coupling mechanism and hence the magnitude and wave shape of the induced voltage. The technique can be used to analyzed the corona voltage effect, the effective of stroke to the span tower, the surge impedance of transmission lines. The maximum voltage from flashovers effects in the lines. The model is compatible with general electromagnetic transients programs such as the ATP-EMTP. The simulation results show that this study analyses for time-domain with those produced by a cascade multi-section model, the surge impedance of a full-sized tower hit directly by a lightning stroke is discussed.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.489-492
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• 2000

This paper describes a new transient voltage suppressor(TVS) with a low insertion loss and a very wide frequency bandwidth to protect antenna circuit from transient voltages. Conventional protection devices have some problems such as low frequency bandwidth and high insertion loss. In order to improve these limitations, a coaxal type TVS, which consists of a gas tube is developed. The performance of the proposed transient voltage suppressor is tested by using a combination surge generator specified in IEC 61000-4-5 standard and by using a network analyzer of 40 MHz ∼ 5GHz bandwidth. From the experimental results, it is confirmed that the proposed TVS has an enough protection performance in low insertion loss and in wide frequency bandwidth

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.516-519
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• 2006

LCD TV의 대형화 추세에 따라 백라이트 구동용 인버터의 가격을 낮추고 휘도의 균일성을 보장하기 위해 다수개의 CCFL을 병렬로 구동하는 방식을 채택하고 있다. 그러나 다수개의 CCFL 중에 어느 하나가 먼저 점등되면, 등가 병렬저항이 점등된 램프 하나의 저항으로 나타나게 된다. 이 경우, 점등되지 못한 나머지 CCFL은 전등을 위한 충분한 전압을 받지 못하게 되어 전등이 되지 않은 상태로 머물러 있게 되고, 각 CCFL간의 과전류 편차로 인한 휘도 불균형이 문제점으로 나타나고 있다. 본 논문에서는 LCD 백라이트 구동용 인버터에서 발생하는 전압 전류의 출력 블균형에 대해서 연구하였으며, 이를 바탕으로 OVP(Over Voltage Protection), LCC(Limited Current Circuit), OLP(Open Lamp Protection)의 기존 Analog IC의 보호회로를 통합하여 하나의 MCU로 구성하였다.

• 한국정보통신학회논문지
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• 제26권10호
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• pp.1567-1570
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• 2022

This paper, we presents a RF protection technique of antenna switch by improving the power handling capability in worst case environment mode for mobile phone applications without critical payment of circuit performances such as insertion loss, isolation and ACBV (AC breakdown voltage). By applying a additional capacitive path located in front of the antenna in cell-phone, it performs the effective reduction of input power in high voltage standing wave ratio (VSWR) condition. Under the all-path off condition which causes a high VSWR, it achieved 37.7dBm power handling level as high as 5.7dB compared to that of conventional one at 2GHz. In addition, insertion loss and isolation performances were 0.31dB and 42.72dB at 2 GHz, respectively which were almost similar to that of the conventional circuit. The proposed antenna switch was fabricated in 130nm CMOS SOI technology.

• 한국초전도ㆍ저온공학회논문지
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• 제23권4호
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• pp.19-24
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• 2021

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protection problem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-to-turn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slow charging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply (PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. When a quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, the rotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causes the INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristic of HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quench protection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench, which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmed the protection characteristic of INS coils using a rotary HTS flux pump.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1250-1253
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• 2024

Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope ²³⁵U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.

• 대한전자공학회논문지
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• 제13권2호
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• pp.5-13
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• 1976

개소린 엔진 자동차의 연료절차, 공해감소, 보수경감을 목적으로 용량방전점화장치(CDI)를 해석적 및 실험적으로 설계하는 과정을 기술하였다. 특히 방전시스템에 대한 간단한 모델을 사용함으로써 점화코일의 입출력전압, 전류를 계산하였다. 그 결과 실험치와 비교하였으며 이로 부터 최적점화조건을 만족하기 위한 방전용량, SCR 및 다이오드의 정격과 DC-DC 콘버터의 소요출력전압을 결정하였다. 또 과도한 dv/dt 및 di/dt에 대한 SCR의 보호회로를 해석하고 그 결과를 관측된 결과를 관측된 결과와 비교하였는데 이로써 SCR선택과 보호회로 및 트리거 회로 설계가 용이하게 된다. 더우기 DC-DC콘버터의 거동에 대한 실험적 결과를 해석하므로써 콘버터 설계를 간이화하였다. 실용적인 CDI장치를 시작하였으며 이것은 실험실 및 노상 시험에서 만족할만한 성능을 나타냈다. 그 시험결과도 아울러 보고한다. An analytical and experimental design procedure is described for the Capacitor Discharge Ignition (CDI) System with a view to fuel saving ann reduction of gas exhaustion and maintenance need. Specifically, the input and output voltage and current of a given ignition coil were calculated by using a simplified circuit model for the discharging system. The results were compared with the experimental results, from which ratings of the charging capacitor, the SCR and the diodes and the required output valtage of the DC·DC converter were determined so as to satisfy the optimum ignition conditions. Protection circuits for excessive dv/dt and di/dt for the SCR were also analyzed and the results were compared with the observed results, which facilitate selection of the SCR and design of the protection circuit and the trigger circuit. Also, design of the DC·DC converter was simplified based on the analysis and experimental results of the behavior of the converter, An experimental, yet practical CDI system was built, which showed satisfactory performance in the laboratory and field tests. The results were also reported.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2927-2930
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• 2003

This paper has been studied the ballast for multiple lamps. Many fluorescent lamps are demanded in where industrial buildings and public buildings. Using the proposed ballast for multiple lamps, we can decrease the cost and the space for installing. Also in the paper, the protection circuit is introduced for over voltage and current. The general problem of the ballast for multiple lamps is to shut down the ballast circuit in the ease of one abnormal lamp. But the proposed method is not shut down all the circuit even if one lamp is in an abnormal condition.