• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.36-38
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• 2001

A neutron controls a nuclear fission in the core of a reactor. Drive system for in-core neutron detector is an equipment that drives the detector and cable to survey neutron flux in the reactor. The drive system introduced by this paper was designed for mock-up system and fabricated to drive two drivers that having a different function. The system consists of a driver assembly, a power transmission part, and cable storage part. And there is a control panel that contains PLC and inverter. This paper is going to introduce the design and certify the operation status of completed system by control panal. And we conducted the test for torque measurement.

• 전력전자학회논문지
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• 제24권1호
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• pp.1-8
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• 2019

In this study, a maximum power point tracking (MPPT) algorithm based on the perturb and observe (P&O) method with variable step size is proposed to improve the dynamic response characteristic of MPPT, using the existing P&O method. The proposed algorithm, which we verified by simulation and experiment, can track the maximum power point (MPP) through duty control and consisted of three operation modes, namely, constant voltage mode, fast mode, and variable step mode. When the insolation is constant, the voltage variation of the operating point at the MPP is reduced through the step size reduction of the duty in the variable step mode. Consequently, the vibration of the operating point is reduced, and the power generation efficiency is increased. When the insolation changes, the duty and the photovoltaic (PV) voltage are kept constant through the constant voltage mode. The operating point then rapidly tracks the new MPP through the fast-mode operation at the end of the insolation change. When the MPP is reached, the operation is changed to the variable step mode to reduce the duty step size and track the MPP. The validity of the proposed algorithm is verified by simulation and experiment of a PV system composed of a PV panel and a boost converter.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.13-17
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• 2013

In lighting system where several large-area organic light-emitting diode (OLED) lighting panels are involved, panel aging may appear differently from each other, resulting in a falling-off in lighting quality. To achieve uniform light output across large-area OLED lighting panels, we have employed an optical feedback circuit. Light output from each OLED panel is monitored by the optical feedback circuit that consists of a photodiode, I-V converter, 10-bit analogdigital converter (ADC), and comparator. A photodiode generates current by detecting OLED light from one side of the glass substrate (i.e., edge emission). Namely, the target luminance from the emission area (bottom emission) of OLED panels is monitored by current generated from the photodiode mounted on a glass edge. To this end, we need to establish a mapping table between the ADC value and the luminance of bottom emission. The reference ADC value corresponds to the target luminance of OLED panels. If the ADC value is lower or higher than the reference one (i.e., when the luminance of OLED panel is lower or higher than its target luminance), a micro controller unit (MCU) adjusts the pulse width modulation (PWM) used for the control of the power supplied to OLED panels in such a way that the ADC value obtained from optical feedback is the same as the reference one. As such, the target luminance of each individual OLED panel is unchanged. With the optical feedback circuit included in the lighting system, we have observed only 2% difference in relative intensity of neighboring OLED panels.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.316-321
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system and tracking method. It is designed for power systems application and utilities. The proposed Maximum Power Point Tracking(MPPT) control has the advantage to provide a new simple way to approximate the optimal or rated voltage, the optimal or rated current and maximum power rating produced by a solar panel and the photovoltaic inverter. And this straightforward method will be named linear reoriented coordinates method(LRCM) with the advantage that Pmax and $V_{op}$ can be approximated using the satre variable as the dynamic model without using complicate approximations or Taylor series. Furthermore tracking method is improved over 50% photovoltaic efficiency. This paper is proposed MPPT using LRMC and tracking method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1215-1217
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system. It is designed for power systems application and utilities. The proposed Maximum Power Point Tracking(MPPT) control has the advantage to provide a new simple way to approximate the optimal or rated voltage, the optimal or rated current and maximum power rating produced by a solar panel and the photovoltaic inverter. And this straightforward method will be named linear reoriented coordinates method(LRCM) with the advantage that Pmax and $V_{op}$ can be approximated using the same variable as the dynamic model without using complicate approximations or Taylor series. This paper is proposed MPPT using LRMC method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.

• 조명전기설비학회논문지
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• 제21권6호
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• pp.55-64
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• 2007

본 논문은 부하직렬 고주파 공진 DC/DC 컨버터에 가변 가능한 공진커패시터를 병렬로 삽입한 LCC형 고주파 공진 DC/DC 컨버터의 특성과 설계 예를 나타내고 있으며, 또한 턴-오프시 스위칭 손실을 줄이기 위해 ZVS를 가지는 소프트 스위칭을 사용하였다. 제안 컨버터는 PFM(Pulse Frequency Modulation) 스위칭 패턴을 사용하여 동작되며, PFM 제어에 의해 제안 회로의 출력전압을 제어하였다. 병렬커패시터의 커패시턴스의 변화에 따라, DC/DC 컨버터의 분석은 일반적으로 무차원화 파라미터를 사용하여 나타내었고, 회로 동작 특성은 스위칭 주파수와 파라미터로 행하였다. 또한 본 논문은 특성평가에 의해 제안 DC/DC 컨버터의 동작 특성과 회로 설계 방법을 제시하였다. 더욱이 본 논문은 실험을 통해 이론 분석의 정당성을 입증하였다. 향후 제안한 DC/DC 컨버터는 반도체 및 FPD의 클린룸에 선형이동 시스템의 비접촉 전원장치에 적용 가능하다고 생각된다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 추계학술대회논문집
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• pp.47-55
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• 1996

This study developed a comprehensive and easily applicable nuclear reactor control system evaluation method using reactor operators behavioral and mental workload database. A proposed control panel design cycle consists of the 5 steps: (1) finding out inconvenient, erroneous, and mentally stressful factors for the proposed design through evaluative experiments, (2) drafting improved design alternatives considering detective factors found out in the step (1), (3) comparative experiements for the design alternatives, (4) selecting a best design alternative, (5) returning to the step (1) and repeating the design cycle. Reactor operators behavioral and mental workload database collected from evaluative experiments in the step (1) and comparative experiments in the step (3) of the design cycle have a key roll in finding out defective factors and yielding the criteria for selection of the proposed reactor control systems. The behavioral database was designed to include the major informations about reactor operators' control behaviors: beginning time of operations, involved displays, classification of observational behaviors, dehaviors, decisions, involved control devices, classification of control behaviors, communications, emotional status, opinions for man-machine interface, and system event log. The database for mental workload scored from various physiological variables-EEG, EOG, ECG, and respir- ation pattern-was developed to indicate the most stressful situation during reactor control operations and to give hints for defective design factors. An experimental test for the evaluation method applied to the Compact Nuclear Simulator (CNS) installed in Korea Atomic Energy Research Institute (KAERI) suggested that some defective design factors of analog indicators should be improved and that automatization of power control to a target level would give relaxation to the subject operators in stressful situation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.511-515
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• 1996

A remote controlled mobile robot system has been developed and tested to monitor the radiation area in the nuclear power plant. The mobile robot system operates according to car-driving-like commands and is capable of radiation measurement and visual inspection in unmanned situations under radiation. The robot system is equipped with a radiation sensor and two cameras with appropriate illumination set-ups. The camera with auto-focus function and 8-times zoom lens is mounted on the pan/tilt rotational base and the other is mounted on the front panel of the robot system. All commands regarding the motion of the mobile robot and various sensors are given through the monitoring system which is designed to provide an integrated man-machine interface.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.52-54
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• 2000

In PV power generation system study, huge system apparatuses are needed in order to verify the effect of system efficiency and stability considering the size of solar panels, the sort of converter types, and the load conditions and so on. And also, under the same weather and load conditions it is impossible to compare a certain MPPT control scheme to others. In this paper, in order to obtain effective solutions for the above mentioned topics, the solar cell array is simulated with it's VI characteristic equations, and the real field data of weather conditions is interfaced to EMTDC using Fortran program interface method. Consequently the simulation of PV power generation system using field data is realized in this paper, and acceptable results, which show close match between the real data of PV panel and the simulated data, were obtained.

• Journal of Power Electronics
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• 제15권4호
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• pp.920-928
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• 2015

Transformerless solar inverters have a higher efficiency than those with an isolation link. However, they suffer from a leakage current issue. This paper proposes a family of single phase six-switch transformerless inverter topologies with an ac bypass circuit to solve the leakage current problem. These circuits embed two unidirectional freewheeling current units into the midpoint of a full bridge inverter, to obtain a freewheeling current path, which separates the solar panel from the grid in the freewheeling state. The freewheeling current path contains significantly fewer devices and poor performance body diodes are not involved, leading to a higher efficiency. Meanwhile, it is not necessary to add a voltage balancing control method when compared with the half bridge inverter. Simulation and experiments are provided to validate the proposed topologies.