• Journal of the Korean Society of Industry Convergence
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• v.25 no.3
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• pp.423-431
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• 2022

The UPS(Uninterruptible Power Supply) system operates in the battery charging mode when the grid is normal, and in the UPS mode, which is the battery discharge mode when a grid error occurs. Since the UPS must supply the same voltage as the grid to the load within 4 [ms] in case of a grid error, the switching time and power recovery time should be short when controlling the output voltage and current of the UPS, and the power failure detection time is also important. The power outage detection algorithm using DFT(Discrete Fourier Transform) proposed in this paper compares the grid voltage waveform with the voltage waveform including the 9th harmonic generated through DFT using Schmitt trigger to detect power outage faster than the existing power outage monitoring algorithm. There are advantages. Therefore, it is possible to supply instant and stable power when switching modes in the UPS system. The multi-power-applied UPS system proposed in this paper uses DFT, which is faster than the conventional blackout monitoring algorithm in detecting power failure, to provide stable power to the load in a shorter time than the existing power outage monitoring algorithm when a system error occurs. The detection method was applied. The changeover time of mode switching was set to less than 4 [ms], which is 1/4 of the system cycle, in accordance with KSC 4310 regulation, which was established by the Industrial Standards Council on the regulation of uninterruptible power supply. A 10 [kW] UPS system in which commercial voltage, vehicle generator, and auxiliary diesel generator can be connected to each of the proposed transfer devices was constructed and the feasibility was verified by conducting an experiment.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1778-1781
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• 1997

The coke oven plant on a steel works has not, in the past, been regarded as a prime user of modern instrument technology. The reason for this perception may be due to the fact that the basic design of the coke battery has been changed little over the years. The recording and analysis of oven pushing force on a routine basis is seen as a means of monitoring plant operation. A torque sensor is set up at the shaft of the rotor for measuring pushing force. Pushing force data which is communicated form torque sensor to staor by telemetry method are shown on MMI(Man-Machine Interface) screen and stored in the database automatically. Perhaps the most important feature is that is allows a problem oven to be identified at an early stage and for corrective action to be taken before it develops into a refusal to push. In this way the mechanical loads imposed on the battery structlure can be held to a necessary minimum, so helping to prolong its service life.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.410-413
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• 2004

In this paper, a simulator system for Fuel Cell Hybrid Electric Vehicles(FCHEV) is implemented using DSP boards with CAN bus. The subsystems of a FCHEV i.e., the fuel cell system, the battery system, the vehicle dynamics with the transmission mechanism are coded into 3 DSP boards. The power distribution control algorithm and battery SOC control are also coded into a DSP board. The real-time monitoring program is also developed to examine the control performance of power control and SOC control algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.423-426
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• 1996

The conditions to be satisfied with SOC(State-of-Charge) indicator installed on the electric vehicle were that it should be used under frequent loading conditions and that it should enable the monitor to adjust to the aging effect. But, the state-of-charge test requires a lengthy stabilization period after discharge cycles and the ampere-hour test requires the knowledge of the battery capacity in terms of amp-hours. However, a monitoring technique combining the state-of-charge test to enable the monitor to adjust to the aging effect with the ampere-hour test to use under frequent loading condition is studied and implemented on a microcontroller-based circuit in this paper. Specially, optical fiber is used to realize hydrometer which is immune to electromagnetic interference and toxic environment and makes it possible to be used in a wide temperature range.

• Journal of the Optical Society of Korea
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• v.20 no.3
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• pp.396-400
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• 2016

Laser speckle patterns were used to monitor variations of thermal voltages of a cathode during a battery discharge. Discharge voltages measured with an oscilloscope were utilized as a figure of merit of thermal voltages in Zn metal. Using an optical imaging system, speckle patterns were taken for zinc metal surface over a time period of 3 minutes. Pixel sum distribution functions (PSDFs) were extracted from speckle patterns. Accumulated pixel sums quantified from PSDFs over an optimized grayscale range strongly correlated with discharge voltages. This suggested that dark matter or particles may have the capability of both absorbing and radiating thermal energies simultaneously. The black body-like properties were able to be validated by identifying coincidences with distinct features of a black body spectrum. The pixels belonging to the grayscale range were confirmed to represent dark matter of a speckle pattern. It was clear that dark matter was part of surface plasmon carriers. The proposed sensing system can be applied to monitor thermal energy variations in any material.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2119-2126
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• 2016

In this paper, we developed a smart black box that can monitor and record the information of the sensor from subsystem in the smart grid system. The plant is the complex power system which is integrated by solar power system, grid-connected power systems, and BESS(battery energy storage system). The black box with the web-server application can connect and synchronize to an external monitoring system and a smart phone. We hope that this system is to contribute to improve operational efficiency, reliability, and stability for the smart grid power system.

• Journal of Aerospace System Engineering
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• v.8 no.4
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• pp.7-17
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• 2014

Objective of this paper is to introduce a new technology known as prognostics and health management (PHM) which enables a real-time life prediction for safety critical systems under extreme loading conditions. In the PHM, Bayesian framework is employed to account for uncertainties and probabilities arising in the overall process including condition monitoring, fault severity estimation and failure predictions. Three applications - aircraft fuselage crack, gearbox spall and battery capacity degradation are taken to illustrate the approach, in which the life is predicted and validated by end-of-life results. The PHM technology may allow new maintenance strategy that achieves higher degree of safety while reducing the cost in effective manner.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.576-577
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• 2012

본 연구에서는 자동차 납축전지를 위한 지능형 배터리 센서(Intelligent Battery Sensor; IBS) 모듈 기능검사장비를 개발한다. 이를 위해 IBS 모듈에 대한 기능 및 특성평가를 위한 기능 검사 시스템을 구축하고 LABVIEW를 이용한 기능검사 프로그램을 개발한다. IBS를 이용한 감시 제어 시스템은 배터리의 상태를 모니터링하여 최적의 조건을 유지하고 문제 발생 시에 미리 조치할 수 있다. 배터리의 상태 파라미터로는 전압, 전류, 온도를 사용한다. 감시 제어 시스템은 PC를 이용하여 환경을 구축하였으며 LabView를 이용한 GUI(Graphic User Interface)를 구축하여 배터리 데이터를 모니터링하고 저장, 관리가 편리한 장점을 가진다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1438-1440
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• 2005

A power control and distribution unit(PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU scheme for the small LEO Satellite applications. The main constitutes of the PCDU are the battery interface module, the auxiliary supply modules, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation. and instrument power distribution modules.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.28-33
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• 2016

Batteries are used for main power engine in the fields such as mobiles, electric vehicles and unmanned submarines, for starter and lamp driver in general automotive, for emergency electric source in ship. These days, lead-acid and the lithium ion batteries are increasingly used in the fields of the secondary battery, and the lead-acid battery has a low price and safety comparatively, The lithium ion battery has a high energy density, excellent output characteristics and long life, whereas it has the risk of explosion by reacting with moisture in the air. But Recently, due to the development of waterproof, fireproof, dustproof technology, lithium batteries are widely used, particularly, because their usages are getting wider enough to be used as a power source for hybrid ship and electric propulsion ship, it is necessary to manage more strictly. Hybrid ship has power supply units connected to the packets to produce more than 500kWh large power source, and therefore, A number of the communication modules and wires need to implement the wire inspection and monitor system(WIIMS) that allows monitoring server to transmit detecting voltage, current and temperature data, which is required for the management of the batteries. This paper implements a low price type wireless inspection and monitoring system(WILIMS) of the lithium ion battery for hybrid vessels using BLE wireless communication modules and power line modem( PLM), which have the advantages of low price, no electric lines compared to serial communication inspection systems(SCIS). There are state of charge(SOC), state of health(SOH) in inspection parts of batteries, and proposed system will be able to prevent safety accidents because it allows us to predict life time and make a preventive maintenance by checking them at regular intervals.