• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.3
• /
• pp.276-284
• /
• 2009

In this paper, we develop the image transfer remote maintenance monitoring system for hand held device which can compensate defects of human mistake. The human mistakes always happen when the worker communicate information each other to check and maintenance the equipment of the power plant under bad circumstance such as small place and long distance in power plant. A worker couldn't converse with other when in noisy place like Power plant. So, we make some hand device for handy size and able to converse in noisy place. The developed system can have improvement of productivity through increasing plant operation time. And developed system is composed of advanced H/W(hard ware) system and S/W(soft ware)system. The H/W system consist of media server unit, communication equipment with hand held device, portable camera, mike and head set. The advanced s/w system consist of data base system, client pc(personal computer) real time monitoring system which has server GUI(graphic user interface) program, wireless monitoring program and wire ethernet communication program. The client GUI program is composed of total solution program as pc camera program, and phonetic conversation program etc.. We analyzed the required items and investigated applicable part in the image transfer remote maintenance monitoring system with hand held device. Also we investigated linkage of communication protocol for developed prototype, developed software tool of two-way communication and realtime recording skill of voice with image. We confirmed the efficiency by the field test in preventive maintenance of plant power.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.163-165
• /
• 2007

Generally, the power management system of fuel cell hybrid vehicle (FCHV) requires a unidirectional DC/DC converter for the fuel cell (FC) and a bidirectional DC/DC converter for the battery. To manage the various power flows between these modules with a simple way, a new band-gap reference voltage (BGRV) control strategy is proposed. The proposed method easily controls this variable power flow by setting the reference voltages of each converter to slightly different values, and it can be simply implemented by commercial controllers as well. The operational principle of proposed method is presented and verified experimentally by the 400W prototype.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.6
• /
• pp.416-426
• /
• 2008

The boiler tube failure often experienced in the superheater of a utility boiler can seriously affect the economic and safe operation of the power plant. It has been known that this failure is mainly caused by the thermal load deviation in the superheater tube system, and deeply intensified by the non-uniform distribution of steam flow rates. The nonuniform steam flow is distinctively prominent at low power load rather than at full power load. In this paper, we analyze the steam flow distribution in the superheater tube system by using one dimensional flow network model. At 30% power load, the deviation of steam flow rate is predicted to be within 0.8% of the averaged flow rate. This deviation can be reduced to 0.1% and 0.07% by assuming two cases, that is, the removal of 13th tube at each tube rows and the installation of intermediate header, respectively. The assumed two cases would be effective for the uniform steam flow distribution across 85 superheater tube rows.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.4
• /
• pp.94-101
• /
• 2015

Each of power systems of solar cell and fuel cell were configured and validated for long endurance UAV, as the preliminary research for the integration of power systems. Solar power system consisted of solar modules fabricated by solar cells of Sunpower's C60, commercial solar MPPT controller and Li-po battery, and then was validated. The re-start characteristics of hydrogen production from $NaBH_4$ hydrolysis was validated for operating the commercial fuel cell. The average voltage drop of Li-po battery in solar power system was -2.9 V/hour. The performance of re-start characteristics of $NaBH_4$ hydrolysis was stable in sequence mode of mission profile. Each of single systems were satisfied for the proposed mission profile.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.8
• /
• pp.1123-1128
• /
• 2008

Marine facilities like buoy, lighthouse are operated with stand alone power supply system. This power system can consist of a stand-alone type power system such as PV(Photovoltaic) system, wave system or hybrid system which is not cooperated with a commercial power system. Generally, PV power system for marine facilities can not supply a sufficient power to buoy, because it is so influenced from weather condition. For solving this problem the hybrid power system with PV and wave is studied on a various area, that is why a hybrid power system is requires to overcome these problems. This paper will describe a generation characteristic of WEC(Wave Energy Converter) for buoy, and an AFS(Anti-Fouling System) influence on WEC.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1771-1774
• /
• 2005

Recently, RFID has become popular in the field of remote sensing applications. Location awareness is one of the most important keys to deploying RFID for advanced object tracking. Generally, multiple reference RF stations or additional sensors are used for the location sensing with RFID, but, particularly in indoor environments, spatial layout and cost problems limit the applicability of those approaches. In this paper, we propose a novel method for location sensing with active RFID systems not requiring the need for reference stations or additional sensors. The system triangulates the position of RF signal source using the signal pattern of the loop antenna connected to the power detector. The power detector consists of a signal strength detector and a signal analysis unit. The signal analysis unit indicates the signal strength and serial number using the signal from the strength detector, and provides the direction of the signal to the application target. We designed three different signal analysis units depending on the threshold type. The developed system can sense the direction to the transponder located over 10 m away within the maximum error of $5^{\circ}$. It falls within a reasonable range in our normal office environment.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.27-36
• /
• 2014

This paper presents an adaptive wide-area damping controller (WADC) based on generalized predictive control (GPC) and model identification for damping the inter-area low frequency oscillations in large-scale inter-connected power system. A recursive least-squares algorithm (RLSA) with a varying forgetting factor is applied to identify online the reduced-order linearlized model which contains dominant inter-area low frequency oscillations. Based on this linearlized model, the generalized predictive control scheme considering control output constraints is employed to obtain the optimal control signal in each sampling interval. Case studies are undertaken on a two-area four-machine power system and the New England 10-machine 39-bus power system, respectively. Simulation results show that the proposed adaptive WADC not only can damp the inter-area oscillations effectively under a wide range of operation conditions and different disturbances, but also has better robustness against to the time delay existing in the remote signals. The comparison studies with the conventional lead-lag WADC are also provided.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.1945-1947
• /
• 1997

In this paper, a characteristics analysis of the grid-connected photovoltaic power generation system which uses the simulation method of PV array is reported. The control method of DC/AC power conversion were suggested to establish the basic application technology of photovoltaic systems. The results of the demonstration test of a 3kW grid-connected PV system show that the system utilization rate is 17.6% and the system efficiency is 8.9%.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.10a
• /
• pp.106.2-106
• /
• 1999

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05b
• /
• pp.631-636
• /
• 1996

This paper presents a Reliability Centered Maintenance (RCM) framework for implementation on safety system of nuclear power plant (NPP). RCM is a systematic methodology to optimize the surveillance and maintenance tasks for critical components which provides efficiently and effectively reliability of system and safety of plant. Maintenance of the safety systems is essential for its safe and reliable operation. Reliability Centered Maintenance at NPP is the program which assure that plant system remains within original design criteria and that is not adversely affected during the plant life time. Aim of this paper is to provide the RCM framework to implement it on safety systems. RCM framework is described in four major steps.