• Fire Science and Engineering
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• v.23 no.2
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• pp.55-61
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• 2009

This study has been carried on the transient phenomenon protection system to become fire alarm system control unit of high reliance which can be protected from transient phenomena for surge or transient overvoltage, and constructed engineering base that can develop transient phenomenon protection system by proving performance of protection system in a experimental. This study developed 1 step and 2 step protection system that can be protected from transient phenomenon with process thesis and theory for development of transient phenomenon protection system. It established engineering data construction and a source technology that can develop transient phenomenon protection system as gets satisfied result and test with all performance condition that present in fire protection law and connection regulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.5
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• pp.62-70
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• 2002

Methodology of predicting steady performance of gas turbine engine from transient test data was explored to develop an economic performance test technique. Discrepancy of transient performance from steady performance was categorized as dynamic, thermal and aerodynamic transient effects. Each effect was mathematically modeled and quantified to provide correction factors for calculating steady performance. Engine performance tests were conducted at Altitude Engine Test Facility of KARI. The influence of engine inlet/outlet condition change on engine performance was corrected firstly, and then steady performance was predicted from the correction factors. The result was compared with steady performance test data. This correction method showed an acceptable level of precision, 3.68% difference of fuel flow.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.1-10
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• 2003

Methodology of predicting steady performance of gas turbine engine from transient test data was explored to develop an economic performance test technique. Discrepancy of transient performance from steady performance was categorized as dynamic, thermal and aerodynamic transient effects. Each effect was mathematically modeled and quantified to provide correction factors for calculating steady performance. The influence of engine inlet/outlet condition change on engine performance was corrected firstly, and then steady performance was predicted from the correction factors. The result was compared with steady performance test data. This correction method showed an acceptable level of precision, 3.68% difference of fuel flow.

• 연구논문집
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• s.30
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• pp.5-13
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• 2000

The computation scheme of simulating gas turbine transient behavior was developed. The basic principles of this scheme and main input data required are described. Calculation results are presented in terms of whole operating regime of the cycle. The influence of main initial parameters such as starting engine power, moment of inertia of the rotor, fuel supplying schedule etc. on performance characteristics of has turbine during transient operation is studied In addition, bleeding air influence on transient behavior was also considered For validation of the developed code, comparison of present calculation with that of measurement data of the experimental data for the range of operating period studied.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1727-1732
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• 2010

The Current transformer is classified measuring CT and protective CT for their purpose. The measuring CT is required to retain a specified accuracy over the normal range of load currents, but the protective CT must be capable of providing an adequate output over wide range of fault condition. Therefore, the protective CT must determine the transient performance during fault condition. This paper measured peak instantaneous error of the TPY class CT to determine the transient performance directly and indirectly and studied the test results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.81-90
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• 1999

The performance evaluation technique of a heat exchanger is described by using a transient response analysis for the determination of an average heat transfer coefficient. The model using a finite difference method can accommodate arbitrary inlet fluid temperature as well as longitudinal conduction. Temperature histories are obtained from the experiments at the inlet and outlet of test core. Heat transfer coefficient and friction factor of the plate array are obtained in short times using the data reduction program of transient response analysis in the single-blow method. The results agree very well with theoretical results. It is shown that the rms deviations are very small and the performance evaluation technique gives rapid and accurate results.

• Proceedings of the KIEE Conference
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• summer
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• pp.839-841
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• 2004

IEC 60044-6 (Requirements for protective current transformers for transient performance) was established to Korea Standard (KS C IEC 60044-6 ; Instrument transformers Part 6 ; Requirements for protective current transformers for transient performance) in December 11, 2003. In this paper, requirements, test items and test methods protective current transformers for transient performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.6
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• pp.28-34
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• 2011

This paper describes the development of the transient analysis model of 345[kV] 100[MVA] STATCOM and the result of the performance analysis. The Korea power utility company, KEPCO began a commercial operation of a 100[MVA] STATCOM(Static synchronous COMpensator) at 345[kV] Migeum substation in Seoul. In order to operate a new control device like STATCOM to the power system, suitable transient model is needed. Therfore, Korea Electric Power Coporation(KEPCO) developed a transient analysis models using EMTDC/PSCAD. The development of this transient analysis model is based on the actual STATCOM S/W algorithm and H/W specification that was provided by its manufacture. Through this model, the transient/dynamic performance of STATCOM at Migeum substation can be analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.513-520
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• 2004

A steady-state/transient performance simulation model was newly developed for the propulsion system of the CRW (Canard Rotor Wing) type UAV (Unmanned Aerial Vehicle) during flight mode transition. The CRW type UAV has a new concept RPV (Remotely Piloted Vehicle) which can fly at two flight modes such as the take-off/landing and low speed forward flight mode using the rotary wing driven by engine bypass exhaust gas and the high speed forward flight mode using the stopped wing and main engine thrust. The propulsion system of the CRW type UAV consists of the main engine system and the duct system. The flight vehicle may generally select a proper type and specific engine with acceptable thrust level to meet the flight mission in the propulsion system design phase. In this study, a turbojet engine with one spool was selected by decision of the vehicle system designer, and the duct system is composed of main duct, rotor duct, master valve, rotor tip-jet nozzles, and variable area main nozzle. In order to establish the safe flight mode transition region of the propulsion system, steady-state and transient performance simulation should be needed. Using this simulation model, the optimal fuel flow schedules were obtained to keep the proper surge margin and the turbine inlet temperature limitation through steady-state and transient performance estimation. Furthermore, these analysis results will be used to the control optimization of the propulsion system, later. In the transient performance model, ICV (Inter-Component Volume) model was used. The performance analysis using the developed models was performed at various flight conditions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the turbine inlet temperature overshoot limitation as well as the compressor surge margin. Because the engine performance simulation results without the duct system were well agreed with the engine manufacturer's data and the analysis results using a commercial program, it was confirmed that the validity of the proposed performance model was verified. However, the propulsion system performance model including the duct system will be compared with experimental measuring data, later.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.285-289
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• 2013

In switching from the track-seeking or track-jumping control mode to track-following control mode in hard disk drives or optical disk drives, initial values of the feedback controller are tuned to improve the transient response. In general, all the initial values of the controller have been compensated for this purpose. In this paper, by partially compensating initial values of digital controllers, we achieve a good performance of the transient response. In the proposed method for IVC (Intial Value Compensation), LMIs (Linear Matrix Inequalities) are used, which includes conditions for improving the performance of the transient response such as reducing a tracking error and control efforts. We obtain optimal initial values of the controller by solving an optimization problem with constraints represented by only one LMI. Although initial values of the controller are partially compensated, we can show that not only a sufficient performance of the transient response is obtained but also control efforts are diminished. The feasibility of the method is verified by simulation studies.