• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 학술대회 논문집 전문대학교육위원
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• pp.141-146
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• 2006

According as level of industry develops day after day, electricity load system of industry requires high level control, effectiveness and high efficiency. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting and electric heating system. Therefore, in this paper proposed an inverter systems with constant current regulation and power factor correction (PFC) circuit for Lighting and Beaconing of Aerodromes. The effectiveness of the proposed system confirmed through experimental results of CCR.

• 조명전기설비학회논문지
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• 제27권10호
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• pp.93-100
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• 2013

Generally, the conventional battery charging system using an analog method has the large, heavy hardware and low efficiency. Also, it has the disadvantage that it is necessary to replace the control circuit on the basis of the characteristic curve of the specific battery cell. The proposed programmable digital LLC resonant charging system use high efficiency control system(CC-CV), and has characteristic a small hardware and advantage that a digital programming of the voltage, current, and battery capacity characteristics can be flexible. The system proposed the use of Half-bridge LLC resonant converter is possible to improve efficiency and reduce switching losses by using ZVS topology. Further, a constant voltage - constant current(CC-CV) control algorithm apply to the charger which using a buck converter. The performance of the proposed system is demonstrated through experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.3-5
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• 1994

It is shown that the power flow considering the voltage characteristic of the composite load has some difference comparing with conventional load flow in this paper. When the load flow is used in a study of the static voltage stability, it is necessary to consider the voltage characteristic of load, since the composite load of a typical power system bas constant power, constant current, and constant impedance characteristic. The load is modeled to a polynomial form in here, and used in solving the load flow problem. In this way, the effect which the voltage characteristic of the load has on several voltage collapse proximity indicator based on sensitivities is compared with the conventional load flow, or with another load model having a different voltage characteristic. In this paper, the voltage collapse proximity indicator using the sensitivity of real power for transmission loss is also proposed, and compared with other indicators.

• 대한수학회보
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• 제51권4호
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• pp.933-942
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• 2014

We give a representation of the component of solutions with characteristic multiplier 1 in a periodic linear inhomogeneous continuous system. It follows from this representation that asymptotic behaviors of the component of solutions to the system and to its associated homogeneous system are quite different, though they are similar in the case where the characteristic multiplier is not 1. Moreover, the representation is applicable to linear discrete systems with constant coefficients.

• 전기학회논문지
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• 제56권12호
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• pp.2150-2156
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• 2007

According as level of industry develops day after day, electricity load system of industry requires high level control, effectiveness and high efficiency. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting and electric heating system. But, problems that power factor deterioration and fast response of control, efficiency, harmonics and etc are still remain. Therefore, in this paper proposed an inverter systems with constant current regulation and power factor correction (PFC) circuit for lighting and beaconing of aerodromes. The effectiveness of the proposed system confirmed through experimental results of 10[kW] power supply system.

• 플랜트 저널
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• 제17권4호
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• pp.35-40
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• 2021

본 연구에서는 서인천복합 6호기 가스터빈 발전기계통에 대하여 기술특성시험을 실시하여 모델정수를 도출하고 검증하였다. 발전기 최대/최소 무효전력 한계시험 결과 최대 무효전력 한계는 80 MVar이고, 최소 무효전력 한계는 -30 MVar이다. 발전기는 GENROU 모델을 사용하였고, 계자시정수(T'do)는 4.077 s, 관성정수(H)는 5.461 P.U로 결정하였다. 여자시스템은 ESST4B 모델을 사용, 무부하 2% AVR 스텝시험을 모의하는 방식으로 모델정수를 도출하고 검증하였으며, PSS 모델링은 PSS2A 모델정수로 도출하였고, PSS Off/On일때 측정된 계측 데이터를 모의, 비교하여 검증하였다. 조속기-터빈는 GGOV1 모델을 사용하여 모델정수를 도출하고 검증하였다. PSS/E 시뮬레이션 프로그램을 통해 10% 조속기 스텝시험을 모의하여 결정된 조속기-터빈 모델정수의 수치 안정성을 확인하였다.

• 전기학회논문지P
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• 제56권4호
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• pp.173-178
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• 2007

As development of industry is accelerated, most electricity load system requires power supply that could be high precision and effective control. Among supply and control unit of suitable power supply in these load characteristic, inverter systems of constant current regulate is used widely control of lighting & beaconing of aerodromes and electric heating system. Therefore, in this paper proposed a inverter systems of constant current regulate that using improved measurement and switching techniques. Proposed measure techniques that used moving average method of instantaneous r.m.s. for measuring current sensing improved response and precision. Also, in this paper proposed improved high effectiveness switching techniques that get high efficiency of inverter by the double-carrier modulation. Results of an experiment proved effect of proposed system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1327-1331
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• 2004

In this paper constant power models for electric trains have been used to analyze the steady states of the AT feeding systems. There are some previous studies utilizing constant impedance models or constant current models. These mentioned models are easy to use, but even so they don't yield exact results because of the innate restraints of the models since linear models cannot represent the characteristic of constant power in inverter-driven trains. It is reasonable that the train be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. Nonlinear equations which reflect constant power model for train have been developed by considering mutual impedances between wires and AT's turn-ratio of 1:1, then these equations have been solved by N-R iterative method. The proposed method doesn't need any specific assumptions through either the process of developing equations or the process of acquiring solutions, so it can be said to be stricter than other conventional methods.

• 대한기계학회논문집B
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• 제22권6호
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• pp.803-812
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• 1998

In this study, testing equipment with which several kinds of valves can be tested was composed. Two kinds of tilting check valves and a swing check valve were tested to analyze their dynamic characteristics. The results of the experiment showed that the tilting check valves protected the pump but that the swing check valve could not protect the pump when the reverse flow rate was high. Also the dynamic equation of the tilting check valve was formulated and simulated using system characteristic constant t$_{c}$ and one method of predicting t$_{c}$ by comparing the results of the simulation with the results of the experiment was proposed.sed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.11-15
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• 2005

This paper presents a method to determine the characteristic polynomial of a closed loop all-pole system in order to obtain desired transient response in terms of the overshoot and speed (rising/settling time). The method adjusts the overshoot by doing some changes in the characteristic ratios of the Bessel-Thompson filter. The closed loop speediness is then tuned by suitable choice of the generalized time constant. Simulation results are presented to evaluate the achievements and make comparison with those of a similar method.