• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.19-25
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• 2012

About supply and demand to see that you need to match, the limitations of wind power capacity is low demand and the commitment of the general generator will exist between the minimum generation. if the turbine's output can be controlled, The limitation of wind power capacity will be adopted based on instant power generation. Namely, The minimum limits of wind power generation based load operation by calculating the amount that is higher than if the output should be restricted to highest operation. in this paper, we committed to the demand for low enough that the combination of the general generator of wind power capacity to accommodate the operation of determining whether the limit is intended to. For this, power system analysis program PSS/E was used, Jeju system by implementing the model simulations were performed.

• 전기전자학회논문지
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• 제22권3호
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• pp.754-758
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• 2018

전력계통에서 해석 하는 방법종류로 정적해석과 동적해석 그리고 온라인 해석과 오프라인 해석으로 나뉜다. 기존의 계통 해석하는 방법으로는 오프라인 정적해석을 이용하며 PSS/E에서도 정적해석을 주로 사용한다. 하지만 우리가 사용하고 있는 실제 계통에서는 실시간으로 값이 변한다. 정확한 해석을 하기 위해 실시간으로 해석이 가능한 온라인 해석과 동적해석이 요구되며 이에 따라 EMS(Energy Management System)에 대한 중요도가 높아지고 있다. 본 논문에서는 다양한 EMS시스템 중에서도 실시간으로 취득 점으로부터 데이터를 받아와 해석 할 수 있는 정적 온라인 해석인 상태추정을 다룰 것이다. 오늘날 DC부하, DC배전망, 신재생에너지 등 다양한 분야에서 DC계통이 확산되고 있다. 이처럼 DC계통에 많은 관심과 이목이 집중되고 있다. 본 논문에서는 DC계통에 접목시킬 수 있는 상태추정에 대한 해석과 사례연구를 통한 사용가능성에 대해 연구하였다.

• 전력전자학회논문지
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• 제5권6호
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• pp.584-591
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• 2000

컴퓨터와 같은 민감한 부하를 전압강하나 정전과 같은 전원 장애로부터 보호하기 위하여 전력보상장치가 설­치되어 왔다. 전력보상장치의 경우 계통과의 연계를 위해 대부분 정지형 스위치를 이용하고 있으며, 이러한 정지형 스위치의 전환동작은 매우 중요한 부분을 차지하고 있다. 그간 전략보상장치의 구조나 제어에 관한 연구는 활발하게 진행되어 왔으나 전력보상장치의 운전을 시작하기 위한 전원 장애의 감지에 판한 연구는 매우 드문게 현실이다. 따라서 본 논문에서는 정지형 스위치 절환동작을 위해 CBEMNITIC 커브를 이용하여 컴퓨터 응용부하판 위한 새보운 전원 장애 검출 암고리즘을 제안한다. 제안된 검출 알고리즘은 동기 좌표계에서 직류 값으으 변환된 삼상 순시 전압값을 동작 기준값과 비교하는 방법을 사용하여 빠른 검출 시간을 가지도록 하였다. 그리고, 간단한 1차 디지텔 필터를 삽입하여 잡음에 강인하도록 선거하였다. 이러한 필터에 의해 나타나는 위상지연 및 이득감소를 각각 전달함수를 이용한 수식적인 해석과 오차의 정규화를 통해 보상하였다. 마지막으로 ACSL를 이용한 시뮬레이션파 실험을 통해 제안된 알고리즘의 타당성을 입증하였다.

• 유공압시스템학회논문집
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• 제8권4호
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• pp.9-16
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• 2011

Because of the increasing demand on the high precision and high response of a machinery, proportional control valves are widely adopted at various application fields. This paper studies on the static and dynamic characteristics of a pilot proportional pressure control valve. An experimental apparatus including hydraulic pump, variable speed inverter, pressure and flow sensors and data aquisition system was set up. And various experiments such as P-Q-V curves, step responses due to input voltage and flow rate, hysteresis, frequency response of the proportional valve was carried out and the results are discussed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.204-210
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• 1997

The paper deals with the design and evaluation of a new static-exciter for generator excitation systems to improve the steady-state and transient stabilities. It increases or maintains the generator field current by boosting the field voltage in the case of an input AC line voltage drop during and immediately after a fault. The validity of the proposed excitation system is verified with computer simulation. The simulation results of the stability analysis on the generator with the proposed exciter is better than that of a conventional static exciter and a conventional AC exciter. Also, this proposed exciter can be simply implemented and controlled by modern power electronics technology.

• Journal of Electrical Engineering and Technology
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• 제4권2호
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• pp.175-184
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• 2009

In this paper, a method for optimal measurement placement in the problem of static harmonic state estimation in power systems is proposed. At first, for achieving to a suitable method by considering the precision factor of the estimation, a procedure based on Genetic Algorithm (GA) for optimal placement is suggested. Optimal placement by regarding the precision factor has an evident solution, and the proposed method is successful in achieving the mentioned solution. But, the previous applied method, which is called the Sequential Elimination (SE) algorithm, can not achieve to the evident solution of the mentioned problem. Finally, considering both precision and economic factors together in solving the optimal placement problem, a practical method based on GA is proposed. The simulation results are shown an improvement in the precision of the estimation by using the proposed method.

• 한국철도학회논문집
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• 제3권3호
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• pp.170-176
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• 2000

Nowadays, the vehicle structure weight of urban transit system has been reduced in order to save energy and materials. However, this light weighted vehicle structure is very important to verify the fatigue strength at the development stage. Bogie system consists of bogie frame, suspensions, wheel-sets, braking system and transmission system. Among these components, the bogie frame is most significant component subjected to the whole vehicle and passenger loads. In this study, the bogie frame for the standard EMU power car is evaluated to the static and fatigue strength. And, the evaluation method is used the JIS E4207 specification throughout the FEM analysis and static load test. The static and fatigue test results for the standard EMU bogie frame of power car has been appeared very safety and stable for the design load conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2025-2026
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• 2008

This study aims to analyze the features of malfunction of an SFC that helps maintain the frequency of static rotation during the operation of a gas turbine in power plants where power generators and controllers have such a complicated structure as a nerve system, by using electric interference with peripheral devices and maintaining acquired data efficiently. Also, in order to track the possibility of malfunction by various surges and noises which may occur in the process of inserting an SFC during the operation of a gas turbine and to prepare protective measures for the possibility, the study intends to offer data for developing a surge protector suited to the features of a section that is supposed to incur the possibility of malfunction.

• 대한기계학회논문집B
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• 제27권7호
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• pp.984-994
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• 2003

The suitability of high-order accurate, centered and upwind-biased compact difference schemes for large eddy simulation is evaluated by a spectral, static error analysis. To investigate the effect of numerical dissipation on LES solutions, power spectra of discretization errors are evaluated for isotropic turbulence models in both continuous and discrete wavevector spaces. Contrary to the common belief, the aliasing errors from upwind-biased schemes are larger than those from comparable non-dissipative schemes. However, this result is the direct consequence of the definition of the power spectral density of the aliasing error, which poses the limitation of the static error analysis for upwind schemes.

• Journal of Power Electronics
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• 제16권3호
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• pp.1004-1011
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• 2016

The inaccurate model parameters in the predictive current control of surface-mounted permanent magnet synchronous motor (SMPMSM) affect the current dynamic response and steady-state error. This paper presents a model parameter correction algorithm based on the relationship between the errors of model parameters and the static errors of dq-axis current. In this correction algorithm, the errors of inductance and flux are corrected in two steps. Resistance is ignored. First, the proportional relations between inductance and d-axis static current errors are utilized to correct the error of model inductance. Second, the flux is corrected by utilizing the proportional relations between flux and q-axis static current errors under the condition that inductance is corrected. An experimental study with a 100 W SMPMSM is performed to validate the proposed algorithm.