• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1933-1935
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• 1997

The availability of high power IGBT has led to development of controllable reactive power and harmonics compensation source for use in power transmission system. The paper describes the fundmental operating principles and several application examples. The control technique of reactive power and harmonics compensation for Distribution STATCON is presented, and the computer simulation results are shown to show the effectiveness of tile proposed control technique.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.880-883
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• 1998

In this paper, sensitivity based approach to estimate BITC(bilateral interchange transfer capacity) considering the real power flow control function of FACTS device is presented. The real power flow setting of the FACTS device is adjusted so that it transfer the power flow from the first violation point of transmission capacity to other transmission lines in the power system, thus allowing more power to be transferred from the specified generator bus to the specified load bus. The transfer between the two bus locations is increased from this new operating condition until a violation of transmission capacity limits occurs or until the setting of the FACTS device can no longer be adjusted. The proposed algorithm is illustrated using examples of small and real life power system.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.101-102
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• 2008

우리나라 계통(KEPCO System)은 수도권지역의 부하집중과 장거리 송전, 발전단가 등의 경제적인 문제로 인해 계통의 안정도 문제가 대두되고 있다. 이에 계통의 안정도 향상을 위해 양주, 미금, 동서울 세 지역에 FACTS 기기를 투입하게 되었다. FACTS기기는 전력전송의 향상을 가져오고 계통에 연결된 여러 전력기기들의 활용을 극대화시킬 수 있는 장점이 있다. 이러한 FACTS 기기의 투입이 우리나라 계통 안정도의 큰 향상을 위하여 효율적인 운용방안 필요하다. 이에 본 논문에서는 FACTS 기기의 협조 운전 전략을 위한 계통 검토와 FACTS 운전 전략을 확립하고자 한다.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.835-837
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• 1997

This paper presents a control system design for the STATCON of FACTS devices by LQR, LQG control scheme to enhance small-signal stability in the power system, the feature of this FACTS controller is coordinated with generator exciter controller(AVR, PSS) to improve the total power system stability and performance.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.211-218
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• 2002

We propose a intelligent controller for FACTS device to stabilize a power system. In order to identify the nonlinear characteristics of the power system and to estimate a control signal, an artificial neural network is utilized. Parameter and location of Unified Power Flow Controller(UPFC) on power system operating conditions are discussed. A UPFC is composed of an excitation transformer, a boosting, two three-phase GTO based voltage source converters, and a dc link capacitor. The proposed controller is applied to UPFC to verified the effectiveness of the proposed control system. The results show that the proposed nonlinear FACTS controller is able to enhance the transient stability of a three machine and nine bus system.

• Transactions on Electrical and Electronic Materials
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• v.18 no.5
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• pp.303-309
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• 2017

The flexible AC transmission system (FACTS) provides a new advanced technology solution to improve the flexibility, controllability, and stability of a power system. The unified power flow controller (UPFC) is outstanding for regulating power flow in the FACTS; it can control the real power, reactive power, and node voltage of distribution networks. This paper investigates the performance of the UPFC for power flow control with a series of step changes in rapid succession in a power system steady state and the response of the UPFC to distribution network faults and islanding mode. Simulation was carried out using the MATLAB's simulink sim power systems toolbox. The results, which were carried out on a 5-bus test system and a 4-bus multi-machine electric power system, show clearly the effectiveness and viability of UPFC in rapid response and independent control of the real and reactive power flows and oscillation damping [6].

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.142-144
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• 2000

This paper presents an auxiliary TCSC controller designed for damping SSR. Damping controller for SSR is designed in frequency domain for suppressing resonance. The SSR phenomenon and the performance of damping controller simulated by using PSCAD/EMTDC. In this simulation. the power system model for SSR is IEEE benchmark Model and TCSC is simplified to controllable impedance model.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.16-18
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• 2004

The flexible AC transmissions system (FACTS) is the underpinning concept upon which are based promising means to avoid effectively power flow bottlenecks and ways to extend the loadability of existing power transmission networks. This paper proposes a method by which the optimal locations of the FACTS to be installed in power system under cost function. The optimal solution of this type of problem requires large scale nonlinear optimization techniques. We used Lagrange multipliers to solve a nonlinear equation with equality and ineaquality constraints. Case studies on the standard IEEE 14 bus system show that the method can be implemented successfully and that it is effective for determining the optimal location of the FACTS.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1659-1663
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• 1991

A new control design methodology is presented here which is based on a nonlinear time-series reference model. It is indicated by highly nonlinear simulations that such designs successfully stabilize troublesome aircraft maneuvers undergoing large changes in angle of attack as well as large electric power transients due to line faults. In both applications, the nonlinear controller was significantly better than the corresponding linear adaptive controller. For the electric power network, a flexible a.c. transmission system (FACTS) with series capacitor power feedback control is studied. A bilinear auto-regressive moving average (BARMA) reference model is identified from system data and the feedback control manipulated according to a desired reference state. The control is optimized according to a predictive one-step quadratic performance index (J). A similar algorithm is derived for control of rapid changes in aircraft angle of attack over a normally unstable flight regime. In the latter case, however, a generalization of a bilinear time-series model reference includes quadratic and cubic terms in angle of attack. These applications are typical of the numerous plants for which nonlinear adaptive control has the potential to provide significant performance improvements. For aircraft control, significant maneuverability gains can provide safer transportation under large windshear disturbances as well as tactical advantages. For FACTS, there is the potential for significant increase in admissible electric power transmission over available transmission lines along with energy conservation. Electric power systems are inherently nonlinear for significant transient variations from synchronism such as may result for large fault disturbances. In such cases, traditional linear controllers may not stabilize the swing (in rotor angle) without inefficient energy wasting strategies to shed loads, etc. Fortunately, the advent of power electronics (e.g., high-speed thyristors) admits the possibility of adaptive control by means of FACTS. Line admittance manipulation seems to be an effective means to achieve stabilization and high efficiency for such FACTS. This results in parametric (or multiplicative) control of a highly nonlinear plant.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.229-231
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• 2000

Precision control technologies are required for Lithography devices. The Linear BLDC Motor is used for operations of the stage. The stage is installed in Lithography devices. The stage is basically controlled though three directions (x, y, z axes). This paper presents precision control technologies of the Linear BLDC Motor (only one axes) by using computer simulations. We will plan that real systems is made and tested.