• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.187-189
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• 2001

In this paper, we have simulated the transient stability of power system with dynamic loads. Dynamic load characteristics have an important influence on power system stability. In study of power system stability, motors form a major portion of the system loads. Induction motors and synchronous motors in particular form the workhorse of the electric power industry. Therefore modelling of motors is important in system stability. We investigate the effect of motors loads of Kwang Yang network with three phase fault.

• 한국산학기술학회논문지
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• 제13권9호
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• pp.4146-4151
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• 2012

본 논문에서는 동적 부하를 고려한 전력계통의 과도 안정도 해석을 모의하고자 한다. 모터는 계통 부하의 주요부분을 차지하고 있으며 이들의 동적 부하 특성은 전력계통의 안정도 해석에 있어서 매우 중요한 요소이다. 전력계통의 안정도해석에서 개별 부하의 특성을 모두 반영할 수 없기 때문에 일반적으로 모터 부하를 일정 임피던스 부하로 취급하고 있다. 본 논문에서는 이러한 일반적인 방법으로 해결할 수 없는 개별부하의 특성을 고려해야만 하는 산업용 전력계통의 경우 모터의 동적 특성을 고려하여 안정도 해석을 수행하여 안정도 해석에 있어서 모터의 영향을 보였다. 대상은 실 계통인 광양제철소의 전력계통이며 3상고장에 의한 모터부하의 영향을 분석한다.

• 전기의세계
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• 제24권5호
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• pp.67-71
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• 1975

A dynamic stability analysis of a large interconnected power system takes much time even though the modern large computer is used because of the high order of the system dynamic equations. By the necessity of the low order power system models, a simplified power system model of the generator with the high speed solid state exciter is developed in this paper. The usefulness of the reduced model is confirmed by comparing its eigenvalues and the transient responses with those of the original model in the single machine to infinite bus power system.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1992년도 추계학술발표회논문집
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• pp.32-36
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• 1992

This paper develops the dynamic equivalents program combined with graphic user interface(GUI), to solve the stability of large power system. The p개posed method is coherency-based dynamic equivalents for transient stability studies. The program also provides with pull-down menu and Hangout help information for users. The developed dynamic equivalents program is suitable for the transient stability studies of a large power system with lots of data. The dynamic equivalents demonstrated over the New England system with 39 buses and 10 generators.

• 대한전기학회논문지:전력기술부문A
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• 제52권6호
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• pp.295-300
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• 2003

Voltage instability has been studied for some decade now. But, There is not generally accepted definition of voltage instability because of the complex phenomenon and the variety of ways in which it can manifest itself. Both IEEE and CIGRE have the respective definitions. The areas of voltage instability research are the analysis, simulation and countermeasure of voltage instability. It needs to model the components of the power system to simulate the voltage instability and voltage collapse. At the beginning, the static simulation was used. This method provides the voltage stability indices and it requires less CPU resource and gives much insight into the voltage and power problem. However, it is less accurate than the dynamic simulation peformed in the time domain simulation. So, when it appears difficult to secure the voltage stability margin in a static stability, it is necessary to perform the dynamic simulation. To perform time-domain simulation, we have to model the dynamic component of the power system like a generator and a load. The dynamic simulation provides the accurate result of the voltage instability. But, it is not able to provide the sensitivity information or the degree of stability and it is time consuming and it needs much CPU resource. In this Paper, we perform a dynamic simulation of voltage instability and voltage collapse using EMTP MODELS. The exponential load model is designed with MODEIS and this load model is connected with test power system. The result shows the process of voltage change in time domain when the voltage instability or voltage collapse occurs.

• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.495-505
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• 2008

This paper describes modeling Voltage Sourced Inverter (VSI) type Flexible AC Transmission System (FACTS) controllers and control methods for power system dynamic stability studies. The considered FACTS controllers are the Static Compensator (STATCOM), the Static Synchronous Series Compensator (SSSC), and the Unified Power Flow Controller (UPFC). In this paper, these FACTS controllers are derived in the current injection model, and it is applied to the linear and nonlinear analysis algorithm for power system dynamics studies. The parameters of the FACTS controllers are set to damp the inter-area oscillations, and the supplementary damping controllers and its control schemes are proposed to increase damping abilities of the FACTS controllers. For these works, the linear analysis for each FACTS controller with or without damping controller is executed, and the dynamic characteristics of each FACTS controller are analyzed. The results are verified by the nonlinear analysis using the time-domain simulation.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.402-410
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• 2013

In this paper, a novel and robust Power System Stabilizer (PSS) is proposed as an effective approach to improve stability in electric power systems. The dynamic performance of proposed PSS has been thoroughly compared with Conventional PSS (CPSS). Both the Real Coded Genetic Algorithm (RCGA) and Particle Swarm Optimization (PSO) techniques are applied to optimum tune the parameter of both the proposed PSS and CPSS in order to damp-out power system oscillations. Due to the high sufficiency of both the RCGA and PSO techniques to solve the very non-linear objective, they have been employed for solution of the optimization problem. In order to verify the dynamic performance of these devices, different conditions of disturbance are taken into account in Single Machine Infinite Bus (SMIB) power system. Moreover, to ensure the robustness of proposed PSS in damping the power system multi-mode oscillations, a Multi Machine (MM) power system under various disturbances are considered as a test system. The results of nonlinear simulation strongly suggest that the proposed PSS significantly enhances the power system dynamic stability in both of the SMIB and MM power system as compared to CPSS.

• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.451-456
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• 2009

Through the development of phasor measurement units (PMU), various aspects of power system dynamic behavior could be monitored and diagnosed. Monitoring dynamic voltage stability has become one of the achievements we can obtain from PMUs. It is very important to select the most appropriate method for the Korea Electric Power Corporation (KEPCO) system since there are many voltage stability indices. In this paper, we propose an advanced WAVI (Wide Area Voltage Stability) that is well suited for the purposes of monitoring the dynamic voltage stability of KEPCO's PMU installation plan. The salient features of the proposed index are: i) it uses only PMU measurements without coupling with EMS data; ii) it is computationally unburdened and can be applied to real-time situations. The proposed index is applied to the KEPCO test system and the results show that it successfully predicts voltage instability through comparative studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.54-60
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• 1994

The cause of black out of Tokyo Power in 1987 has been identified as the voltage stability problem. After this event many researchers has been interested in voltage stability or voltage collapse phenomena. The voltage instability is different Com the transient stability in the sense of reactive power mismatch and the long duration time. In this study, we developed efficient tool for analyze and control the dynamic voltage instability. To analize specific condition of dynamic voltage stability, quasi-dynamic simulation method is developed. To provide proper mathmatical model for dynamic voltage stability, generator, SVC, OLTC, induction motor models are introducted. To provide specified dynamic voltage stability, the authors considered to use reactive loss function(${\partial}Q/{\partial}p_L$) as reactive power facility control index. This program was tested and identified its usefulness in real KEPCO system.

• 에너지공학
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• 제11권3호
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• pp.194-202
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• 2002

본 논문은 객체지향 프로그램(OOP)을 사용하여 광양제철소 전력계통의 과도안정도를 모의한다. OOP는 절차식 프로그램보다 유연한 방법으로서 동적인 시스템의 모의에 여러 가지 장점이 있다. 시스템의 변화가 있으면 프로그램 전체을 수정하는 대신 필요한 부분만을 수정하면 되므로, 프로그램의 유지 및 보수가 매우 용이하다. 본 논문에서는 OOP를 이용하여 동적인 시스템의 해석을 위한 유연한 방법을 제시하였다. 시스템을 직접 사용자가 그려서 전력조류계산과 동적 안정도를 모의할 수 있는 사용자 인터페이스를 구현하여 17기의 동기발전기와 25기의 동기전동기로 구성되는 광양제철소 전력계통의 동적 안정도 해석에 적용하였다.