• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.12
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• pp.589-594
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• 2000

The fuzzy controllers have been applied to the power system stabilizer due to its excellent properties on the nonlinear systems. But the design process of fuzzy controller requires empirical and heuristic knowledge of human experts as well as many trial-and-errors in general. This process is time consuming task. This paper presents an parameters tuning method of the fuzzy power system stabilizer using the genetic algorithm and simulated annealing(SA). The proposed method searches the local minimum point using the simulated annealing algorithm. The proposed method is applied to the one-machine infinite-bus of a power system. Through the comparative simulation with conventional stabilizer and fuzzy stabilizer tuned by genetic algorithm under various operating conditions and system parameters, the robustness of fuzzy stabilizer tuned by proposed method with respect to the nonlinear power system is verified.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.11
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• pp.497-505
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• 2001

The power system stabilizer(PSS) is important for the suppression of low-frequency oscillation and the improvement of system stability. In this paper, An Adaptive Neurofuzzy-based Power System Stabilizer(ANF PSS) is proposed as the new PSS type. The proposed PSS employs a multi-layer adaptive network. The network is trained directly from the input and the output of the generating unit. The algorithm combines the advantages of the Artificial Neural Network(ANN) and Fuzzy Logic Control(FLC) schemes. Studies show that the proposed ANF PSS can provide good damping of the power system over the wide range of operating conditions and improve the dynamic performance of the system.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1168-1170
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• 1997

In this paper, the sliding mode-model following(SM-MF) power system stabilizer(PSS) including closed-loop feedback(CLF) for single machine system is extended to multimachine system. Simulation results show that the SM-MF multimachine stabilizer is able to achieve asymptotic tracking error between the reference model state and the controlled plant state at different initial conditions.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.671-677
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• 1999

In this paper, we have designed power system stabilizer (PSS) using object-oriented method. There are several types of power system stabilizer. A proportional-integral(PI) controller is very simple for practical implementation. Therefore it has been widely employed by the industry. The methods of obtaining the gains(Ki,Kp) of PI controller are root-locus method and sub-optimal regulator approach. But these methods are cannot be applicable to nonlinear system and faulted power system. So we proposed a new method which can be applied to nonlinear system by numerical analysis method. The method of dynamic system simulation by numerical method is very difficult and complex. We proposed flexible simultaion method for complex power system analysis using object-oriented programming(OOP) and applied to PI controller design.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.900-902
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• 1997

Stabilization of Power systems is investigated using a proportional-integral power system stabilizer(PI PSS). Time division PI PSS is examined in this paper. Two approaches are presented for determining the optimal stabilizer gains of the proposed PI PSS. Simulation results show that the proposed PI PSS yields better system dynamic performance and stability than the sub-optimal stabilizer in the sense of having greater damping in response to a step disturbance.

• Progress in Superconductivity
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• v.7 no.1
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• pp.83-86
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• 2005

The High-Tc superconducting power cable consists of a multi-layer high-Tc superconducting cable core and a stabilizer which is used to bypass the current at fault time. Eddy current loss is generated in the stabilizer in normal operating condition and affects the whole system. In this paper, the eddy current losses are analyzed with respect to various structure of stabilizer by using opera-3d. Moreover, optimal conditions of the stabilizer are derived to minimize the eddy current losses from the analyzed results. The obtained results could be applied to the design and manufacture of the high-Tc superconducting power cable system.

• Journal of Power System Engineering
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• v.9 no.3
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• pp.44-49
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• 2005

The aerodynamic performance of an indoor room air-conditioner using a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this study is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance in the maximum flowrate range of a cross-flow fan. The design factors considered in this study are a rear-guider clearance, a stabilizer cutoff clearance, and a stabilizer setup angle, respectively. Aerodynamic performances including maximum flowrate and power show the biggest magnitude distribution in the case of $45^{\circ}$, the stabilizer setup angle as well as nearly similar magnitude distribution regardless of the stabilizer cutoff clearances. Moreover, the more a rear-guider clearance increases, the more the magnitude of maximum flowrate and power increases.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.10
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• pp.479-485
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• 2000

This paper presents a analysis method for dynamic characteristics of power system using a Genetic-based Power System Stabilizer(PSS). The proposed PSS parameters are optimized using Genetic Algorithm(GA) in order to maintain optimal operation of generator under the various operating conditions. To decrease the computational time, real variable string is adopted. The results tested on a single machined infinite bus system verify that the proposed controller has better dynamic performance than conventional controller.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.84-86
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• 2005

Adaptive tracking, disturbance rejection and power system stabilizer. First, this paper deals with power system stabilization problem using asymptotic tracking of arbitrary smooth bounded reference output signals, with simultaneous rejection of disturbances generated by an unknown linear exosystem. Second, this paper presents a power system stabilizer(PSS) using nonlinear adaptive observer backstepping controller.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.683-691
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• 1999

In this paper, it is suggested that the selection method of optimal parameter of power system stabilizer(PSS) with robustness in low frequency oscillation for power system using Real Variable Elitism Genetc Algorithm(RVEGA). The optimal parameters were selected in the case of power system stabilizer with one lead compensator, and two lead compensator. Also, the frequency responses characteristic of PSS, the system eigenvalues criterion and the dynamic characteristic were considered in the normal load and the heavy load, which proved usefulness of RVEGA compare with Yu's compensator design theory.