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김백(B. Kim) 한국철도학회 2004 한국철도학회 학술발표대회논문집 Vol.- No.-
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.
회생 차량의 전압 상승 한도를 고려한 AT 급전시스템 정태해석
김백(B. Kim),문영현(Y. H. Moon) 한국철도학회 2004 한국철도학회 학술발표대회논문집 Vol.- No.-
There are some previous studies that utilize constant impedance models or constant current models for electric trains to perform the static analysis of AT feeding systems. These mentioned models have some merits of linear systems but yield erroneous results because of the innate restraints of the models since linear models cannot represent the features of constant power in inverter-driven trains. From these reasons, it is suitable that the train be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However, excessive rise of regenerative voltage during the braking may damage the vehicle itself and the feeding systems so the voltage must be restricted below a certain value. Keeping these facts in minds, we suggest new methods of analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do.
김백(B. Kim),정광우(K. W. Chung) 한국철도학회 2005 한국철도학회 학술발표대회논문집 Vol.- No.-
Constant load model is generally used for an electric train to perform the static analysis of AT feeding systems. In this model, the train will be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However there must be some voltage constraints on the catenary in actual operations. These constraints are established for the reason of protecting the feeding facilities from excessive rise of regenerative braking voltage or guaranteeing the minimum traction power of train. In normal operating situation, the pantagraph voltage of the train should be maintained within these limits. Keeping these facts in minds, we suggest new methods of analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do. The proposed methods are believed to contribute to the assessment of TCR-TSC for compensating reactive powers too.
김백(B. Kim),정광우(K. W. Chung),문영현(Y. H. Moon),안충훈(C. H. Ahn) 한국철도학회 2002 한국철도학회 학술발표대회논문집 Vol.- No.-
The conventional SCADA being used in the electric railway has the basic functions of remote controlling and system monitoring. Since the SCADA lacks the functions essential to the fault prevention and the system recovery, operators must depend on their intuition and experience to considerable extent. Visually integrated information offered by PIS contributes to the fast system recovery and the state judgment of the power system, and makes a novice be adapted for the operation easily. In this paper, we have studied the various functions and its feasibility that can be offered by PIS.
김백(B. Kim),문영현(Y. H. Moon),유헌수(H. S. Ryu),송경빈(K. B. Song),조연옥(Y. O. Cho),안충훈(C. H. Ahn) 한국철도학회 2001 한국철도학회 학술발표대회논문집 Vol.- No.-
The conventional SCADA adopted for the electric railway has the mere function of controlling and monitoring the hardware itself. Lack of the functions necessary for the fault prevention and the system recovery requires the operators to depend on their intuition and experience. To make up for these shortcomings of the conventional SCADA, PIS(power Information System) visually offers integrated information for the optimal operation of the power system by manipulating the raw data acquired from the SCADA. In this paper we have studied the variety of information and its feasibility that can be offered individually by PIS.