• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.331-337
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• 2015

The power flow analysis of electrified railway is required complicated calculation, because of variable load. Train runs trough rail supplied by electric power therefore, the load value in electrified railway system fluctuates along time. The power flow algorithm in electrified railway system is different from general power system, and the power flow simulation is peformed by the particular simulation software. Powerail is simulation software for analysis of traction power supply system developed by KRRI, in 2008. This consists of load forecasting module, including TPS and time scheduling, and power flow module. This software was verified by measured current under normal feeding condition, however, has not been verified by voltage on the condition of extended feeding. This paper presents the verification of PowerRail based on voltage drop under extended feeding condition. This is performed by comparing simulation result with field test. Field test and simulation is done in commercial railway line.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.842-850
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• 2021

Real Time Simulation (RTS) has long been used in the nuclear power industry for operator training and engineering purposes. And, Online Simulation (OLS) is based on RTS and with connection to the plant information system to acquire the measurement data in real time for calibrating the simulation models and following plant operation, for the purposes of analyzing plant events and providing indicative signs of malfunctioning. An OLS system has been developed to support PWR operations for CPR1000 plants. The OLS system provides graphical user interface (GUI) for operators to monitor critical plant operations for preventing faulty operation or analyzing plant events. Functionalities of the OLS system are depicted through the maneuvering of the GUI for various OLS functional modules in the system.

• KIEE International Transactions on Power Engineering
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• v.3A no.2
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• pp.93-99
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• 2003

This paper deals with the development and testing of a large-scale, realtime digital power system simulator for the Korean Electric Power Corporation. The KEPS Simulation Center is located at KEPCO's research center (KEPRI) in Taejon, South Korea and has been operated since September 2001. The KEPS Simulation Center includes a wide range of off line power system simulation and analysis tools, as well as an advanced realtime digital simulator for the study of large scale AC and DC system performance. Because the application scope of the KEPS realtime simulator is broad and because the network models being considered are significantly larger and more complex than in traditional realtime simulator applications, many developments and tests have been required during the course of the project. In this paper, the authors describe some of these developments and present results from various benchmark tests that have been performed.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.171-173
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• 2002

This paper presents a power system decomposition technique for digital simulation of large power system. To decompose power system, distributed transmission line model is used. But this model can be used only for long transmission lines. In this paper, capacitor compensation method is proposed to use distributed transmission line model for short transmission line. And case study shows proposed method can be used for effective power system decompositon in digital simulation of large power system.

• Journal of Power Electronics
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• v.11 no.2
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• pp.202-210
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• 2011

Polymer electrolyte membrane (PEM) fuel cell is one of the popular renewable energy sources and widely used in commercial medium power areas from portable electronic devices to electric vehicles. In addition, the increased integration of the PEM fuel cell with power electronics, dynamic loads, and control systems requires accurate electrical models and simulation methods to emulate their electrical behaviors. Advancement in parallel computation techniques, various real-time simulation tools, and smart power hardware have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds up advancements of optimized model constructions for a fuel cell stack system on a real-time simulator in the view points of improving dynamic model accuracy and boosting computation speed. In addition, several considerations for a power hardware-in-the-loop (PHIL) simulation are provided to electrically emulate the PEM fuel cell stack system with power facilities. The effectiveness of the proposed PHIL simulation method developed on Opal RT's RT-Lab Matlab/Simulink based real-time engineering simulator and a programmable power supply is verified using experimental results of the proposed PHIL simulation system with a Ballard Nexa fuel cell stack.

• Journal of Power System Engineering
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• v.15 no.2
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• pp.5-12
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• 2011

In this study, modeling and numerical simulations has been performed to investigate performance characteristics of constant power regulator system for swash plate type axial piston pump. The commercial numerical simulation software, AMESim was applied for analyzing the dynamic behavior of constant power regulator system of swash plate axial piston pump. The validity of simulation model of constant power regulator system is verified by comparing simulation results with experiments. Also, the behavior of main components of constant power regulator system such as spool, sleeve and counterbalance piston is investigated using the results of computer simulation.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.21-29
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• 1995

The automotive transmission is the principal component of the power transmission system which converts the engine power into the adjustable power for the vehicle driving system. To the unskilled driver the automization of transmission is required for the safety and fuel economy. In this study, the dynamic model of the automotive power transmission system was presented and simulation program and interface board which interface IBM-PC with ECU was devloped. Through the traveling simulation by interfacing ECU with simulation program, the shifting transients are investigated. For verification of simulation experiment was carried out, the results of simulation was agreed well with those of simulation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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• pp.169-177
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• 2014

Operation and control system has been installed and tested to use energy storage system(ESS) for frequency regulation at 4MW class of ESS demonstration facility installed at Jeju island, Korea in 2013. Simulation tests were performed by programing language C# for power system of Jeju island to develop control algorithm. Site simulation tests were performed in control system itself without connecting power system and energy storage system. Control algorithm was coded, modified and tested to load to controller and communication system and human-machine interface were developed and tested in the process of simulation tests. After similar results to that of simulation tests by programing language were obtained, power system and energy storage system demonstration facility were connected to control system by communication system. Energy storage system for frequency regulation was tested for actual frequency and simulation frequency. The site tests showed the similar results to that of simulation tests and the control systems is possible to be operated for frequency regulation. Faster response of energy storage system for frequency regulation, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. It is expected that more studies for time-reduction and time-delay elements can make less capacity of energy storage system cover more role of frequency regulation of power plants.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.472-477
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• 2013

An internet-based, real-time GPS synchronized wide-area power system frequency monitoring network(FNET) has been monitoring wide-area power system frequency in continuous time in the United States. This paper analyzes the FNET measurement to the verified disturbances in the US eastern interconnected power system and simulates it using the dynamic system model. By comparing the frequency measurements with its simulation results to the same disturbances in detail, this paper finds that the sequence of monitoring points to detect the frequency fluctuation caused by the disturbances is matched well in the measured data and the simulation results. The similarity comparison index is also proposed to quantify the similarity of the compared cases. The dynamic model based simulation result is expected to compensate for the lack of FNET measurement in its applications.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.4
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• pp.436-443
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• 2015

In order to develop the PHEV(plug-in hybrid electric vehicle), the specific power transmission systems considering the PHEV system characteristics should be applied. A PHEV applied to series-parallel type hybrid power transmission system is a typical example. In this paper, the novel hybrid power systems are proposed by analyzing the existing PHEV system. The backward simulation program is developed to analyze the fuel efficiency of hybrid power system. Quasi-static models for each components such as engine, motor, battery and vehicle are included in the developed simulation program. To obtain an optimal condition for hybrid systems, an optimization approach called the dynamic programming is applied. The simulation is performed in various driving cycles. A weakness for the existing system is found through the simulation. To compensate for a discovered weakness, novel hybrid power systems are proposed by adding or moving the clutch to the existing system. Comparing the simulation results for each systems, the improved fuel efficiency for proposed systems are verified.