• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.223-226
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• 2004

This paper describers the power demand and the voltage stability in power system. Especially the power demand on summer is more and more increase in korea. According to load quantity is increasing voltage is getting down. And power system becomes unstable. So this paper is prevent voltage down using to ULTC modeling which is a part in a transformer. Therefore our purpose is power system stability increasing as variable state like a load increasing or a fault. Then this paper is using IPLAN and PSS/E as analysis tool. PSS/E is very powerful engine on load flow analysis. And IPLAN is capable of using on variable program compiling with user.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.796-801
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• 2011

The objective of this work presented here was focused on analysis of development trend for the integrated power system of naval vessels to perform the high-power and energy mission load platform. These mission loads are affected by the high level of military technologies, digitalization of the ocean battlefield, high power sensor system for maximization of the ship survivability. All electric power including propulsion power for ship should be controlled by integrated single system in order to carry various high power density weapon system such as Electromagnetic Aircraft Launch System, Electromagnetic Rail Gun[feasible precision striking at long distance 200NM(370km) or over]. As the analyzing the present state of things, mechanical propulsion system is shifted into hybrid or fully electric propulsion systems to realize integrated power system at the developed countries. Such challenges include reduced dependency on foreign-supplied fossil fuel, increasing demand for installed ship power, controlling life-cycle costs.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1289-1302
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• 2019

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.134-135
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• 2003

Abstract in case of the small scale power system separated from large scale power system N-2 contingency, the Over excitation, Under Frequency and Power swing Tripping Relay operate depending on unbalance Of Generation and Load. and then we studied and measured the angle and frequency deviation between generators. moreover, we compared real fault example with simulation results.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.21-30
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• 2001

The analysis system implementing a serial process from structural vibration to sound radiation has been developed using both the power flow finite element method (PFFEM) known as a new vibrational analysis technique in medium to high frequency ranges and the acoustic boundary element method (BEM) which is effective in analyzing the sound radiation problems. The vibration analysis for arbitrary shape structures composed of plates is performed, and using the vibration energy density obtained from this analysis as the velocity boundary conditions for an acoustic analysis, vibro-acoustic analysis has been processed. To verify the developed system, we select a simple structure model and compare the results of developed system with those of SYSNOISE, and also the developed system is applied for the vibro-acoustic analysis of various structures in shapes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.155-163
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• 2008

This paper presents a novel framework for analysis of power system wide-area blackout based on so called fault cascading scenarios. For a given power system operating state, "triggering" faults or a "seed faults" are chosen based on the probabilities estimated from the hazard rates. The fault probabilities reflect both the load and the weather conditions. Effects of hidden failures in protection systems are also reflected in establishing the fault propagation scenarios since they are one of the major causes for the wide-area blackouts. A tree type data structure called a PS-BEST(Power System Blackout Event Scenario Tree) is proposed for construction of the fault cascading scenarios, in which nodes represent various power system operating states and the arcs are the events causing transitions between the states. Arcs can be either probabilistic or deterministic. For a given initial fault, the total probability of leading to wide-area blackout is estimated by aggregating the individual probability of each fault sequence route leading to wide-area blackout. A case study is performed on the IEEE RTS-79(24 bus) system based on the fault data presented by the North American Electrical Reliability Council(NERC). Test results demonstrate the potentials and the effectiveness of the proposed technique for the future wide-area blackout analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.873-878
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• 2009

When the transmission lines are initially energized for power system restoration, the power system suffers the various overvoltages that can be classified as steady-state, transient, and dynamic overvoltages. For the accurate analyses of these overvoltages, many researchers utilize different simulation tools such as Power System Simulator for Engineering(PSS/E). Although PSS/E provides good solutions in steady-state and dynamic overvoltages, it is not suitable for transient overvoltages. Therefore, transient overvoltages are simulated by using Electro-Magnetic Transients Program(EMTP) developed for the analysis of transients in the power system. Recently, EMTP can be also used to simulate dynamic behavior of the system. In order to analyze the transient overvoltages with steady-state and dynamic overvoltages, the authors adopt EMTP as the simulation tool for the analysis of overvoltages. This paper presents the simulation results for the analyses of various overvoltages, and the possibility of EMTP to be used for these types of analyses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.878-884
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• 2015

In this paper, Power Management System(PMS) simulator for Liquid Nature Gas Carrier(LNGC) is developed. Major components of power system for LNGC, such as generator, diesel engine and governor, transformer, circuit breaker, and 3 phase loads models are built based on MATLAB/SIMULINK. With these designed major parts, PMS simulator modeling is carried out. Based on MATLAB/Graphical User Interface, PMS simulator control for LNGC, and Human Machine Interface for monitoring is designed. PMS simulator for LNGC carries out simulation according to sequence of characteristics analysis. By comparing results of predicted simulation for each sequence to that of characteristics analysis, the reliability of PMS simulator for LNGC will be verified.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.12
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• pp.435-440
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• 1983

The methods of forming the bus impedance matrix, which is mainly employed in fault analysis of power system, can be generally classified in catagories, (1) the one being the inverse matrix of bus admittance matrix, and (2) the other the bus impedance matrix succesive formation method by particular algorithms. The former method is theouetically elegant, but the formation and inverse of complex bus admittance matrix for large power system requires too much amounts of computer memory space and computing time. The latter method also requires too much memory space. Therefore, in this paper, an algorithm and computer program is introduced for the formation of a sparse bus impedance matrix which generates only the matching terms of the admittance matrix. So, this method can reduce the computer memory and computing time, and can be applied to fault analysis of large power system by small digital computer.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.5
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• pp.573-580
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• 2014

The electrical reliability of the power generation and distribution system of Floating Liquefied Natural Gas vessels has been analyzed according to the operating modes using Electrical Transient Analysis Program in this paper. Electricity is used for the topside processes, cargo pumps for off-loading, thrusters for heading control and marine equipment. It is very important to improve the safety, efficiency, and stability of the electrical power system for successful operation. The voltage variation of the high and the low voltage bus shall be within the primitive limitation range at normal operation loads both in steady state and in the transient state. The power system was simulated and compared with class rule for design verification.