• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.892-897
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• 2007

This paper presents the output filter design and the output characteristic analysis by cut-off frequency set up of the LCR filter on NPC multi-level inverter with trap-filter. The single-phase NPC three-level inverter operates at low switching frequency. The proposed LC trap filter is comprised of a conventional LCR output filter, by using LC trap filter the need for high damping resistor and low LC cut-off frequency is eliminated. Also. low damping resistor is increased the output filter system. The multilevel inverter system used NPC type inverter in proper system for high power application and controller is used DSP(TMS320C31). The effectiveness of proposed system confirmed the validity through SPICE simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.123-125
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• 2008

This paper deals with output voltage characteristics analysis of outage and phase jump generator. As soon as the outage occurs the STS(Solid Transfer Switch)s are switched off. At the beginning of the outage the DG is required to limit the reverse current within the rated DG output current. In case of phase jump the DG output voltage phase should be adjusted with PLL. Simulation results show the output voltage characteristics of the generator.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.106-108
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• 2008

This paper describes output characteristics analysis of outage and phase jump generator for microgrid. The outage and phase jump can be generated with 3-phase voltage disturbance generator. As soon as the outage occurs the STS(Solid Transfer Switch)s are switched off. At the beginning of the outage the PCS is required to limit the reverse current within the rated PCS output current. In case of phase jump the PCS output voltage phase should be adjusted. The generator output characteristics are analysed through simulation.

• Current Photovoltaic Research
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• v.5 no.1
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• pp.38-42
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• 2017

PV system output is determined according to the weather conditions, the azimuth and tilt angle. Weather conditions are changing every moment and it seems to vary according to the daily, monthly, and annual basis. The azimuth and tilt angle is decided along the site conditions for the PV system installation. This paper analyzed the PV system output through the changing the weather conditions, the azimuth, and tilt angle. We compared the TMY data and analysis of the two major weather institutes which are KMA and METEONORM. PV system output trend were analyzed by changing the azimuth and tilt angle. We used simulation tool, which is named PVsyst for the entire PV system analysis.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.255-261
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• 2021

This paper proposes impedance-based stability analysis of DC-DC boost converters, where a harmonic state space (HSS) modeling technique is used. At first, the HSS model of the boost converter is developed. Then, the closed-loop output impedance of the converter is derived in frequency domain using small signal modeling including frequency couplings, where harmonic transfer function (HTF) matrices of the open-loop output impedance, the duty-to-output, and the voltage controller are involved. The frequency response of the output impedance reveals a resonance frequency at low frequency region and frequency couplings at sidebands of switching frequency which agree with the simulation and experimental result.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.436-436
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• 1994

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.65-74
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• 1994

In the steady-state simulation, it is important to identify initialization bias for the correct estimates of the simulation model under study. In this paper, the methods from chaos theory are applied to the determination of truncation points in the simulation data for controlling the initial bias. Two methods are proposed and evaluated based on their effectiveness for estimation the average waiting time in M/M/1($\infty$) queueing model.

• Journal of the Korea Society for Simulation
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• v.5 no.2
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• pp.59-72
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• 1996

The purpose of this study is to make an improvement to the batch-means method, which is a procedure to construct a confidence interval(c.i.) for the steady-state process mean of a stationary simulation output process. In the batch-means method, the data in the output process are grouped into batches. The sequence of means of the data included in individual batches is called a batch-menas process and can be treated as an independently and identically distributed set of variables if each batch includes sufficiently large number of observations. The traditional batch-means method, therefore, uses a batch size as large as possible in order to. destroy the autocovariance remaining in the batch-means process. The c.i. prodedure developed and empirically tested in this study uses a small batch size which can be well fitted by a simple ARMA model, and then utilizes the dependence structure in the fitted model to correct for bias in the variance estimator of the sample mean.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.349-354
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• 1999

Electro-Optical Camera (EOC) is the main payload of the KOMPSAT-1 satellite to perform the mission of cartography that builds up a digital map of Korean territory including a digital terrain elevation map. This paper discusses the issues of the digital image simulation of EOC for the generation of EOC simulated scene as taken by EOC at 685km altitude on orbit. For the purpose, simulation work has been performed with the sensor models of EOC and the satellite platform motions models through image chain analysis from the illumination source (Sun) to a simulated image output in digital number. MODTRAN fur radiance calculation, MTF models of optics, detector and motions of EOC for system point spread function (PSF), and signal chain equations for digital number output are described. Several noise models of EOC are also considered. The final output is the EOC simulated image in digital number. The simulation technique can be used in several phase of a spaceborne electro-optical system development project, feasibility study phase, design, manufacturing, test phases, ground image processing phases, and so on.

• Journal of Power Electronics
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• v.8 no.1
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.