• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.301-304
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• 2001

Wind power generation system is one of the most useful energy resource using natural environment. One of the biggest problem we encountered is toot the wind speed is fluctuating sharply according to the weather conditions rather than it is stable. In this paper we do the equivalent modeling the mechanical energy of wind power turbine according to wind speed into the synchronous generator. We analyse the equivalent modeling output part of rectifier into DC/DC converter input part theoretically. We analyse a battery charging characteristics for power storage enabling the supply of stable power to the load. We design a system and do the modeling of it analytically so that it supplies a stable power to the load by constructing a DC-AC inverter point. Also we make a small size model usable in actual wind power generation system of 30kw and make an experiment and confirm its validity.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.15-24
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• 2000

The dielectric relaxation of high-dielectric capacitors could be understood as a dynamic property of the capacitor in the time domain, which is regarded as a primarily important charge loss mechanism during the refresh time of DRAMs. Therefore, the equivalent circuit of the dielectric relaxation of the high-dielectric capacitor is essentially required to investigate its effects on DRAM. Nevertheless, There is not any theoretical method which is generally applied to realize the equivalent circuit of the dielectric relaxation. Recently, we have developed a novel procedure for the circuit modeling of the dielectric relaxation of high-dielectric capacitor utilizing the frequency domain. This procedure is a general method based on theoretical approach. We have also verified the feasibility of this procedure through experimental process. Finally, we successfully investigated the effect of dielectric relaxation on DRAM operation with the obtained equivalent circuit through this new method.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.197-199
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• 2002

The invention of VHDL(Very High Speed Integrated Circuit Hardware Description Language), Technical language of Hardware, is a kind of turning point in digital circuit designing, which is being more and more complicated and integrated. Because of its excellency in expression ability of hardware, VHDL is not only used in designing Hardware but also in simulation for verification, and in exchange and conservation, composition of the data of designs, and in many other ways. Especially, It is very important that VHDL is a Technical language of Hardware standardized by IEEE, intenational body with an authority. The biggest problem in modern circuit designing can be pointed out in two way. One is a problem how to process the rapidly being complicated circuit complexity. The other is minimizing the period of designing and manufacturing to survive in a cutthroat competition. To promote the use of VHDL, more than a simple use of simulation by VHDL, it is requested to use VHDL in composing logical circuit with chip manufacturing. And, by developing the quality of designing technique, it can contribute for development in domestic industry related to ASIC designing. In this paper in designing SMPS(Switching mode power supply), programming PWM by VHDL, it can print static voltage by the variable load, connect computer to chip with byteblaster, and download in Max(EPM7064SLCS4 - 5)chip of ALTER. To achieve this, it is supposed to use VHDL in modeling, simulating, compositing logic and product of the FPGA chip. Despite its limit in size and operating speed caused by the specific property of FPGA chip, it can be said that this method should be introduced more aggressively because of its prompt realization after designing.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.2
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• pp.39-45
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• 2002

A new EMI estimation technique concerned with a PDP system is presented. A physical circuit model is developed which can fairly well describe the AC-PDP system. EMIs of the PDP system are quantitatively determined by combining circuit model and Hertzian dipole antenna model. The simulation results are experimentally verified with the test panel. The AC PDP system was measured in the frequency range of 30MHz~300MHz in a semi-anechoic chamber, according to CISPR 13 code. Thereby, it is shown that the proposed technique can be usefully employed for EMI reduction.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.10
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• pp.1091-1096
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• 2009

Some closed-form expressions for circuit parameters are derived based on the equivalent circuits for the resonant MTM-TL(open and short). The lumped series resistance and shunt conductance, which explain radiation effects of a unit cell may be found by |$S_{11}$|(simulated or measured) with open and short terminations, respectively. The EM-simulated results, circuit-simulated results(obtained using extracted circuit parameters) and measurement results are shown to be in good agreement.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.3
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• pp.320-330
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• 2012

In this paper, we investigate the power integrity of grid structures for power and ground distribution on printed circuit board (PCB). We propose the 2D transmission line method (TLM)-based model for efficient frequency-dependent impedance characterization and PCB-package-integrated circuit (IC) co-simulation. The model includes an equivalent circuit model of fringing capacitance and probing ports. The accuracy of the proposed grid model is verified with test structure measurements and 3D electromagnetic (EM) simulations. If the grid structures replace the plane structures in PCBs, they should provide effective shielding of the electromagnetic interference in mobile systems. An analytical model to predict the shielding effectiveness (SE) of the grid structures is proposed and verified with EM simulations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1286-1291
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• 2018

In recent years, the proliferation of DER (distributed energy resources) is progressing rapidly. In particular, research on LVDC distribution grid with various advantages has begun. In order to commercialize this LVDC grid, direct current protection method should be established by analysis of DC faults. Recently, the development of HSCB (high-speed circuit breaker) for new ${\pm}750[V]$ LVDC grid has been researched. This paper deals with the calculation of the maximum short-circuit fault current of the HSCB as a part of the development of HSCB for the LVDC distribution grid. First, modeling using PSCAD was carried out for PV array with BESS on the Gochang Power Test Center system. Next, to calculate the rated capacity of HSCB, fault currents were calculated and the characteristics were analyzed through fault simulations. Thus, this study results can help to establish short-circuit capacity calculation of HSCB and protection plan for DC protection relay system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.9
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• pp.59-64
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• 2015

IEC is an international standards which are used in many countries with Europe as the center. IEC standard is introduced in Korea according to WTO/TBT agreements, however until now there are no buildings in Korea which are designed applying IEC standard. Therefore, KEA(Korea Electric Association) is scheduled to construct Korean low voltage electrical installation integration test site which is designed applying IEC standard. In this paper, before being under construction of Korean low voltage electrical installation integration test site, power substation is modeled based on real design parameters and method to select circuit breakers and cables is presented applying IEC standard in the modeled power substation. EMTP(ElctroMagnetic Transient Program) is used for simulation program. EMTP which is power system analysis program is easy to model power system and power substation.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2046-2051
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• 2015

Currently, most high-voltage gas circuit breakers (CBs) include asymmetrical geometries in the shield, the tank, the hot-gas exhaust, and the connection parts for bushings. For this reason, a 3-dimensional (3-D) analysis of the insulation capability is necessary, rather than a 2-D analysis. However, a 3-D analysis has difficulties due to the computational time and complex modeling. This paper presents a 3-D analysis considering the asymmetry in high-voltage gas CBs and a technique to reduce the calculation time. In the proposed technique, the arc plasma requiring the most computational time is first calculated by a 2-D analysis. Then, the results such as pressure, temperature, and velocity are input as a source for the 3-D analysis. This technique is applied to a 145kV self-blast-type CB and the analysis result exhibits good agreement with the experimental result.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.6
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• pp.653-658
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• 2015

In this paper, the Square Split Ring Resonator(: SRR) of Defected Ground Structure(: DGS), applicable to MMIC(: Monolithic Microwave Integrated Circuit) design, is proposed. The mathematical method to solve the equivalent parameter of the resonator from the measured results of resonator is introduced in this paper. To verify the method, SRR-DGS resonator with 2.95 GHz center frequency is fabricated, for measuring characteristics and calculating the equivalent parameter. The result from this process is compared with the data of the ADS simulation, and as a result both were identical.