• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.56-59
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• 2007

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.45-48
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• 2004

To improve the efficiency characteristics in the resonant converter using the contact-less power supply with the large air-gap and the long primary winding, this paper suggests the three-level series-parallel resonant converter(SPRC). The voltage gain characteristics of the proposed converter have the unit gain in a resonance frequency point of the series and parallel, and input voltage and current in the primary of SPRC are always In phase for the all equivalent load resistance because of the parallel resonant tank of the high impedance. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental prototype.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1675-1680
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• 2011

Inductive power transfer module(IPTM) is a contact-less power supply device and its application range has been extended to the large capacity devices such as electric vehicles, industrial mover and railway system as well as small capacity devices such as electric toothbrush charger, celluar phone charger, and so on. For railway application, the IPTM will transfer energy while train stops at a station for around 30[sec]. Therefore, equivalent circuit parameters and coupling coefficient of IPTM are an important design factor for the high energy transfer efficiency. This paper investigates the properties of equivalent circuit parameters and coupling coefficient of U-U type IPTM and U-I type IPTM using an analytical method and experimental method. Considering the coupling coefficient of the U-U type is larger than U-I type's, the U-U type is suitable for an application which need maximum power transfer and high efficiency.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.574-576
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• 2008

Now there are two types Non-contact compensation AC automatic voltage regulator (A.V.R). One is transformer compensation regulator, whose principle is the combination of multiple compensation transformers, do the compensation by turning on and off the connections of the transformer through the multi-full bridge circuit. This method removed the mechanical drive and contacts, which increases the life and the dynamic performance of the A.V.R. However, the compensation is multilevel, and it needs many compensation transformers and switches, the circuit is complex, the compensation precision is low. Another type is PWM switch AC regulator, whose principle is getting the AC voltage from the input, then induce the AC compensation voltage through commutating and high frequency PWM transforming, and phase tracking. Here the compensation is step-less, the compensation precision is high, and the response is fast. But the circuit is complex, and it needs an inverse compensation transformer, which is difficult to realize high-power applications. In this paper, it shows an Automatic Voltage Regulator which use high frequency PWM inverter do compensation. This A.V.R has the function as the custom-power, which make the performance of the power supply in a high level.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1163-1168
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• 2013

The maximum allowable value of loop impedance($Z_s$) to secure the operation of overcurrent protective devices and the safety for indirect contact is a very important in TN-C-S system. The loop impedance is divided into inner loop impedance which consumer can adjust and external loop impedance($Z_e$) which only electric operator can adjust. Thus, an external loop impedance which limits to less than a certain value is a very important factor for human body protection against electric shock in TN-C-S system. The concept of loop impedance($Z_s$) is recently introduced to the domestic, the study about external loop impedance is yet insufficient. However, the study about the reference impedance as specified by the IEC 60725 standard to improve the quality and reliability of the power supply is being made. In this paper, reference value of external loop impedance($Z_e$) to meet domestic environment will be proposed by the nationwide measurement and statistical analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1302-1307
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• 2011

The Spiral coil is made considering primary, secondary side coil inductance, turn number, size, thickness, and shielding area with the litz wire-type in case of manufacturing a coil, and at this time, the semi-automation winding machine is used. When deciding on primary and secondary side coil specification and manufacturing a coil, the spiral coil of a specification varied in the various litz wire of a specification is required, and at this time, a difficulty is generated by the manufacture cost, period which during, and failure the manufacture is generated in the coil sample making. A difficulty is in the desired coil quality control of a specification. Since improving the rectifier of the secondary side in order to improve this kind of problem, the range of the coil design and the during the manufacture, various coil manufacture specifications can be comprehensively made.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.6
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• pp.527-534
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• 2015

This study offers a novel method for improving the physical contact between the anode and fuel in a direct carbon fuel cell (DCFC): a direct generation of carbon in a porous Ni anode through the thermal decomposition of gaseous hydrocarbons. Three kinds of alkane hydrocarbons with different carbon numbers (CH4, C2H6, and C3H8) are tested. From electron microscope observations of the carbon particles generated from each hydrocarbon, we confirm that more carbon spheres (CS), carbon nanotubes (CNT), and carbon nanofibers (CNF) were identified with increasing carbon number. Raman scattering results revealed that the carbon samples became less crystalline and more flexible with increasing carbon number. DCFC performance was measured at $700^{\circ}C$ with the anode fueled by the same mass of each carbon sample. One-dimensional carbon fuels of CNT and CNF more actively produced and had power densities 148 and 210 times higher than that of the CS, respectively. This difference is partly attributed to the findings that the less-crystalline CNT and CNF have much lower charge transfer resistances than the CS.