• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.4
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• pp.153-153
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• 1985

A method of computer aided design (C.A.D.) is proposed to analize a load circuit of a high frequency induction heating. Various formulas are derived from the properity of the heating load, which is useful for the design of heating materials. A load circuit which is designed by the proposed C.A.D. is realized and tested. The experimental results show in good agreement with the theoritical analysies. Especially the result reveal that the power transfer efficiency increases as the Q and coupling coefficient of the work coil increase.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1333-1334
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• 2006

중, 저압 배전 시스템을 통신망으로 사용하는 전력선 통신(PLC, Power Line Communication)에서 신호결합은 하드웨어 측면에서 매우 중요하다. 본 논문에서는 2-40MHz의 통신 신호를 수백 A의 전류가 흐르는 배전선으로 보내고 추출하는 유도성 신호결합장치와 통신신호 손실에 대하여 조사하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.497-498
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• 2011

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.8
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• pp.798-804
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• 2013

In this paper, conducted emission from the LDC(Low-Side DC/DC Converter) of a HEV/EV was analyzed using high-frequency circuit modeling in system-level approach. The conducted emission by PWM process(100 kHz; Switching Frequency) can cause RFI(Radio-Frequency Interference) problems in the AM/FM frequency range. In order to mitigate this conducted emission, a high-frequency equivalent circuit model is proposed by analyzing the fundamental circuits, parasitic components in their parts and connections and non-linear characteristics of MOSFETs, high-power capacitors, inverters, motors, high-power cables, and bus bars which are composed of the LDC. Using these circuit models, results of both simulation and measurement were compared and similarities between them were verified. We are looking forward that this approach can be effectively used in the EMC design of HEV/EV.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.82-90
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• 2013

In this paper, conducted emission from the MDS(Motor Drive System) of a HEV/EV was analyzed using high- frequency circuit modeling in system-level approach. The conducted emission by PWM process can cause RFI(radio- frequency interference) problems in the AM/FM frequency range. In order to mitigate this conducted emission, a high-frequency equivalent circuit model is proposed by analyzing the fundamental circuits, parasitic components in their parts and connections and non-linear characteristics of IGBTs, high-power capacitors, inverters, motors, high-power cables, and bus bars which are composed of the MDS. It is confirmed that the simulated result by the proposed model is well agreed with measured results in spite of a large-scaled analysis in system level. We are looking forward that this approach can be effectively used in the EMC design of HEV/EV.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.1
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• pp.94-102
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• 2003

This paper describes the load parallel type full-bridge high frequency resonant inverter can be used as power source. Output control method of proposed circuit is compared with pulse frequency modulation(PFM), pulse width modulation(PWM) and pulse phase variation(Phase-Shift). The analysis of the proposed circuit is generally described by using the normalized parameters. The principle of basic operating and the its characteristics are estimated according to the parameters such as switching frequency(${\mu}$), pulse width($\theta$d) the variation of phase angle($\phi$) by three driving signal patterns. Experimental results are presented to verify the theoretical analysis result. In future, Characteristics by three driving signal control method is provided as useful data in case of output control of a power supply in various fields as induction heating application, DC-DC converter etc.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.5
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• pp.423-431
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• 2001

This paper proposes a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI-fed induction motor drives. The new active common mode voltage damper is consists of a four-level half-bridge Inverter and a common mode transformer with a blocking capacitor. In order to reduce the common mode voltage and high frequency leakage current the active common mode damper applies to the PWM inverter system the compensated voltage of which the amplitude is the same as the common mode voltage and of which the polarity is opposite to the common mode voltage. Simulated using P-SPICE and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.93-100
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• 2011

This study deals with the high frequency induction hardening (HF at $850^{\circ}C$, 120kHz & 50kW condition) SM45C steel. (1) The HF specimen, which was tempered at $150^{\circ}C$, did not show any tempering effect. A brittle fracture occurred at rounded area of the tensile specimen. AE (acoustic emission) amplitude distribution showed between 45dB and 60dB. (2) A slip and fracture occurred at the hole area of the HF specimen which was tempered at $300^{\circ}C$. As they pass the yield point, the AE energy is increased intermittently and AE amplitude distribution exists between 70dB and 85dB. In addition, after imposing the maximum tensile load, AE signals showed high amplitude and energy distribution. The AE amplitude showed between 45dB and 70dB. (3) A brittle fracture occurred at HF specimen which was tempered at $450^{\circ}C$ as if it is torn in the direction of $45^{\circ}$ on parallel area over the both sides of the tensile specimen, which lead to several peak appeared in AE energy. It was found that the AE amplitude was relatively low and the AE energy was high.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.8
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• pp.72-78
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• 2022

Bending using high-frequency induction heating is used to bend pipes and sections, and is currently widely applied in industrial fields such as power generation facilities, ships, onshore plants, and offshore plants. The purpose of this study is to study the manufacturing process and design technology of high-frequency bending of pipe to make the best pipe design arrangement. Although various studies are being conducted in the field of high-frequency bending, more research is needed on high-frequency bending of pipes for ship building and offshore plants. The purpose of this study is to review the feasibility of production design using 3D model tool of S3D and AM(PDMS), and to review and improve bending thickness reduction, reduction rate, and roundness.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.257-263
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• 2018

Hyperthermia supplies RF high-frequency energy above 1MHz to the tumor tissue through the electrodes. And the temperature of the tumor tissue is increased to $42^{\circ}C$ or more to cause thermal necrosis. A mathematical model can be derived a human body model for absorption and transmission of electromagnetic energy in the human model and It is possible to evaluate the distribution of temperature fields in biological tissues. In this paper, we build the human model based on the adult standard model of the geometric shape of the 3D model and use the FVM code. It is assumed that Joule heat is supplied to the anatomical model to simulate the magnetic field induced by the external electrode and the temperature distribution was analyzed for 0-1,200 seconds. As a result of the simulation, it was confirmed that the transferred energy progressively penetrates from the edge of the electrode to the pulmonary tumors and from the skin surface to the subcutaneous layer.