• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.61-63
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• 1999

This paper presents an efficient method for analysis of magnetodynamic system using frequency-dependent parameters. In equivalent electric circuit of linear magnetodynamic system, parameters of inductance and resistance are not constant since they vary with its driving frequency. Once frequency-dependent parameters of equivalent electric circuit for a given system are extracted, they can be used to analyze various characteristics of system. We use the Fourier transform, the high-order sensitivity method and Taylor series in order to efficiently extract the frequency-dependent parameters of magnetodynamic system. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.64-66
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• 1998

This paper presents a new efficient method for transient analysis in magnetodynamic systems of linear eddy current problems. This mehtod employs the Fourier transform and the high-order frequency sensitivity of harmonic finite element method. By taking into account the time-constant of magnetodynamic system, the Fourier integral of continuous frequency is converted into the Fourier series of discrete frequency. And with the results of Fourier series expansion of converted input wave form, the responses of each sinusoids is superposed to give the total response of the magnetodynamic systems. But, if the frequency band of input wave form is broad, it takes long computational time since all responses for each sinusoids must be calculated. Therefore, the high-order frequency sensitivity method is employed to estimate the response variation to frequency. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.60-60
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• 2001

We have investigated the effect of environmental acidity on the induction of apoptosis caused by heat and carboplatin alone or combined. The degree of apoptosis after heating at 42.5$^{\circ}C$ for 1h in pH 6.6 medium was greater than that in pH 7.5 medium in WERI human retinobalstoma cells. When heated in the same pH medium, more apoptosis occurred in the WERI cells than in the Y79 human retinoblastoma cells.(omitted)

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1901-1907
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• 2018

This paper is a study for accurate iron loss calculation of a cylindrical linear machine for free piston engine. This study presents that it is possible to accurately predict power loss in ferromagnetic laminations under magnetic flux by specially considering the dependence of hysteresis, classical, and excess loss components on the magnetic induction derivative. Significant iron loss in the armature core will not only compromise the machine efficiency, but may also result in excessive heating, which could lead to irreversible deterioration in the machine performance. Thus, correct prediction of power losses under a distorted flux waveform is therefore an important prerequisite to machine design, particularly when dealing with large apparatus where stringent efficiency standards are required. Finally, it will be discussed about the iron loss in various materials of cylindrical linear electric machine by geometric and electrical parameters. It will give elaborate information about the perfect design and design rules of cylindrical linear machine and in parallel tools for the calculation, simulation and design will be available.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.153-157
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• 2002

Electricity living body formation operation appliance is using most imports until present. And, because electricity living body formation operation appliance is too expensive, it becomes burden to buy in small scale hospital. Also, problem that economical damage by income is added follows, Therefore, this treatise developed electricity living body formation operation appliance by home production, Ultra high frequency eruption circuit used LC circuit, and output frequency is possible to 8 [MHz], and output voltage amplified maximum 800 [V]. This operation appliance could display size of fixed current. This developed product could microscopic operation fewer than 1 [mm]. This development technology is considered by do metallic surface heat treatment, melting, welding, induction heating device and that can apply to domestic animals surgical operation and so on.

• Journal of Power Electronics
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• v.12 no.6
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• pp.974-981
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• 2012

A FPGA based delta modulated single phase matrix converter has been developed that may be used in both cyclo-converters and cyclo-inverters. This converter is ideal for variable speed electrical drives, induction heating, fluorescent lighting, ballasts and high frequency power supplies. The peripheral input-output and FPGA interfacing have been developed through Xilinx 9.2i, to generate delta modulated trigger pulses for the converter. The controller has been relieved of the time consuming computational task of PWM signal generation by implementing the method of trigger pulse generation in a FPGA by using Hardware Description Language VHDL in Xilinx. The trigger circuit has been tested qualitatively by observing various waveforms on an oscilloscope. The operation of the proposed system has been found to be satisfactory.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.345-346
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• 2017

유도가열은 전자기 유도현상을 이용하여 금속체를 직접 가열하는 방식이므로 높은 변환 효율로 전기에너지를 열에너지로 변환시킬 수 있다. 현재 널리 사용되고 있는 단조용 유도 가열 전원 장치는 주로 위상제어 정류기를 이용한다. 하지만 입력단의 저 역률 및 입력전류 THD가 높은 단점을 가진다. 따라서 본 논문에서는 이러한 단점을 보안하기 위한 3상 다이오드 정류기와 벅 컨버터를 사용한 고 역률 유도가열 전원 장치를 제안한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.127-132
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• 2002

Electricity living body formation operation appliance is using most imports until present. And, because electricity living body formation operation appliance is too expensive, it becomes burden to buy in small scale hospital. Also, problem that economical damage by income is added follows. Therefore, this treatise developed electricity living body formation operation appliance by home production. Ultra high frequency eruption circuit used LC circuit. and output frequency is possible to 8 [MHz], and output voltage amplified maximum 800 [V]. This operation appliance could display size of fixed current. This developed product could microscopic operation fewer than 1 [mm]. This development technology is considered by do metallic surface heat treatment, melting, welding, induction heating device and that can apply to domestic animals surgical operation and so on.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1683-1684
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• 2006

본 논문에서는 Half Bridge Series Resonant Inverter 를 이용한 유도가열 시스템 설계를 하고 제작하여 구현하였다. 이러한 유도가열 시스템의 제작을 위해서는 공진탱크와 매칭 트랜스포머의 설계가 필수적이다. 따라서 이런 설계를 위해 PSpice를 이용하여 공진탱크의 입력 임피던스 Bode Plot 을 그려 분석하고 이를 바탕으로 탱크회로를 설계 하였다. 매칭 트랜스포머의 설계는 출력 Power 와 1,2 차 회로 조건에 의해 설계 되어졌다. 이렇게 설계한 유도가열 시스템을 PSpice를 이용해서 Simulation 함으로써 주파수에 따른 출력 Power 의 변화를 볼 수 있었으며, 유도가열 시스템을 실제 제작하여 구현함으로써 확인하였다.

• Proceedings of the KIEE Conference
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• summer
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• pp.1148-1150
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• 2004

본 논문에서는 $400^{\circ}C$ 이상의 과열 증기발생을 위하여 6kW급 유도가열장치를 개발하여 식품건조 시스템에 적용한 예를 보인다. 유도가열장치는 과열 증기의 온도를 제어하기 위하여 인버터 입력 전압을 $100\sim200V$로 가변제어가 가능하게 하였고, 인버터 입력 전압은 벅컨버터를 사용하여 기준 전압을 과열증기의 온도에 대한 전압 값을 사용하여 제어하였으며, LC 공진에 의해 발생한 전류로 증기 가열 챔버를 유도 가열하여 과열 증기를 발생하게 하였다. 발생한 과열 증기는 식품 건조를 위하여 건조로에 투입되어 고온 건조에서 식품의 건조시간을 단축시킬 수 있었으며, 식품의 손상을 줄일 수 있었다. 이의 검증을 위하여 유도 가열 장치를 설계/제작하여 실험하였으며, 식품 건조 테스트를 행하였다.