• Journal of the Korean Wood Science and Technology
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• 제28권4호
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• pp.83-93
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• 2000

This study was carried out to improve the physico-mechanical properties of board products by applying the technique of high frequency heating, and find out the optimum conditions of high frequency heating, compared with the technique of hot platen heating. The possibility of isocyanate resin application to board production was also considered to solve the problem of free formaldehyde emission from urea resin which is generally used in wood industry. For this study, 30 mm thick MDP (medium density fiberboard) with isocyanate resin were manufactured by the techniques of hot platen heating, high frequency heating and the combination techniques of both heating methods, and compared in several point of views.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.117-123
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• 2010

제안한 유도가열 시스템은 증류탑 장치에 사용되는 특수적층 규칙충진체에 의한 열 교환기술과 IH(Induction-Heating)전자유도가열용의 특수한 고주파 전력회로 기술을 응용한 차세대 가열방식이다. 본 전자유도 유체가열기술은 IGBT대응의 고주파 인버터를 사용하여 상용교류로부터 수[kHz]의 고주파 교류를 발생시킬 수 있다. 공진형 고주파 인버터를 사용함으로 고성능, 고효율의 시스템화가 가능하다. 본 논문에서는 주파수 범위가 20[kHz]에서 44[kHz]인 고주파 공진형 인버터을 이용하여 증기를 발생시키는 유도가열시스템에 대해 제안한 온도제어에 대하여 기술하고자 한다.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.40-51
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• 2008

This research presents a new active auxiliary resonant snubber with for induction heating PWM high frequency inverter solving the problem of induction heating PWM high frequency inverter circuit which is using widely in the practical application of an induction heating apparatus, the soft switching operation and power control are impossible when the lowest power supply in the active auxiliary resonant snubber with for induction heating PWM high frequency inverter. The inverter circuit which is attempted by the on-off operation of a switch has the effect of reducing the power loss due to soft switching and high frequency switching. This confirms that power regulation is possible on a continuous basis from 0.25[kW] to 2.84[kW] where the duty factor(D) changes from 0.08 to 0.3 under zero current switching which operates by an asymmetrical pulse width modulating control. The power conversion efficiency is 95[%]. Due to these results, the active auxiliary resonant snubber for an induction heating PWM high frequency inverter is considered effective as a source of induction heating.

• 조명전기설비학회논문지
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• 제27권6호
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• pp.68-74
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• 2013

Induction-heated system is innovative system which applied IH(Induction Heating) magnetic induction heating generated from induction-heated metallic package and high-frequency power circuit technique for thermal converse technique. In this occurs not burning, so that the working environment and deterioration of products can be improved. This technique is used high frequency inverter. By using high frequency inverter high frequency in the range of kHz can be made with conventional alternative current. In this contribution IGBT module is used for high frequency inverter. In this paper are discussed analysis of characteristics according to the each frequency and produced Flat plate induction heating system using 1.5kW-class half-bridge resonant inverter. In addition, operating characteristics of the system to changes in the distance between the coil and the heater, applications of system are also discussed.

• 조명전기설비학회논문지
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• 제14권6호
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• pp.12-17
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• 2000

IN induction heating system the high frequency operation allows a rapid response to current fluctuation in the inverter and result in improved welding quality. To work induction heating of nonferrous metals, a welding power supply is need high working frequency and high power. This paper is shown design technique for increasing working frequency in induction heating for welding coppers. A series-parallel resonate inverter consists of H-type bridges, each of whose arms is composed of a combination of two parallel IGBTs. Inverter operating with the fixed frequency is controlled by pulse width modulation (PWM). As switching adapted the Zero-Voltage Switching technique to reduce switching losses the system is high efficiency. The propose inverter has feature which is high efficiency for very wide load variations with a narrow range of duty cycle ratio control and load short circuit capability. Detailed experimental results obtained from a 48[V] output, 500[W] experimental inverter are presented to verify the concept.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.305-309
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• 2008

This paper presents an innovative prototype of a new conceptual electromagnetic induction eddy current based fluid heating appliance using voltage-fed quasi resonant zero voltage soft switching PWM high-frequency inverter using IGBTs, which can operate at a constant frequency variable power regulation scheme. The promising simple high efficient low noise inverter type electromagnetic induction eddy current based pipeline fluid heating appliance is proposed for saturated steam generator, superheated steam generator, hot water and hot air producer, metal catalyst heating for exhaust gas cleaning in engine. Under these technological backgrounds, a novel electromagnetic induction eddy current Dual Packs Heater(DPH) based pipeline fluid heating incorporates thin metal layer type package for continuous fluid heating appliances applying two types of voltage-fed quasi load resonant ZVS-PWM high frequency inverter. The unique features of a novel electromagnetic induction eddy current DPH based continuous pipeline fluid heating appliance is illustrated on the basis of simulation and discussed for the steady state operating characteristics and experimental results.

• 전력전자학회논문지
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• 제10권5호
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• pp.481-487
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• 2005

제안한 유도가열 시스템은 증류탑 장치에 사용되는 특수충진체에 의한 열교환기술과 IH(Induction-Heating)전자유도가열용의 특수한 고주파 전력회로 기술을 응용한 차세대 가열방식이다. 특히 일체의 연소과정이 없다는 점에서 작업환경의 개선이 가능하며 본 기술은 IGBT대응의 고주파 인버터를 사용하여 상용교류로부터 수[kHz]의 고주파 교류를 발생시킬 수 있다. 본 논문에서는 절연체 용기 내에 특수 스텐레스 발열체부하를 수납하여 용기 외부의 고주파 공진형 인버터 접속의 워킹코일로부터 비접촉 상태로 전자유도 와전류를 구조체에 흘림으로서 발열하게 되는 새로운 유체가열방식을 제안한다. 그리고 5[kW]급 풀-브릿지 공진형 인버터 시스템과 공진부하의 동작해석, 특성분석 및 본 시스템을 이용한 고효율 스팀 발생장치의 개발과 시스템의 응용에 대해 논하였다.

• 대한기계학회논문집A
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• 제32권6호
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• pp.533-539
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• 2008

An high frequency induction hardening technology of vehicle body press-formed of thin sheet steel has been developed to increase the strength of vehicle body parts locally by high frequency induction heating, thereby eliminating the need for reinforcements. And this technique for increasing the tensile strength of sheet steel was practically applied to the front floor cross member and center pillar reinforcement of a passenger car. The side impact behavior has been investigated when induction hardening technology is applied to the conventional low-carbon steel and weight reduction of an automotive body is expected. In this paper, basic experiments were performed for the hat-shaped specimen under high frequency induction heating process. Martensitic transformation was found in the heating zone through microscopic observation which showed higher hardness. In addition, the hardness and strength of the center-pillar specimen made of boron steel increased remarkably by high frequency induction heating.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.437-440
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• 2009

High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact manner. Thanks to its capability of rapid heating and cooling of mold surface, it has been recently applied to the injection molding. The present study applies the high-frequency induction heating for elimination of weldlines in an injection-molded plastic part. To eliminate weldlines, the mold temperature of the corresponding weld locations should be maintained higher than the glass transition temperature of the resin material. Through experiments, the maximum temperature of $143^{\circ}C$ is obtained on the mold surface around the elliptic coil, while the temperature of the mold plate is lower than $60^{\circ}C$. An injection molding experiment is then performed with the aid of induction heating, and the effect of induction heating conditions on the surface appearance of the weldline is investigated.

• Journal of Welding and Joining
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• 제33권1호
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• pp.80-86
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• 2015

The purpose of this study is to establish the predictive method of the angular distortion caused by the line heating process with high frequency induction heating. In order to do it, the heat input model for the high frequency induction heating system was established through comparing the temperature evaluation results obtained by both FEA and experiment. The critical heating conditions to prevent the degradation of the work piece with various thicknesses were identified by FEA and microstructure test results. Under the critical heating conditions, the extensive line heating tests were performed. According to the test results, it was found that the angular distortion behavior of the heated plates could be defined as the function of heat intensity and the rigidity of heated plate. In addition, it was clarified that the angular distortion strongly depended on the size of test specimen such as the length and the width of the heated plate. Based on these results, the predictive equation for the angular distortion was established with the function of heat intensity, bending rigidity and size of heated plate.