• 플랜트 저널
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• 제10권3호
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• pp.34-38
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• 2014

국내외의 석탄발전기는 주로 기동용 연료로 유류를 사용하고 있으나, 최근 저렴한 석탄을 플라즈마 장치를 이용하여 연소시키는 플라즈마 버너가 도입되어 기동비용을 절감하고 있다. 하지만 플라즈마 버너 초기 운전 시 미연탄소분 증가가 여전히 현안사항으로 남아있으며 기동 시 플라즈마 버너 연소 시의 미연탄소분 저감을 위한 연구와 운전기준 정립이 되어있지 않은 실정이다. 따라서 본 연구에서는 플라즈마 버너의 아크전류에 따른 미연탄소분 영향을 분석함으로써 운전기준을 제시하고자 한다. 또한 석탄발전기 시운전 시 플라즈마 버너의 경제성을 실증함으로써 국내 플랜트 산업에 기여하고자 한다.

• Journal of Welding and Joining
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• 제34권3호
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• pp.40-46
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• 2016

The digital controlled SMA welding power source having the hot start current and short circuit waveform control was developed. The inverter power controller was used an analog circuit and the short circuit waveform controller was developed using a 8-bit MCU. For the evaluation of the developed SMA welding power source it were compared with a domestic welding power sources. Using the high titanium oxide type and low hydrogen type electrodes, the characteristics of hot start and short circuit was evaluated. Developed SMA welding power source shows good start performance. Also, arc stability and low current weldability were improved by the short circuit waveform control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.86-88
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• 2005

The line-start permanent magnet synchronous motor has a high efficiency and an advantage in constant speed operation regardless of the effect of load variation. However it is difficult to predict the performance of characteristics accurately, because of the unbalanced starting torque with the initial starting position of the rotor and the generation of a break torque. In this paper the dynamic characteristics of the line-start permanent magnet synchronous motor arc described and compared with those of the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bars in the line-start permanent magnet synchronous motor.

• Journal of Welding and Joining
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• 제23권5호
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• pp.14-19
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• 2005

In high speed $CO_2$ welding, it has been blown to produce no sound bead with undercut or humping bead. In this study welding phenomena through synchronized high speed camera and output welding voltage and current waveform has been analyzed. For the purpose to improve a welding bead, effect of short circuit current rise slope has been examined. With commercial power source it was produced no sound bead by instantaneous short circuit, long arc period and stubbing at welding speed 2.5mm/min Humping bead or undercut were showed by instantaneous short circuit and long arc period. Also, the weld bead was not formed during the long short circuit period after stubbing start and long arc extinguishment period after wire sticking by failure of arc regeneration, because the droplet was not transferred to weld pool. With increasing short circuit current rise slope the frequency of stubbing was decreased and the normal short circuit rate was increased. A control of short circuit current rise slope was effective factor in high speed welding.

• Journal of Welding and Joining
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• 제13권3호
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• pp.116-124
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• 1995

This paper presents an analytical solution to predict the transient temperature distribution in fillet arc welding including the effect of molten metal. The solution is obtained by solving a transient three-dimensional heat conduction equation with convection boundary conditions on the surfaces of a plate, and mapping the infinite plate onto the fillet weld geometry with energy equation. The electric heat input on the fillet weld and on the infinite plate is assumed to have a combination of two bivariate Gaussian distribution. To check the validity of the solution. FCA welding experiments were performed under various welding conditions. The actual isotherms of the weldment cross-sections at various distances from the arc start point are compared with those of simulation result.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2000년도 특별강연 및 추계학술발표대회 개요집
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• pp.46-49
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• 2000

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.54-56
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• 2004

확실한 아크개시는 자동화 GMAW공정에서 매우 중요하다. 자동차 조립산업 및 부품사업 분야의 아크용접 현장에서는 대부분 박판에 짧은 비드로 용접하는 경우가 많기 때문에 아크개시가 더욱 중요시된다. (중략)

• Journal of Welding and Joining
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• 제13권2호
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• pp.68-81
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• 1995

This paper presents an analytical solution to predict the transient temperature distribution in fillet arc welding. The analytical solution is obtained by solving a transient three -dimensional heat conduction equation with convection boundary conditions on the surfaces of an infinite plate with finite thicknesses, and mapping an infinite plate onto the fillet weld geometry with energy equation. The electric arc heat input on fillet weld and on infinite plate is assumed to have a traveling bivariate Gaussian distribution. To check the validity of the solution, GTA and FCA welding experiments were performed under various welding conditions. The actual isotherms of the weldment cross - sections at various distances from the arc start point are compared with those of simulation result. As the result shows a satisfactory accuracy, this analytical solution can be used to predict the transient temperature distribution in the fiIIet weld of finite thickness under a moving bivariate Gaussian distributed heat source. The simplicity and short calculation time of the analytical solution provides rationales to use the analytical solution for modeling the welding control systems or for an optimization tool of welding process parameters.

• 제어로봇시스템학회논문지
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• 제20권10호
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• pp.1051-1056
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• 2014

In this paper, we introduce an intelligent robotic arc welding system which exploits sensors like as LVS (Laser Vision Sensor), Hall effect sensor, voltmeter and so on. The use of industrial robot is saturated because of its own limitation, and one of the major limitations is that industrial robot cannot recognize the environment. Lately, sensor-based environmental awareness research of the industrial robot is performed actively to overcome such limitation, and it can expand application field and improve productivity. We classify the sensor-based intelligent arc welding robot system by the goal and the sensing data. The goals can be categorized into detection of a welding start point, tracking of a welding line and correction of a torch deformation. The Sensing data can be categorized into welding data (i.e. current, voltage and short circuit detection) and displacement data (i.e. distance, position). This paper covers not only the explanation of the each category but also its advantage and limitation.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.9-15
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• 2004

메탈핼라이드 램프의 가장 큰 단점중 하나는 아크튜브가 뜨거운 상태에서는 순시 재점등이 불가능하다는 것이다. 메탈핼라이드 램프의 점등중 고온의 아크튜브는 초기 램프가 차가운 상태에서의 방전 전압보다 재점등 방전전압이 높아 재점등 시키는데 압력과 온도가 감소되어지는 약5분정도의 시간이 소요 된다. 만약 램프가 뜨거운 상태에서 재점등시키려면 램프전극 양단에 약20[kV] 이상의 높은 전압펄스를 공급해야한다. 따라서 이러한 목적의 전자식 안정기는 EMII필터, PFC회로, 플라이백 컨버터, 하프브리지 인버터, 고전압 이그나이터 회로로 구성되는데 이것은 순시점등은 물론 램프가 뜨거운 상태에서도 20[kV]의 전압으로 램프를 점등/재점등 할 수 있다.