• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.748-757
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• 2007

This paper is intended to solve the technical problem that fails in large-capacity induction motor starting due to serious voltage drop during starting period. One induction motor that is established already can reach in steady-state using reactor starting method but the voltage magnitude of PCC (point of common coupling) has dropped down a little. When the same capacity induction motor is installed additionally in the PCC, where the existing induction motor is operating, voltage drop becomes more serious by starting of additional induction motor. As a result, the additional induction motor fails in starting. Therefore, voltage compensation method is proposed so that all of two induction motors can be started completely. First, modeling technique is described in order to implement starting characteristics of large induction motor. And then, this paper proposes strategic starting scheme by proper voltage compensation that use no-load transformer tap control (NLTC) and step voltage regulator (SVR) for starting of two large induction motors successfully and improving the feeding network voltage profile during the starting period. The induction motor discussed in this paper is the pumped induction motor of 2500kVA capacity that is operating by KOWACO (Korea Water Resources Corporation). Modeling and simulation is conducted using PSCAD/EMTDC software.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.224-227
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• 2003

Single phase induction motor(SPIM) is one of the most widely used type of low power AC motors in the world, especially for domestic or commercial applications where a three phase power supply is not available. Fractional horse power of the SPIM have no starting torque their own. So there are several ways of starting SPIMS. The most common type is the starting capacitor installed in series with the auxiliary winding to increase the starting torque. Also, the auxiliary winding is disconnected once the speed of the motor reaches 70 to 80 [%] of the rated speed. In the conventional systems, this function is conducted by a centrifugal switch. But the mechanical centrifugal switch has many problems such as switch malfunction. This paper presents the starter design of SPIM capacitor starting switch using microcontroller.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.105_106
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• 2009

본 논문은 가압펌프용 전동기에 대한 기동방법을 정류소자(Soft starter)에 의한 기동전류 제어방식을 채택하고 있는 수도사업장에서 한전 수전에 의한 펌프모터 기동시에는 원활하게 운전이 가능하였으나 비상용 디젤발전기 부하운전에서 펌프모터를 기동하는데 실패함에 따라 상이한 전력공급계통으로부터 펌프모터 기동시 콘덴서의 특이현상과 고조파의 영향에 따른 모터 기동특성을 비교분석한 사례를 중심으로 연구되었다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.6
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• pp.294-300
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• 1999

There is a growing interest in hybrid electric vehicles due to environmental concerns. Recent efforts are directed toward developing an improved main component systems for the hybrid electric vehicle applications. Soon after the introduction of electric starter for internal combustion engine early this century, despite being energy efficient and nonpolluting, electric vehicle lost the battle completly to internal combustion engine due to its limited range and inferior performance. Hybrid Electric vehicles offer the most promising solutions to reduce the emission of vehicles. This paper describes a method for cost reduction estimation of parallel hybrid electric vehicle. We used a cost reduction structure that consisted of five major subsystems (three-type and two-type motor) for parallel hybrid electric vehicle. Especially, we estimated the potential for cost reductions in parallel hybrid electric vehicle as a function of time using the learning curve. Also, we estimated the potentials of cost by depreciation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.250-250
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• 2004

자동차의 시동을 걸기 위해서는 맨 처음 엔진을 강제로 가동시키는 기계장치가 있어야 하며, 이를 시동모터라 한다. 시동모터는 모터부와 그 부속장치 그리고 발생된 힘을 엔진으로 전달하는 동력전달 기구로 구성되어 있다. 동력전달기구는 플라이 휠이라는 부품을 크랭크 축 끝단에 장착한 후 그 원주상에 링 기어를 만들고, 시동모터의 축에 피니언이라는 작은 기어를 맞물리게 하여 시동 키를 돌리면 이 기어가 회전되는 원리를 이용하고 있다. 피니언 기어는 작고 반대로 플라이 휠에 장착되어 있는 링 기어는 크기 때문에 일정한 기어비가 형성되어 큰 부하의 엔진회전이 가능하다.(중략)

• 전기의세계
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• v.15 no.5
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• pp.32-39
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• 1966

This voltage Regulator, which regulates voltage in different way from the conventional regulator, is constructed by circular-plate core type stators and controllers (are similar to rotor of conventional). The principle of this Voltage Regulator is based on the rotating magnetic field theory including peculiar homopolar and heteropolar concept. Comparing with the conventional induction regulator, this regulator need not to have short windings and can cancel armature reaction. Moreover, it is able to decrease the machine noise and control the phase of it freely. And it's efficiency can become more than 95% which almost the same as that of transformer's. By increasing numbers of cores of the same size, the output power can be increased, the insulation can be decreased and high Voltage can directly be connected because applied voltage is distributed to each core. This Voltage Regulator can be also used as a current regulator, a starter a induction motor and a phase transformer etc.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.37-42
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• 2013

This paper deals with Wound Rotor Synchronous Motor (WRSM) purposely designed for Integrated Starter and Generator (ISG) installed in 42V automotive electrical system. Not only design objective and specifications of WRSM, but its adaptive design to minimize torque ripple and back-EMF Total Harmonics Distortion (THD) are considered. Furthermore, design characteristics of designed prototype have been investigated numerically in terms of torque, back EMF, loss, and efficiency, which are verified by performance comparison with Interior Permanent Magnet Synchronous Machine based on Finite Element Analysis (FEA).

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.3-5
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• 2001

에너지와 환경에 대한 관심이 증대되면서 전동기의 고효율화의 필요성이 증대되고 있다. 현재 유도전동기의 고효율화에 대한 연구가 진행되고 있지만 슬립으로 인한 회전자 동손의 감소는 한계점이 존재한다. 또한 영구자석 동기전동기는 별도의 기동장치가 필요하므로 제품의 단가가 증가하게 된다. 이에 기동은 유도기의 특성을 이용하고 정격시는 동기전동기로 운전하는 영구자석 매입형 유도성 기동전동기의 효용성이 높아지고 있다. 본 논문에서는 유도동기전동기의 과도상태 토크특성 및 동기시의 효율 등을 유한요소법을 이용하여 계산하였다. 본 해석법을 현재 생산중인 섬유기계용 유도동기 전동기에 적용하여 그 특성을 해석하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.182-189
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• 2016

A modeling method of electric power network inside a fishing boat less than 5 tons is proposed for its high-energy efficiency with renewable energy sources. The power network inside the fishing boat consists of a diesel engine, a starter motor, an alternator, battery packs, and electric loads, which are connected in parallel. To obtain proper power network model, the voltage -current characteristics of the electric components are considered to develop elaborate electrical models under several load conditions. Measured data of the battery and alternator current include noise. By using an average method, the AC components from the power network of the fishing boat can be reduced, which is verified by KCL rule. Using the proposed power network model, the power generation of the alternator and the reduction of diesel consumption in the boat's engine are predictable under various operating conditions. The validity of the proposed methodology is verified by comparing simulation results with experimental measurements using statistical inferences.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.37-52
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• 2011

Supply chain management is a strategic thinking which enhances the value of supply chain and adapts more promptly for the changing environment. For the seamless partnership and value creation in supply chains, information and knowledge sharing and proper partner selection criteria must be applied. Thus, the partner selection criteria are critical to maintain product quality and reliability. Each part of a product is supplied by an appropriate supply partner. The criteria for selecting partners are technological capability, quality, price, consistency, etc. In reality, the criteria for partner selection may change according to the characteristics of the components. When the part is a core component, quality factor is the top priority compared to the price. For a standardized component, lower price has a higher priority. Sometimes, unexpected case occurs such as emergency order in which the preference may shift on the top. Thus, SCM partner selection criteria must be determined dynamically according to the characteristics of part and its context. The purpose of this research is to develop an OWL model for the supply chain partnership depending on its context and characteristics of the parts. The uncertainty of variable is tackled through fuzzy logic. The parts with preference of numerical value and context are represented using OWL. Part preference is converted into fuzzy membership function using fuzzy logic. For the ontology reasoning, SWRL (Semantic Web Rule Language) is applied. For the implementation of proposed model, starter motor of an automobile is adopted. After the fuzzy ontology is constructed, the process of selecting preference-based supply partner for each part is presented.