• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.209-212
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• 2003

The superconducting generator and motor have many advantages over the conventional machines. The better characteristics originates from the higher magnetic field density by way of superconducting field coil which conducts the operating current with very large density. The major merits of the superconducting machines can be explained as the smaller size and weight as well as the higher efficiency. The compactness would be very useful for the applications such as ship propulsion motors and the higher efficiency is expected to play a good role in saving the electricity generation cost for the generators used in power plants. In spite of these advantages the main reason for the lazy commercialization is known as the expensiveness of the superconductors and the cryogenic systems. In this paper focusing on the superconducting generator, we will consider and estimate the economic effectiveness when the machines permeate into the actual AC generator market in Korea gradually.

• 한국초전도ㆍ저온공학회논문지
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• 제4권2호
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• pp.31-37
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• 2002

A 100 〔HP〕 rated synchronous motor with superconducting rotating field winding has been designed based on the formulated equations established from 2 dimensional magnetic field distributions in a cylindrical coordinate The cross-section was drawn based on calculated design results via Fortran program and then modeled with FEM (Finite Element Method) to investigate the machine performances. First of all, the magnetic field distributions are analysed in many ways according to the field directions and the armature currents. Especially after the rotating Held winding is arranged with BSCCO-2223 high-temperature superconducting(HTS) pancake coils, the exerted magnetic field normally on the HTS tape is calculated through FEM. And the machine output power is calculated according to the torque ang1es which lie between the field and the armature main flux lines. Moreover, this Paper includes the eddy-current loss variations of a copper damper located between the field and the armature coils and design considerations of the 100 HP HTS motor utilizing ferro-magnetic material.

• 한국정밀공학회지
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• 제16권9호
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• pp.104-109
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• 1999

The flywheel energy storage system using superconducting magnetic bearings is a device to store electrical energy as rotatioal kinetic energy by motor and to convert it to electrical energy by generator when it is necessary. The rotordynamic analysis should be performed with an adequate analytical model and equations of motion to identify the stable driving condition and the dynamic behavior. The critical speed and the unbalance response of superconducting magnetic bearings-flywheel system are studied in this paper. The analytical results show that the system has one forward whirling mode and two backward whirling models below 500rpm. The maximum displacement 0.75mm is detected at the first forward mode (385rpm)through unbalance response analysis. The analytical results are compared with the experimental result by the spin-down test. The experimental result shows that the maximum displacement is 0.7mm at 370rpm.

• 한국전자통신학회논문지
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• 제10권7호
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• pp.775-780
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• 2015

초전도 현상은 절대온도 부근에서 전기적 저항이 사라지고 자기부양 효과를 보이는 등의 장점 때문에 다양한 분야에서 적용이 시도되고 있지만 초전도 임계온도를 실현하기 위한 어려움 때문에 실용화에 많은 어려움을 겪어 왔다. 하지만 최근 $30^{\circ}K$ 이상에서 초전도 현상을 보이는 고온 초전도체가 발견됨으로서 다양한 분야에 대한 적용연구가 시도되고 있다. 따라서 본 논문에서는 최근 각광받고 있는 고온 초전도체의 전력계통 적용 사례들은 조사, 분석하여 그 가능성과 문제점들을 살펴보고자 한다.

• 한국초전도ㆍ저온공학회논문지
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• 제2권2호
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• pp.44-48
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• 2000

The high temperature superconducting bulk can be used as the rotor of an ac motor. This paper presents the fabrication and test results of a ac motor with HTS bulk rotor. The rotor of a conventional squirrel cage induction motor was replaced with cylinder type YBCO bulk. Height and outer diameter of the HTS bulk was 15mm and 46mm, respectively. Eddy current brake using aluminium disk was used to measure the torque of the HTS motor. No load test, locked rotor test and load test were performed to examine the characteristics of the HTS motor. Test results show the motor can rotate at synchronous speed without any special starting circuit. Maximum output power of the constructed HTS motor was 408W.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권9호
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• pp.442-447
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• 2003

Motors with HTS wires or bulks have been developing recently. Those are large synchronous motor with HTS wires at the field winding in the rotor, hysteresis and reluctance motors with HTS bulk in the rotor. This paper presents the fabrication and test results of an HTS induction motor. Conventional end rings and short bars were replaced with HTS wires in the motor. Stator of the conventional induction motor was used as the stator of the HTS motor. Rated capacity and rpm at full rotor of the conventional motor were 0.75[kW] and 1,710[rpm]. Two, HTS wires are used in parallel to make the end rings and bars. The critical current of the BSCCO-2223 HTS wire which was used in the bars and end rings were 115[A]. Electrodynamometer was coupled directly to the shaft of the rotor with HTS wires.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2000년도 KIASC Conference 2000 / 2000년도 학술대회 논문집
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• pp.73-76
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• 2000

Superconductivity is key technology for 21st century. To suppress emission of green house effect gas, applied superconductivity is important. In this paper, the current status of superconducting power machines such as generatorand motor are described. Most of all studies are the step of demonstration of idea and possibility. There are large gap between physical idea and actual apparatus. Further collaboration between scientists and engineers has been required.

• 한국초전도ㆍ저온공학회논문지
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• 제11권2호
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• pp.33-36
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• 2009

A 1 MW class HTS (High-Temperature Superconducting) synchronous motor has been developed. This motor is aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field coil of the developed motor is cooled by way of neon thermo siphonmechanism and the stator (armature) coil is cooled by water through hollow copper conductor. This paper also describes evaluation of some electrical parameters from performance test results of our motor, which was conducted at steady state in generator mode and motor mode. Open and short circuit tests were conducted in generator mode while a 1.1 MW rated induction machine was rotating the HTS machine. Electrical parameters such as mutual inductance and synchronous inductance are deduced from these tests. Load test was done upto rating torque during motor mode and efficiency was measured at each load torque.

• 한국초전도ㆍ저온공학회논문지
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• 제10권1호
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• pp.57-61
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• 2008

A 1MW class HTS(High-Temperature Superconducting) synchronous motor has been developed. This motor was aimed to be utilized for industrial application such as large motors operating in large plants. The HTS field windings of the developed motor is cooled by way of Neon thermosiphon mechanism and the stator coil is cooled by water through hollow copper conductor. This paper describes performance test results of our motor, which was conducted at steady state in generator mode and motor mode.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권2호
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• pp.94-100
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• 2005

Korea Electrotechnology Research Institute(KERI) has successfully developed a 100hp-1800rpm-class high temperature superconducting(HTS) motor with high efficiency under partnership with Doosan Heavy Industries & Construction Co. Ltd. This motor has a HTS field winding and an air-cooled stator. The advantages of HTS motor can be represented by a reduction of 50% in both losses and size compared to conventional motors of the same rating. The cooling system is based on the heat transfer mechanism of the thermosyphon by using GM cryocooler as cooling source. The cold head is in contact with the condenser of a Ne-filled thermosyphon. Independently, the rotor assembly was tested at the stationary state and combined with stator. The HTS field winding could be cooled into below 30K. Test of open-circuit characteristics(OCC) and short-circuit characteristics(SCC) and load test with resistive load bank were conducted in generator mode. Also, load tests in motor mode driven by inverter were finished at KERI. Maximum operating current of field winding at 30K was 120A. From OCC and SCC test results synchronous inductance and synchronous reactance were 2.4mH, 0.49pu, respectively. Efficiency of this HTS machine was 93.3% in full load(100hp) test. This paper will present design, construction. and experimental test results of the 100hp HTS machine.