• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.131-136
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• 2015

In this paper, prior to the flight model X-band dual-mode circular cavity filter required for the high power transmission of the observation payload in the geostationary satellite, the development model are designed and analyzed to show the analytical multipactor requirement margin. First of all, the multipaction breakdown power sensitivities were analyzed by changing the iris width and thickness within the filter, and through that the iris width and thickness was selected and then the multipaction threshold powers over the frequencies within the bandwidth were analyzed and the required margin of 8 dB was obtained. Also for the high power transmission filter, another important phenomena known as corona breakdown are analyzed for the iris width and thickness changes. Finally the development model manufactured was tested and the results met the key requirements.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.981-982
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• 2011

This paper discusses design aspects of slotless permanent magnet generator for high performance and low speed applications. The airgap flux density in was obtained from finite element analysis and the design of a PM generator. The relatively large diameter stator laminations of such machines tend, therefore, to have a very thin back of core and narrow teeth, which make them expensive and difficult to manufacture. this thesis proposes an alternative PM generator topology featuring a slotless stator whose laminations are manufactured from a split core. The test results with a resistive load confirm the satisfactory operation of generator.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.53-55
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• 2008

In high speed applications, the slotless permanent magnet(PM) motors appear an attractive solution, being almost insensitive to magneto-motive force harmonics and to pulse width modulation(PWM) current ripple and exhibiting lower stator iron losses and rotor losses (significant with square wave current control). So, this paper deals with methods for design of permanent magnet synchronous motor/generator.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.793-794
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• 2006

본 논문은 Slotless BLDC 모터를 고출력화 하기 위해서 나선형(Helical)방식을 적용하여 모터의 고출력화를 이루는 방식에 대한 연구이다. 기존의 SlotlessBLDC모터는 코깅이 없고, Slot이 없으므로 소형화에 유리한 장점을 지녔다. 반면에 공극의 자속 밀도가 낮아 출력을 높이는데 한계가 있었다. 따라서 본 논문에서는 기존의 SLBLDCM의 단점을 극복할 수 있는 Helical 방식을 제안하였다. Helical 방식을 적용할 때 기존의 인덕턴스 영향으로 인한 전류 확립에 한계가 있었으나 본 방식을 적용 시 높은 전류를 흘릴 수 있었으며 이로 인해 고출력화를 이룰 수 있었다. 아울러 Helical 방식을 취하므로 높은 전류로 인한 발열문제까지도 동시에 해결할 수 있는 장점이 있었다. 본 논문에서는 Helical 방식을 적용하여 기존대비 출력을 15%이상 향상시킬 수 있었으며, 온도 상승도 10%이상 억제할 수 있었다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.747-749
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• 2000

This study deals with the characteristic analysis of slotless PMLSM based on the analytical method. Slotless PMLSM produces the thrust ripples due to the harmonic component of back-EMF. Therefore, this paper presents the thrust ripple minimization technique, by modifying the pole ratio and the coil width. The results of the proposed mehtod are compared the ones of FEM.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1057-1059
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• 2003

This paper presents drive analysis of slotless air-cored PM linear synchronous motor using two-dimensional analytical method. In order to calculate dynamic characteristic, back-EMF and linkage flux are calculated by Permanent Magnet Field and also inductance are given by slotless winding current coil. PMLSM drive simulation is performed by PI control system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1039-1046
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• 2007

This paper presents the analysis for power consumption, mechanical vibration and acoustic noise characteristics of the Coreless and Slotless Brushless DC motor in Digital Lightening Processor(DLP) Motor with the Air-Dynamic Bearing. The Coreless BLDC motor has not the stator yoke as well as the stator slot to remove the unbalance force by the interaction between the stator yoke and Air-Dynamic Bearing clearance. The assembling tolerance and the processing error make the air-gap difference between the magnet and the stator yoke .which occurs the unbalanced electro-magnetic force in the Slotless BLDC motor. It imposes the air-dynamic bearing on the disturbance force and makes the Air-Dynamic Bearing vibrated and noised. Also, The attractive force between the magnet and the silicon steel stator yoke increases the power consumption. In this paper, the power consumption, mechanical vibration and acoustic noise of the Coreless BLDC motor and the Slotless BLDC motor with the silicon steel stator yoke are simulated, analyzed, and tested using the manufactured proto-type motors with Air-Dynamic bearing. The simulated and tested results present that the Coreless BLDC motor without the silicon steel stator yoke has the lower mechanical vibration and noise ,and lower power consumption than the Slotless BLDC motor with the silicon steel stator yoke in Digital Lightening Processor Motor with Air-Dynamic Bearing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1639-1647
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• 2016

This paper deals with eddy current loss analysis of Slotless Double sided Cored type permanent magnet linear generator by using analytical method, space harmonic method. In order to calculate eddy current, this paper derives analytical solution by the Maxwell equation, magnetic vector potential, Faraday's law and a two-dimensional(2-D) cartesian coordinate system. First, we derived the armature reaction field distribution produced by armature wingding current. Second, by using derived armature reaction field solution, the analytical solution for eddy current density distribution are also obtained. Finally, the analytical solution for eddy current loss induced in permanent magnets(PMs) are derived by using equivalent, electrical resistance calculated from PMs volume and eddy current density distribution solution. The analytical result from space harmonic method are validated extensively by comparing with finite element method(FEM).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2135-2144
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• 2007

This paper presents system design of the slotless double-side Permanent Magnet Linear Synchronous Machine system (PMLSM) through magnetic field analysis and dynamic modeling. In our analysis, 2-D analytical treatments based on the magnetic vector potential were adopted to predict magnetic field with space harmonics by PM mover magnetization and stator winding current. From these, the design parameters such as inductance, Back-emf, and thrust are estimated. And, the electrical dynamic modeling including synchronous speed is completed by calculation of a DC link voltage in effort to obtain the accurate mechanical power from Space Vector Pulse Width Modulation(SVPWM). Therefore, the system design of PMLSM is performed from estimation of design parameters according to PM size and coil turns in magnetic field and from calculation of a DC link voltage to satisfy base speed and base thrust represented as the maximum output power in dynamic modeling. The estimated values from the analysis are verified by the finite element method and experimental results.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.707-708
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• 2008

본 논문에서는 초전도 플라이휠 에너지 저장장치 (Superconductor Flywheel Energy Storage System : SFES)의 에너지 변환을 위해 사용된 영구 자석형 전동 발전기(Permanent Magnet Synchronous Motor/Generator : PMSM/G)가 SFES의 에너지 저장효율에 미치는 영향을 평가하였다. SFES 시스템은 YBCO 벌크 초전도체를 이용한 저어널 타입(journal type)의 초전도 베어링을 사용하였으며, 슬롯리스 형 PMSM/G를 사용하였다. PMSM/G의 고정자 코어, 누설 자속 및 감겨진 코일에 의한 저장 에너지 손실을 측정하였다. 사용된 코어의 크기, 누설자속, 및 코일의 적절한 선정을 통하여 저장된 에너지의 손실을 상당히 줄일 수 있음을 확인하였다. 또한 영구자석과 코어가 동시에 회전하는 회전 코어형 전동발전기를 적용하여 에너지 손실을 매우 감소시킬 수 있음을 확인하였다.