• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.4
• /
• pp.517-522
• /
• 2013

The spurious electromagnetic radiation is generated due to the RF unbalanced current on a conductive cable connecting an electronic device to another. A metamaterial-based filtering geometry with frequency selectivity is suggested to reduce the radiation with a bandgap structure, where the right-handed inductance and capacitance stem from the transmission-like configuration between the cable and the metal protrusion, and the left-handed components come from the narrow cavities. The effect of the structure on the unbalanced current pulse and its spurious radiation is presented in the FDTD-method frame work.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.6
• /
• pp.1111-1116
• /
• 2007

Antennas of the near field detection radar require little distortion in time domain caused by multi reflections between feed and open ends of the antenna, so that help to discriminate the target signal from the clutters. The resistive loading techniques have been used to reduce the late time distortions in order to prevent masking of target. In this paper, we design a microstrip antenna with two arms having sloted lines, which have inductance loading effect. Implemented antenna shows better performance on reducing late-time ringing, and the peak value of the received signal becomes 45% greater than the one by the antenna with two non-sloted lines.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.486-488
• /
• 1996

A dc-dc converter which transfers l2-48W of power(regulated output voltage 24V) across a large, variable air gap(1-2cm) has been designed. This converter employs double resonance to compensate the large leakage inductance of the primary and secondary of the transcutaneous transformer. To maximize the effect of resonance, a constant frequency, duty cycle control method is used. The duty cycle control presents advantages over a frequency control in terms of increase in dc voltage gain and reduction of the primary current. The analysis and design procedure for the proposed scheme is presented and the performance result is simulated and verified experimentally.

• Proceedings of the KIEE Conference
• /
• 2003.10b
• /
• pp.193-196
• /
• 2003

This paper describes a micro DC-DC converter using LTCC(Low Temperature Cofired Ceramics) technology. We have designed a inductor, an embedded structure to maximize the effect of miniaturizing, and applied the Neumann's formula to calculate inductance. Also, we have implemented a micro DC-DC conveter of which whole volume is $13{\times}18{\times}0.13[mm^3]$ by embeding other passive components such as resistors and capacitors.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.51-54
• /
• 1991

The effect of inductance for optimal design of Hybrid permanent magnet step motor is presented on this paper. A pull-out torque of Hybrid permanent magnet step motor is measured and calculated by varying stator coil inductances, and power consumption of the step motor also is calculated and compared to the measured value. The relation of developed torque to parer consumption by the changing of magnetomotive force magnitude in a rotor permanent magnet is studied, which is the essence of the step motor design.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.3
• /
• pp.519-523
• /
• 2007

In this paper, we propose a precise parameter extraction of interior permanent magnet (IPM) motors based on finite element analysis. For the calculation of the two-axis inductances Ld and Lq, the slotting effect and cross magnetization due to torque angle are considered. It is examined that back electro-motive force (BEMF) constant is affected by the magnetic saturation in different ways dependent on motor types. Numerical analyses and some measurements are performed for a spoke type and a flux barrier type IPM motors

• Journal of Electrical Engineering and Technology
• /
• v.13 no.6
• /
• pp.2254-2261
• /
• 2018

This paper analyzes stability of current control in respect of four cases of battery energy storage system (BESS) in a stand-alone microgrid. The stand-alone microgrid is composed of BESS, diesel generator and controllable loads, where all of them have a rated power of 50kW. The four cases are considered as following: 1) BESS with a stiff grid 2) BESS with the diesel generator 3) BESS with passive damping + diesel generator 4) BESS with active damping + diesel generator, and their stabilities are analyzed in the frequency domain and discrete time domain. The comparative analysis for four cases are verified through simulation and experiments through demonstration site of the stand-alone microgrid, where the DC link is connected to a 115kW battery bank composed of 48 lead-acid batteries (400AH/12V). Experimental results show a good agreement with the analysis.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.53 no.10
• /
• pp.585-596
• /
• 2004

In this paper, finite element analysis for a PMASynRM is presented and the characteristic analysis of inductance and torque is performed under the effect of saturation. The focus of this paper is characteristic analysis of d and q-axis inductances and torque according to magnetizing quantity of interior permanent magnet for PMASynRM. The d and q-axis current component ratios, load angles of a PMASynRM are investigated quantitatively on the basis of the proposed analysis method and the experimental test. Comparisons are given with output characteristic curves of normal SynRM and those according to the load in PMASynRM, respectively And it is confirmed that the proposed model results in high output power performance.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.880-882
• /
• 2001

A moving-coil-type linear oscillatory actuator is consisted of the NdFeB permanent magnets with high specific energy as the stator, a coil-wrapped nonmagnetic hollow rectangular structure and an iron core as a pathway for magnetic flux. The inductance of moving coil and the push/pull effect is obtained from the permeance model of LOA with the open magnetic circuit. The analytical method are verified using the 2D finite element method.

• Proceedings of the KIPE Conference
• /
• 2012.11a
• /
• pp.153-154
• /
• 2012

여러 개의 셀을 직렬 연결하여 사용하는 대용량 리튬-이온 배터리 사용이 많아지면서 각 셀 간의 전압 평형문제가 중요해지고 있다. 직렬 연결된 각 셀들의 전압이 평형을 이루지 않게되면 그 배터리의 용량을 충분히 활용하지 못하게 되고 배터리 수명 또한 줄게 된다. 셀들 간의 전압 불균형을 바로 잡기 위해선 별도의 셀 전압 균등화 회로가 필요 하다. 본 논문에서는 플라이백 다권선 변압기를 이용한 셀 균등화 회로에서 2차측의 누설 인덕턴스에 의해 생길 수 있는 출력 전압의 차이를 LC필터를 통해 보상하여 셀을 일정한 전압으로 평형을 이룰 수 있도록 하는 회로를 제안하고 시뮬레이션을 통하여 그 타당성을 검증 한다.