• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.5
• /
• pp.955-964
• /
• 2011

In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.7
• /
• pp.791-799
• /
• 2008

In this paper, the electromagnetic modeling and network analysis are proposed for design of GTEM cell operating from DC to 18 GHz. 3D electromagnetic numerical analysis models composed of the coaxial mode-converter for the feeder of GTEM cell, 5 m expanded rectangular coaxial transmission line, and the resistive termination load for current and field transmitted from the feeder are developed. Equivalent network model of feeder, transmission line, and termination load in the GTEM cell is also proposed, so the return loss of GTEM cell is calculated using S-parameters using the electromagnetic numerical analysis. To verify the proposed design method, the GTEM cell is designed, constructed and tested, with its size of $5{\times}2.5{\times}1.7\;m$ and operating frequency of $DC{\sim}18\;GHz$.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.520-522
• /
• 2005

This paper presents the design and analysis of the electromagnetic system such as jumping ring system. Also, we study the characteristics of dynamics for system with initial parameter. For the propose of system control,, first, we simulate the MATLAB tool solving coupled differential equations with electric parameter, inductance and mutual inductances. Therefore, we design a jumping ring system using design results, implement, and analyze the jumping ring system real situation. For the near time, we present a control process, and compare of real system and software technique.

• ETRI Journal
• /
• v.40 no.4
• /
• pp.546-553
• /
• 2018

Since the Gyeongju earthquakes in 2016, there have been increased research interests in the areas of seismic design, building collapse, and rescue radar applications in Korea. Ground penetrating radar (GPR) is a nondestructive electromagnetic method that is used for underground surveys. To properly design ground penetrating radar that detects buried victims precisely, it is important to study electromagnetic wave propagation channel characteristics in advance. This work presents an electromagnetic propagation environment analysis of a trapped victim for GPR applications. In this study, we develop a realistic collapse model composed of layered reinforced concrete and a victim positioned horizontally. In addition, the effects of rebars and the distance between the radar antenna and target are investigated. The numerical analysis presents the electromagnetic wave propagation characteristics, including amplitude loss and phase difference, in the 450-MHz and 1,500-MHz frequency band, and it shows the electric field distribution in the environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.5
• /
• pp.839-848
• /
• 2000

This paper presents the results of an electromagnetic field analysis for a reverberation chamber that is an alternative method of a shielded anechoic chamber, which is widely used for the analysis and measurement of electromagnetic interference and immunity test. Inside the defined test volume of the rectangular and triangular type, the Schroeder Quadratic Residue Diffuser was employed. FDTD(Finite-Difference Time-Domain) simulation method was applied to produce the field characteristics inside those reverberation chambers. According to the results, field uniformities on the aforementioned two types of reverberation chambers were correlated within $\pm$3dB, and $\pm$4.4dB tolerances, and rectangular type reverberation chamber shows an independent polarization result.

• Proceedings of the KIEE Conference
• /
• 2007.10c
• /
• pp.118-120
• /
• 2007

This paper deals with the vibration analysis of characteristics for BLDC motor by electromagnetic exciting force. Vibration analysis of electric machine is mainly divided into mechanical and electrical approach. However, it need to execute coupling analysis of mechanical and electrical computation because the vibration sources have relation to each other. Magnetic fields is calculated from Maxwell stress method with electromagnetic finite element method. And magnetic radial force is calculated from previous magnetic fields. With coupled electromagnetic and structure finite element, the vibratory behavior between the phase commutation advancing technique and pulse-width control is investigated in single phase brushless dc motor.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.2
• /
• pp.318-327
• /
• 2010

This paper deals with analysis on dynamic characteristic and circuit parameter of linear switched reluctance motor by electromagnetic analytical method. Above all, using space harmonic method, which is electromagnetic method, the air-gap flux density is analyzed in the both align and unaign positions, and the inductance profile, force characteristic and resistance per phase are calculated by means of the process. The validity of the analyzed results are demonstrated by the finite element method(FEM) and manufacture of the prototype machine. Second, the dynamic simulation is analyzed by the use of circuit parameters derived from analytical method, and the operating system of the prototype machine is manufactured to demonstrated the validity of simulation analysis. As a result, it is considered that the characteristic equation suggested in this paper will contribute to the design, analysis and application of LSRM.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.1020-1023
• /
• 2005

The fluid flow and thermal analysis were carried out by using the finite element program, Ansys. In analysis process, a electromagnetic analysis was accomplished. In afterwards, Fluid and thermal analysis was done. Fluid flow and heat could be produced by electromagnetic pump. In other words, A magnetic field which electromagnetic pump generates influences Liquid Material(Al alloy). This paper calculates the fluid flow and temperature distribution according to time. Using material is Al alloy(A356).

• Journal of electromagnetic engineering and science
• /
• v.6 no.4
• /
• pp.229-234
• /
• 2006

This paper presents an advanced method of simulation for EM(electromagnetic) environment that affects on mobile receivers. A new calibration algorithm in the process of simulation is introduced. With a proposed calibration method, the time required for simulation is reduced and this makes it possible to simulate a near-real time EM environment in a shielded anechoic chamber. EM environment data acquisition and logging techniques with GPS for simulation were developed.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.549-552
• /
• 2003

The electrical current generated by heart creates not only electric potential but also a magnetic field. We have observed electrophysiological phenomena of the heart by measuring tangential components of magnetocardiogram(MCG) using 61 channel superconducting quantum interference device(SQUD) system. In this paper, we developed a new analysis method, which is based on the theory of electromagnetic field. We show some differences of the current direction between the normal MCG and the abnormal(ischemic heart disease) MCG.