• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.28-34
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• 2014

A claw pole stepping motor is widely used in various fields such as a compact optical disk drive, computer peripherals, digital cameras, office automation(OA), handheld mobile devices, because it has the suitable structure for compact motor. However 3D analysis is essential for design of Claw pole stepping motor because of axial flux path. Thus, in general, it takes a lot of time in the design of Claw pole motor. In this paper, magnetic equivalent circuit considering axial flux was proposed to reduce design time of Claw pole motor and we has designed by using the magnetic equivalent circuit. In addition, in oder to verify the study, design model was verified by 3D FEM simulation and experiment.

• Journal of electromagnetic engineering and science
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• v.13 no.2
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• pp.134-136
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• 2013

This paper examines various aspects of the electromagnetic responses of the ring resonator located in the transverse electromagnetic cell. In addition, an equivalent circuit for the ring resonator is proposed and analyzed based on the electromagnetic phenomenon of the resonator. The equivalent circuit was simply modeled based on the concept of magnetization. A method for achieving a wider operating bandwidth of the negative permeability is provided. The ring resonator with its resonant frequency of 13.56 MHz was designed and its characteristics were examined in terms of S-parameters, effective permeability, loss rate, bandwidth, etc. The circuit and electromagnetic simulation results show an excellent agreement as well as that of theory.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.79-84
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• 2006

A novel design of compact low-pass filter based on microstrip structure and its equivalent-circuit model are developed. The philosophy of the structure behind this novel microstrip low-pass filter is simple as it is composed of a pair of symmetrical parallel coupled-line and an open-stub. With this configuration, a finite attenuation pole near the stopband cutoff frequency is available and adjustable by simply tuning the circuit parameters. Furthermore, the rejection bandwidth of this type of low-pass filter can be extended. In order to validate the feasibility of the proposed design method, a low-pass filter based on a microstrip structure is designed, fabricated, and measured. Experimental results agree very well with the simulation and analytical results.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.870-872
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• 2003

This paper deals with the characteristic analysis of capacitor-run single phase induction motor by equivalent circuit. The unbalanced elliptic rotating magnetic field of the motor was analysed by the symmetrical coordinate method. And this paper check the reliability of characteristic analysis by equivalent circuit in comparison with experimental results and analyse the characteristics of single phase induction motors by changing circuit parameters. Finally, this paper shows the improved effiency design motor by using that result.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.180-182
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• 1995

The equivalent circuit of SLIM is composed of the circuit parameters. They can be obtained from the electromagnetic theory. The accelerating characteristics of SLIM are the best efficiency when synchronous speed changed continuously. The paper outlines a method of acceleration for an accelerated field system in which it is desired to reduce the overall length to a minimum, assuming a limit on the amount of heat which can be generated in the secondary member. The paper then shows that a primary unit designed to give several discrete field speeds only, as opposed to one with continuous speed variation, is not significantly inferior in performance to the latter but is much easier to manufacture.

• ETRI Journal
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• v.22 no.1
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• pp.38-46
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• 2000

The extraction of model parameters for embedded passive components is crucial for designing and characterizing the performance of multichip module (MCM) substrates. In this paper, a method for optimizing the extraction of these parameters using genetic algorithms is presented. The results of this method are compared with optimization using the Levenberg-Marquardt (LM) algorithm used in the HSPICE circuit modeling tool. A set of integrated resistor structures are fabricated, and their scattering parameters are measured for a range of frequencies from 45 MHz to 5 GHz. Optimal equivalent circuit models for these structures are derived from the s-parameter measurements using each algorithm. Predicted s-parameters for the optimized equivalent circuit are then obtained from HSPICE. The difference between the measured and predicted s-parameters in the frequency range of interest is used as a measure of the accuracy of the two optimization algorithms. It is determined that the LM method is extremely dependent upon the initial starting point of the parameter search and is thus prone to become trapped in local minima. This drawback is alleviated and the accuracy of the parameter values obtained is improved using genetic algorithms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.9
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• pp.677-684
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• 2018

In this paper, we propose a method for high-frequency modeling of transformers using the S-parameter. The open and short circuits of the primary and secondary sides were configured, and the reflection coefficient in each circuit was measured using a vector network analyzer. The equivalent circuit elements were extracted from the measured results to model the high-frequency equivalent circuit, and the validity of the method was verified by comparing the measured S-parameters in a 2-port network with the simulation results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.6
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• pp.255-261
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• 2002

Recently, traction motors in trains are supplied with single phase a.c. power. After this power is converted to d.c. power, it is inverted to three phase power to operate traction motors. As going through the process of the conversion, harmonic current is generated in train. The method of conventional analysis on harmonics, studied by RTRI, is modeled with equivalent circuit of ac AT-fed electric railroad system using by the distributed constant circuit. However, this circuit as two-port network model has some difference in comparison with real system. The reason why the conventional method is different from the real system is that the conventional method dose not include three conductor groups, that is catenary, rail, and feeder, and admittance between the conductors for line capacitance. Therefore, this method has a little error. This paper proposes new method to more effectively estimate Harmonic current. In this method, numerous components in electric railway are categorized and each component is defined as a four- port network model. The equivalent circuit for the entire power supply system is also described into a four-port network model with connections of these components. In order to evaluate the efficiency and the accuracy of a proposed method, it is compared with values measured in Kyung-Bu high speed line and ones calculated by the conventional method.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.13-17
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• 2016

The ampere-hour integral method and the open circuit voltage method are integrated via the extended Kalman filter method so as to overcome insufficiencies of the ampere-hour integral method and the open circuit voltage method for estimating battery SOC. The process noise covariance and the measurement noise covariance of the extended Kalman filter method are simplified based on the Thevenin equivalent circuit model, with a proposed simplified SOC estimating method. Verification of DST experiments indicated that the battery SOC estimating method is simple and feasible, and the estimated SOC error is no larger than 2%.

• Journal of Sensor Science and Technology
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• v.15 no.1
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• pp.34-39
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• 2006

This study provides the electrical model of combustible catalytic gas sensor. Physical characteristics such as thermal behavior, resistance change were included in this model. The finite element method analysis for sensor device structure showed that the thermal behavior of sensor is expressed in a simple electrical equivalent circuit that consists of a resistor, a capacitor and a current source. This thermal equivalent circuit interfaces with real electrical circuit using two parts. One is 'power to heat' converter. The other is temperature dependent variable resistor. These parts realized with the analog behavior devices of the SPICE library. The gas response tendency was represented from the mass transferring limitation theory and the combustion theory. In this model, Gas concentration that is expressed in voltage at the model, is converted to heat and is flowed to the thermal equivalent circuit. This model is tested in several circuit simulations. The resistance change of device, the delay time due to thermal capacity, the gas responses output voltage that are calculated from SPICE simulations correspond well to real results from measuring in electrical circuits. Also good simulation result can be produced in the more complicated circuit that includes amplifier, bios circiut, buffer part.