• 조명전기설비학회논문지
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• 제27권5호
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• pp.74-80
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• 2013

This paper presents the transient behavior of the switching surge voltages generated by interruption of DC ground fault currents flowing through metal flexible conduits. All fault circuits consist of line parameters such as resistance, inductance, capacitance and conductance. The use of nonmagnetic metal conduits should be taken into account in order to reduce the inductance of battery charger distribution circuits. The frequency-dependent circuit parameters of metal flexible conduits were measured. The switching surge voltages generated at the ground fault circuit consisted of steel-galvanized alloy and aluminium conduits were investigated. As a result, the impedances of metal flexible conduits are significantly increased over the range of the frequency above 10 kHz and the switching surge voltages generated along aluminium flexible conduit are lower than those along steel-galvanized alloy conduit when DC fault current is interrupted.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2262-2270
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• 2015

Generally, internal parameters of the motors and generators can be divided to the resistance and inductance components. They can become a cause of the changing internal parameters because they have sensitive characteristics due to external conditions. The changed parameters can generate the outputs which include error values from the speed and current controllers. Also, it can bring the temperature increase and mechanical damage to the system. Therefore, internal parameters of the motors and generators need to obtain their values according to the external conditions because it can prevent the mechanical damage caused by the changed parameters. In this paper, the off-line parameter identification method is verified using the Goertzel algorithm. The motor used in the simulation and experiments is an interior permanent magnet synchronous motor (IPMSM), and the proposed algorithm is verified by the simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.61-63
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• 1999

This paper presents an efficient method for analysis of magnetodynamic system using frequency-dependent parameters. In equivalent electric circuit of linear magnetodynamic system, parameters of inductance and resistance are not constant since they vary with its driving frequency. Once frequency-dependent parameters of equivalent electric circuit for a given system are extracted, they can be used to analyze various characteristics of system. We use the Fourier transform, the high-order sensitivity method and Taylor series in order to efficiently extract the frequency-dependent parameters of magnetodynamic system. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency.

• 전기학회논문지
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• 제57권3호
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• pp.446-452
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• 2008

To design a spiral inductor a genetic algorithm is applied with fast computing technique. For the inductance extraction of the given geometry the fast multipole method is used, also the distributed computing technique using 10 personal computers is introduced for the massive computation of the genetic algorithm. A few important design parameters are used as genes for the optimization in the genetic algorithm. The target function is chosen as mean square error of the inductance at several sampling frequency points. A large-scaled inductor is fabricated and compared with the simulated data.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.645-648
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• 1998

We used a three-dimensional inductance extraction program, Fasthenry for optimal design of the spiral inductors on silicon substrate. The inductance and quality factor of the spiral inductors with various design parameters were calculated so that the optimal parameter value was determined. The spiral inductors then were fabricated using different foundary processes and were measured using the network analyzer and microwave probes. The pad and other parasitics of measurement system were de-embedded using the y-parameter calibration technique. the inductors fabricated using the LG 0.8um process and HP 0.5um process showed the quality factor of 5.8 and 3, respectively. Finally the equivalent circuit farameters of the spiral inductors on silicon substrate were extracted from the measurement data using the matlab.

• 전력전자학회논문지
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• 제2권2호
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• pp.49-56
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• 1997

스위치드 리럭턴스 전동기(switched reluctance motor : 이하 SRM 이라 칭함)는 가변 인덕턴스 프로파일의 비선형성과 리플성분이 포함된 펄스전류에 구동되는 본질적인 특성 때문에 토오크는 맥동성분을 포함한다. 본 논문에서는 토오크의 맥동에 영향을 미치는 전류파형 형태를 고찰하고, 속도나 부하에 관계없이 어드밴스 각(advance angle)와 여자전압을 제어함으로써 토오크 맥동을 저감할 수 있는 단일 펄스모드 스위칭 제어방법을 제안하였다. 그리고 설계 제작된 6/4 SRM을 이용하여 제안한 스위칭 제어방법의 타당성을 실험적으로 확인하였다.

• 전기학회논문지
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• 제56권4호
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• pp.645-650
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• 2007

This paper proposes a parameter estimation technique of a power transformer. Based on the combined equation, it estimates separately the primary and secondary leakage inductances using the least square method from the instantaneous voltages and currents in the steady state. The performance of the proposed technique was investigated by varying the cut-off frequency of the filter and the number of samples per cycle. The estimated values are obtained based on the average value for 41 cycle.

• Journal of Power Electronics
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• 제12권4호
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• pp.559-566
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• 2012

A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

• ETRI Journal
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• 제28권1호
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• pp.115-118
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• 2006

In this letter, a simple model parameter extraction methodology for an on-chip spiral inductor is proposed based on a wide-band inductor model that incorporates parallel inductance and resistance to model skin and proximity effects, and capacitance to model the decrease in series resistance above the frequency near the peak quality factor. The wide-band inductor model does not require any frequency dependent elements, and model parameters can be extracted directly from the measured data with some curve fitting. The validity of the proposed model and parameter extraction methodology are verified with various size inductors fabricated using $0.18\;{\mu}m$ CMOS technology.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.248-249
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• 2010

This paper deals with the design and experiment of 85kW(17kV, 5A) high voltage power supply for 60kW industrial magnetron. The power supply was designed based on the series resonant converter discontinuous conduction mode(DCM) which has the current source characteristic and high efficiency. In addition, inevitable leakage inductance of high voltage transformer can be used as resonant inductance. The basic analysis of full-bridge series resonant converter with transformer is given and the relationships between resonant tank parameters and input, output specification was derived. Simulation and experiment was done with variable switching frequency and their results verify the theoretical analysis.