• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.4
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• pp.153-153
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• 1985

A method of computer aided design (C.A.D.) is proposed to analize a load circuit of a high frequency induction heating. Various formulas are derived from the properity of the heating load, which is useful for the design of heating materials. A load circuit which is designed by the proposed C.A.D. is realized and tested. The experimental results show in good agreement with the theoritical analysies. Especially the result reveal that the power transfer efficiency increases as the Q and coupling coefficient of the work coil increase.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1073-1078
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• 2012

This paper presented the extraction solution for the coupling coefficient at the magnetically coupled wireless power transmission(WPT) system through the analysis of its equivalent circuit considering the loss. The conventional extraction solution using coupled mode theory is generalized employing the extracted solution considering the load resistance. Consequently, the measuring process of extracting coupling coefficient becomes convenient since the even/odd mode analysis is not necessary. Furthermore, the coupling coefficient obtained from the induced extraction method was in excellent agreement with the coupling coefficient obtained using the ratio of magnetic flux passing through the two loops. The extraction of the accurate coupling coefficient at the magnetically coupled WPT is an essential work to analyze and optimize the WPT system.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.254-256
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• 2006

A Novel way to support typical Thermal Shut Down(TSD) circuit is proposed. In power ICs, on-time or on-duration is the key factor to anticipate an abrupt increase of internal temperature. Such an abrupt raise of the temperature can cause TSD circuit cannot protect on proper time due to the temperature detection delay come from the physical distance or the imperfect coupling between heat sources and detector. The proposed circuit checks the duty ratio touched their maximum or not in every cycle. Once duty ratio touches the maximum duty, new circuit generates the warning signal to the TSD circuit and lowers pre-determined temperature for shut down to compensate the detection delay. The novel circuit will be analyzed to the transistor level and checked the validity by simulation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.3
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• pp.146-152
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• 2001

This paper describes an accurate fault location algorithm based on sequence current distribution factors for a double-circuit transmission system. The proposed method uses the voltage and current collected at only the local end of a single-circuit. This method is virtually independent of the fault resistance and the mutual coupling effect caused by the zero-sequence current of the adjacent parallel circuit and insensitive to the variation of source impedance. The fault distance is determined by solving the forth-order KVL(Kirchhoff's Voltage Law) based distance equation. The zero-sequence current of adjacent circuit is estimated by using a zero-sequence current distribution factor and the zero-sequence current of the self-circuit. Thousands of fault simulation by EMTP have proved the accuracy and effectiveness of the proposed algorithm.

• Journal of Power Electronics
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• v.18 no.3
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• pp.853-862
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• 2018

Frequency coupling in the phase domain is a recently reported phenomenon for phase locked loop (PLL) based three-phase grid-inverter systems. This paper investigates the mechanism and stabilization method for the frequency coupling to the stability of grid-inverter systems. Self and accompanying admittance models are employed to represent the frequency coupling characteristics of the inverter, and a small signal equivalent circuit of a grid-inverter system is set up to reveal the mechanism of the frequency coupling to the system stability. The analysis reveals that the equivalent inverter admittance is changed due to the frequency coupling of the inverter, and the system stability is affected. In the end, retuning the bandwidth of the phase locked loop is presented to stabilize the three-phase grid-inverter system. Experimental results are given to verify the analysis and the stabilization scheme.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1675-1680
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• 2011

Inductive power transfer module(IPTM) is a contact-less power supply device and its application range has been extended to the large capacity devices such as electric vehicles, industrial mover and railway system as well as small capacity devices such as electric toothbrush charger, celluar phone charger, and so on. For railway application, the IPTM will transfer energy while train stops at a station for around 30[sec]. Therefore, equivalent circuit parameters and coupling coefficient of IPTM are an important design factor for the high energy transfer efficiency. This paper investigates the properties of equivalent circuit parameters and coupling coefficient of U-U type IPTM and U-I type IPTM using an analytical method and experimental method. Considering the coupling coefficient of the U-U type is larger than U-I type's, the U-U type is suitable for an application which need maximum power transfer and high efficiency.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1929_1930
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• 2009

Fully embedded tunable bandpass filter (BPF) with inductive coupling circuits is newly designed and demonstrated for UHF TV tuner ranged from 500MHz to 900MHz receivers. Conventional RF tuning circuit with an electromagnetic coupled tunable filter has several problems such as large size, high volume, and high cost, since the electromagnetic coupled filter is comprised of several passive components and air core inductors to be assembled and controlled manually. To address these obstacles, compact tunable filter with inductive coupling circuit was embedded into low cost organic package substrate. The embedded filter was optimally designed to have high performance by using high Q spiral stacked inductors, high dielectric $BaTiO_3$ composite MIM capacitors, varactor diodes. It exhibited low insertion loss of approximately -2dB, high return loss of below -10dB, and large tuning range of 56.3%. It has an extremely compact size of $3.4{\times}4.4{\times}0.5mm^3$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.589-594
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• 2002

The filter of hairpin type can be designed small but has a demerit which a design method is complex. This paper suggests the method that a hairpin line filter is designed with applying a transmission line method and J inverter circuit, accurately calculated the J value and the b parameter. It is considered about the line have no the mutual coupling element with next line to each other. is calculated a length of electric coupling line about coupling element in each inverter stage from the J value and the b parameter. In order to show the validity of the proposed design method, band pass filter of small hairpin line is designed at center frequency 2.6 GHz, with Serenade 8.0 software tool and the simulation characteristics are compared with design results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.497-500
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• 2002

When one is interested in the dynamics of a mechanical system with electric motors, the force generated by the motor is generally considered as only an applied torque or force independent of mechanical state variables such as velocity. For a system operated in non-steady dynamic conditions, however, the usual analysis approach may fail to predict some characteristics in the dynamic behaviors because of electromechanical coupling effects. In this paper, we propose dynamics analysis model in which dc motor dynamics with the electromechanical coupling effects are embedded to mechanical dynamics models. The do motor is modeled based on its equivalent circuit model and included in the dynamics solving algorithm which we developed before, called generalized recursive dynamics formula. The developed dynamic analysis model is effective and realistic for analysis of electromechanical dynamics of a system with do motors. The developed model is evaluated by constructing and simulating the flexible antennas of an artificial satellite driven by do motors.

• Journal of IKEEE
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• v.21 no.3
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• pp.248-251
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• 2017

In this paper, The proposed board is developed by EMI compliant Dash Camera with $360^{\circ}$ omni angle. The proposed board is designed by designing DM and CM input noise reduction circuit and applying active EMI filter coupling circuit. The DM and CM input noise reduction circuit design uses a differential op amp circuit to obtain the DM noise coupled to the input signal via the parasitic capacitance(CP). In order to simplify the circuit by applying the active EMI filter coupling circuit, a noise separator is installed to compensate the noise of the EMI source to compensate the CM and DM active filter simultaneously. In order to evaluate the performance of the board for the proposed EMI response, an authorized accreditation body has confirmed that the electromagnetic certification standard for each frequency band is satisfied.