• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1120-1122
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• 2002

Switching power supply are widely used in many industrial field. Power factor improvement and harmonic reduction technique is very important in switching power supply. The power factor correction (PFC) circuit using boost converter used in input of power source is studied in this paper. It is analyzed distortional situations and harmonics of input currents that presented at continuous conduction mode(CCM) of boost PFC circuit. It is done simulations of harmonics distribution according to load variation by using PSPICE and MATLAB. From the actual experiment of boost PFC circuit the validity of the analysis is confirmed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.417-422
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• 1997

This paper proposed that a AC-DC Converter topology of high power factor with soft switching mode operates with four chopper connecting a number of parallel circuit. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer is included to confirm the validity of the analytical results. The partial resonant circuit makes use of a inductor using step up and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in partial resonant circuit makes charging engergy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.147-150
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• 2004

Maximum power point tracking for PV systems traditionally uses either perturbation and observation method or incremental conductance method. Both methods require modulation of the output voltage and this leads to significant power loss. In this paper, a method, which senses output circuit voltage and short circuit current and use the above two parameters for optimum control with a fuzzy controller, is introduced. The short circuit current of PV cell represents illumination, and the output circuit voltage carry on information about the temperature. PCS(power conditioning system) is controlled not only feed to inverter for stability voltage variation despite of variety external environment, but also operate in order to feeding voltage and current at maximum power point by boost type chopper.

• 전기학회논문지
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• 제64권1호
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• pp.196-200
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• 2015

The switching noise in the power electronics of the power conversion equipment (Power Conditioning System) for large energy storage devices are generated. Since the burst-level transient noise from being generated in the power system at a higher power change process influences the control circuit of the low voltage driver circuit. Noise may cause the malfunction of the control device even if no dielectric breakdown leads to a control circuit. To overcome this, this paper proposes the installation of an additional nano-surge protection device on the power supply DC output circuit of the battery management unit.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.31-34
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• 1998

In this paper, a Single-phase Active Rectifier(SAR) with high power factor capability for inverter air-conditioner is adopted for satisfying the international standards of input current harmonics, IEC 1000-3-2. Comparing the conventional boost power factor correction circuit, one diode drop is reduced in the power flow path of the SAR circuit, so the system efficiency is improved. To apply the control IC, such as UC3854, ML4821 and so forth, to the SAR, the adequate sensing circuits are proposed. The design rules of passive components and two control loops are also presented. The prototype SAR circuit with 3㎾ power consumption is builted and tested to verify the operation of the proposed circuit.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.79-84
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• 1998

A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) PWM converter with low output current ripple is presented. A simple auxiliary circuit added in the secondary provides ZVZCS conditions to primary switches, ZVS for leading-leg switches and ZCS for lagging-leg switches, as well as reduces the output current ripple (ideally zero ripple). The auxiliary circuit includes neither lossy components nor additional active switches which are demerits of the previously presented ZVZCS converters. Many advantages including simple circuit topology, high efficiency, low cost and low current ripple make the new converter attractive for high performance high power (＞1kW) applications. The principle of operation, features and design considerations are illustrated and verified on a 2.5kW, 100KHz IGBT based experimental circuit.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.421-423
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• 2005

A bootstrap circuit for floating power supply has the advantage of being simple and inexpensive. However, the duty cycle and on-time are limited by the requirement to refresh the charge in the bootstrap capacitor. Hence, this paper deals with a design of charge pump circuit for a floating gate power supply of an IPM. The operation of the proposed circuit applied by three-phase inverter system for driving induction motor are verified through the experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.1001-1004
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• 2007

This paper proposes a novel RGB-LED (light emitting diode) backlight system, for 32" LCD TVs, accompanied by a new X-Y Channel driving method in which its row and column switches control the individual division screen. This proposed driving method is able to produce division driving effects such as image improvement and reduced power consumption. Not only that, the number of driver needed in this method, that is 3 power supplies with 3*(m+n) switches, is much fewer than that of cluster driving method, that is 3*(m*n) driver.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.492-496
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• 2004

When using a conventional power factor correction circuit, a comparatively huge capacitor is used to boost-up output voltage. It has a large amount of harmonic distortion in the input current waveform. To improve the input current waveform of diode rectifiers, we propose a new operating principle for the power factor correction circuit. Due to the fact that the proposed circuit uses smaller ones and a smaller reactor, the output voltage increases and obtains higher input current waveforms. These are suitable for the harmonics guidelines. The proposed circuit is able to obtain higher power factor and efficiency. Also, it has reduced switching loss and held over-shooting by using an inverter of eliminated dead-time HPWM that has non-linear impedance circuits to make up diodes, capacitance and a reactor. We compared the conventional PWM inverter and proposed HPWM inverters and found that a high input power factor of 97[%] and an efficiency of 98[%] were also obtained.

• 전력전자학회논문지
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• 제25권6호
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• pp.477-483
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• 2020

This study proposes a DQ synchronous reference frame model of a series-parallel tuned inductive power transfer (SP-IPT) system. The wireless power transmission system experiences control difficulty because the transmitter-side controller cannot directly measure the receiver-side load voltages and currents. Therefore, a control-oriented circuit model that shows the dynamics of the IPT system is required to achieve a well-behaved controller. In this study, an equivalent circuit model of the SP-IPT system in a synchronously rotating reference frame is proposed using the single-phase DQ transformation technique. The proposed circuit model is helpful in modeling the dynamics of the voltages and currents of the transmitter- and receiver-side resonant tanks and loads. The proposed circuit model is evaluated using frequency- and time-domain simulation results.