• 전기학회논문지P
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• 제66권2호
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• pp.58-62
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• 2017

This paper presents a novel prototype of the resonant AC link snubber circuit for the three-phase sinwave soft-switching PWM inverter. In principle, its operating principle is described, and the performance evaluations of the specific instantaneous space voltage modulated three-phase sinewave soft switching PWM inverter incorporating a resonant AC link snubber is illustrated, and evaluated, introducing the specific space voltage vector modulation implementation. It is conferred that the validity of three-phase soft-switching inverter treated here in setup experiment.

• Journal of Power Electronics
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• 제4권2호
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• pp.77-86
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• 2004

This paper presents a novel three-phase power module bridge type auxiliary resonant AC link snubber for the three-phase voltage-fed sinwave soft switching PWM inverter operating under specific instantaneous space voltage vector modulation. The operating principle of this resonant snubber is described for current source load model during one switching period, along with its design approach based on the simulation data. The performance evaluations of space vector modulation three-phase sinewave soft switching inverter with a new three-phase active auxiliary resonant AC link snubber are discussed as compared with those of three-phase voltage source-fed sinewave hard switching PWM inverter with a standard space voltage vector modulation strategy. The power loss analysis and conventional efficiency estimation of three-phase soft switching PWM inverter using ICBT modules are carried out including all the conduction power losses based upon the measured v-i characteristics of IGBT and its antiparallel diode as well as their switching losses.

• 대한기계학회논문집
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• 제19권8호
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• pp.1901-1906
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• 1995

The frequency response functions of systems incorporating a non-linear cubic stiffness subject to sinusoidal excitation are derived using the Volterra series and the convergence characteristics investigated. It is shown that the series representation of the frequency response functions converges only when the sinewave input amplitude is within a certain range. Within the range of convergence the frequency response function based on the Volterra series approaches the analytical one as more higher order frequency response function terms are included. Proposed is a criterion for the studies systems to predict approximately the range of sinewave input amplitude for which the series representation of the frequency response functions converges.

• Journal of Power Electronics
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• 제7권2호
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• pp.109-117
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• 2007

In this paper, a novel proposal for a utility-interactive three-phase soft commutation sinewave PWM power conditioner with an auxiliary active resonant DC-link snubber is developed for fuel cell and solar power generation systems. The prototype of this power conditioner consists of a PWM boost chopper cascaded three-phase power conditioner, a single two-switch auxiliary resonant DC-link snubber with two electrolytic capacitors incorporated into one leg of a three-phase V-connection inverter and a three-phase AC power source. The proposed cost-effective utility-interactive power conditioner implements a unique design and control system with a high-frequency soft switching sinewave PWM scheme for all system switches. The operating performance of the 10 kW experimental setup including waveform quality, EMI/RFI noises and actual efficiency characteristics of the proposed power conditioner are demonstrated on the basis of the measured data.

• 산업기술연구
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• 제26권B호
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• pp.243-248
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• 2006

The purpose of this study is to design a body-fat measurable electronic scale which can measure body impedance and weight. The hardware configuration of this system for the body-fat measurement includes a sinewave constant current generator, a analog switch circuit and a microprocessor with peripheral interface as well as electronic scale circuit. And the dedicated software is also designed for calculating body fat and body composition analysis from the result of the measurement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.342-344
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• 1994

In this paper, the dynamic characteristics of the existing filter is analyzed to obtain a sinewave current from full bridge inverter with low pass LC filter. The Chevshev's filter, which is most typical low pass filter, is adopted for this investigation and driven controller of full bridge inverter used EV8097BH one-chi p controller.

• 대한전자공학회논문지SD
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• 제43권8호
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• pp.6-12
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• 2006

최근 이동통신 시스템의 급속한 발전에 따라, 관련된 이동통신 부품의 개발이 요구되고 있으며, 특히 기존의 이동통신 부품 소형화와 병행하여, 주변회로 및 소자와의 복합화가 진행되고 있다. 본 논문에서는 WCDMA(UMTS)용 다중출력 VC-TCXO (Voltage Controlled-Temperature Compensated Crystal Oscillator)는 내부에 CMOS 인버터를 추가로 내장하여 기본적인 정현파(Clipped sinewave) 출력에 추가로 CMOS 출력을 가능하게 하였고, 또한 WCDMA 시스템에서 요구하는 VC-TCXO 특성을 만족하였다. 또한 기준 발진기의 중요한 특성인 위상잡음(Phase noise) 특성 및 주파수 단기 안정도 특성(Frequency short term stability)도 WCDMA(UMTS)의 기준을 만족하였다. 본 논문에서는 기준 주파수로 26MHz를 사용하고 있지만, 10MHz에서 40MHz까지 다양하게 응용될 수 있다.

• 전기학회논문지P
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• 제67권2호
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• pp.63-69
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• 2018

In this paper, the operation principle of a bi-directional switch type resonant AC link snubber circuit was described, together with the practical design procedure, which employs in the proposed power module bridge package type resonant AC link snubber. The novel prototype of power module bridge package type resonant AC link snubber-assisted voltage type sinewave soft switching PWM inverter using IGBT power module was demonstrated herein. It was verified that both the auxiliary power switches in this resonant AC link snubber circuit and the main power switches commutate under the condition of soft switching commutation principle. In addition, the power losses of the new soft switching inverter treated here were analyzed by implementing the experimental data of the IGBT and diode v-i characteristics in addition to switching power loss characteristics into our original computer simulation software developed by the authors. Then, the voltage type sinewave soft switching PWM inverter was high efficiency than that of hard switching PWM inverter, along with performance operation waveforms. In the future, the comparative feasibility study of power module bridge type resonant AC link snubber and its related soft switching inverter in addition to the other types resonant snubber assisted soft switching inverter should be done from a practical point of view.

• Journal of Power Electronics
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• 제3권4호
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• pp.249-258
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• 2003

This paper presents a high-efficient and cost effective three-phase AC/DC-DC/AC power conversion system with a single two-switch type active Auxiliary Resonant DC Link (ARDCL) snubber circuit, which can minimize the total power dissipation. The active ARDCL snubber circuit is proposed in this paper and its unique features are described. Its operation principle in steady-state is discussed for the three phase AC/DC-DC/AC converter, which is composed of PWM rectifier as power factor correction (PFC) converter, sinewave PWM inverter. In the presented power converter system not only three-phase AC/DC PWM rectifier but also three-phase DC/AC inverter can achieve the stable ZVS commutation for all the power semiconductor devices. It is proved that the proposed three-phase AC/DC-DC/AC converter system is more effective and acceptable than the previous from the cost viewpoint and high efficient consideration. In addition, the proposed two-switch type active auxiliary ARDCL snubber circuit can reduce the peak value of the resonant inductor injection current in order to maximize total system actual efficiency by using the improved DSP based control scheme. Moreover the proposed active auxiliary two-switch ARDCL snubber circuit has the merit so that there is no need to use any sensing devices to detect the voltage and current in the ARDCL sunbber circuit for realizing soft-switching operation. This three-phase AC/DC-DC/AC converter system developed for UPS can achieve the 1.8% higher efficiency and 20dB lower conduction noise than those of the conventional three-phase hard-switching PWM AC/DC-DC/AC converter system. It is proved that actual efficiency of the proposed three-phase AC/DC-DC/AC converter system operating under a condition of soft switching is 88.7% under 10kw output power.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.483-486
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• 2003

This paper presents a small capacitance measuring circuit for capacitive sensors. The proposed circuit consists of sinewave generator, detector and demodulator. Results of experiments are shown that the circuit can be able to measure small capacitance exiting in a capacitive sensor filled with a vegetable oil. The sensitivity of the circuit is from 0.4V/pF to 4V/pF and the resolution is from 0.0025 pF to 0.00025 pF.