• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.63-68
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• 2002

In a utility interactive photovoltaic generation system, a PWM inverter is used for the connection between the photovoltaic arrays and the utility. The do current becomes pulsated when the conventional inverter system operates in the continuous current mode and dc current pulsation causes the distortion of the ac current waveform. To reduce pulsation of dc input current, This paper presents a Buck-Boost PWM power inverter and its application for residential photovoltaic system. The PWM power inverter is realized by combining two sets of a high frequency Buck-Boost chopper and by making it operate in the discontinuous conduction mode. In this paper, we show the Buck-Boost PWM power inverter circuit, its equivalent circuit and basic differential equations and the power flow characteristics are clarified when the proposed Inverter is interconnected with the utility lines. In conclusion, the proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor

• Journal of Power Electronics
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• 제11권4호
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• pp.606-611
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• 2011

Power electronics is a key technology for electric, hybrid, plug-in hybrid, and fuel cell vehicles. Typical power electronics converters used in electric drive vehicles include dc/dc converters, inverters, and battery chargers. New semiconductor materials such as silicon carbide (SiC) and novel topologies such as the Z-source inverter (ZSI) have a great deal of potential to improve the overall performance of these vehicles. In this paper, a Z-source inverter for fuel cell vehicle application is examined under three different scenarios. 1. a ZSI with Si IGBT modules, 2. a ZSI with hybrid modules, Si IGBTs/SiC Schottky diodes, and 3. a ZSI with SiC MOSFETs/SiC Schottky diodes. Then, a comparison of the three scenarios is conducted. Conduction loss, switching loss, reverse recovery loss, and efficiency are considered for comparison. A conclusion is drawn that the SiC devices can improve the inverter and inverter-motor efficiency, and reduce the system size and cost due to the low loss properties of SiC devices. A comparison between a ZSI and traditional PWM inverters with SiC devices is also presented in this paper. Based on this comparison, the Z-source inverter produces the highest efficiency.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.304-315
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• 2013

In this paper, analysis of cascaded H-bridge multilevel inverter in DTC-SVM (Direct Torque Control-Space Vector Modulation) based induction motor drive for FCEV (Fuel Cell Electric Vehicle) is presented. Cascaded H-bridge multilevel inverter uses multiple series units of H-bridge power cells to achieve medium-voltage operation and low harmonic distortion. In FCEV, a fuel cell stack is used as the major source of electric power moreover the battery and/or ultra-capacitor is used to assist the fuel cell. These sources are suitable for utilizing in cascaded H-bridge multilevel inverter. The drive control strategy is based on DTC-SVM technique. In this scheme, first, stator voltage vector is calculated and then realized by SVM method. Contribution of multilevel inverter to the DTC-SVM scheme is led to achieve high performance motor drive. Simulations are carried out in Matlab-Simulink. Five-level and nine-level inverters are applied in 3hp FCEV induction motor drive for analysis the multilevel inverter. Each H-bridge is implemented using one fuel cell and battery. Good dynamic control and low ripple in the torque and the flux as well as distortion decrease in voltage and current profiles, demonstrate the great performance of multilevel inverter in DTC-SVM induction motor drive for vehicle application.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.411-414
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• 2004

In this paper, a power controller and 3 phase voltage source inverter are proposed for the improvement of weldability of large scaler Mash seam welder. The welder system is designed for the low cost and the improvement of weldability. For this system, the thyristor convertor has performed constant current controlling in the output terminal by using PAM type inverter. We have simulated our algorithm and made a prototype welder for experiment. Through the experiment, we have confirmed the improvement of weldability of our system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.466-470
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• 1991

In this paper, full bridge inverter with IGBT is proposed. By Controlling phase angle difference between 2 arms, PWM controlled high frequency link inverter has VVVF capability. For the simplicity, flexibility and compactness of control circuit, 16 bit single chip microcontroller 8797 BH is used and its characteristic is examined through experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.339-342
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• 2000

Repetitive Load Prediction is proposed for the UPS inverter application of the second order deadbeat controller which is robust against the calculation time delay and the parameter variation and which gets fast response against the load variation. The proposed technique predicts the load current ahead of two sampling time using that the load current is periodic. This is effective under nonlinear load condition. The proposed technique is derived theoretically and verified through simulation and experimental result.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 연구회 합동 학술발표회 논문집
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• pp.13-17
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• 1998

In recent years H-bridge multievel inverters have been focused on and selected as the power inverter in several high voltage and high power application. This paper proposes an new PWM method for the multievel H-bridge inverter systems. The proposed PWM method is a carrierwave-based space vector PWM method which utilizes the phase voltage redundancies considering both the switch and conduction loss of the devices. We describe the new PWM method in detail and the effectiveness of the new PWM method is verified by the simulation results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.747-750
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• 1999

A 30Watt inverter with 300: 1 dimming capability for high luminance, one cell, surface discharge plasma light source for LCD backlight was designed and tested. It was possible to achieve 300:1 dimming control by using the push-pull type inverter with burst-mode dimming control. The surface discharge plasma light cell with luminance of more than 5, 260 cd/$m^2$ was successfully operated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.372-375
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• 1990

A sinusoidal PWM type inverter using 1GBT and a new instantaneous current tracking control stategy is described. Its utilization as an interface for a grid-connected photovoltaic system with maxmum power tracking capability is explaned, and competer simulation along with waveforms are discussed. Finally, experimental results are analysed by state space avarge method to actual grid-connected systems.

• 대한전기학회논문지
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• 제38권8호
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• pp.610-616
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• 1989

The line commutated inverter with GTO forced commutation is described in this paper. The presented circuit has one bypass GTO inserted in DC power side line commutated thyristor inverter. The extended commutation region with additional one GTO-commutation is clearly shown. Also, a new PWM pattern is presented to decrease the effects of harmonics for commutation. A criterion for designing the AC filter parameters to decrease harmonics of AC part is given. The simulation and experimental results clearly show that the proposed circuit can be adapted in the application of regeneration.