• 전력전자학회논문지
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• 제6권3호
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• pp.265-272
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• 2001

기존의 전자레인지의 마그네트론 구동용 전원장치는 성층 철심을 사용한 60[Hz]고압 변압기, 큰 용량의 콘덴서와 싸이리스터를 이용한 위상제어 회로를 사용하기 때문에 부피가 크고 무거우며, 저효율의 단점을 가지고 있다. 본 논문은 출력 600[W]마그네트론을 장착한 전자레인지의 전원장치로 최대출력1[kW], 스위칭 주파수20[kHz]의 Phase-shifted Full-Bridge(FB)Zero-Voltage-Switched(ZVS) PWM 컨버터의 사용을 제안하고, 이를 개발.적용하여 전체 시스템의 경량화 및 고전력밀도의 목적을 달성하였다.

• 전기학회논문지
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• 제64권5호
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• pp.718-725
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• 2015

This paper proposes a novel level-shifted PWM (LS-PWM) strategy for fault tolerant cascaded multilevel inverter. Most proposed fault-tolerant operation methods in many of studies are based on a phase-shifted PWM (PS-PWM) method. To apply these methods to multilevel inverter systems using LS-PWM, two additional steps will be implemented. During the occurrence of a single-inverter-cell fault, the carrier bands scheme is reconfigured and modulation levels of inverter cells are reassigned in this proposed fault-tolerant operation. The proposed strategy performs balanced three-phase line-to-line voltages and line currents when a switching device fault occurs in a cascaded multilevel inverter using LS-PWM. Simulation and experimental results are included in the paper to verify the proposed method.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권4호
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• pp.484-492
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• 2015

This paper proposes a PWM phase-shift circuit to make that the LED lighting system distributes the channel currents evenly for any number of LED strings by generating evenly phase-shifted PWM signals for multiple LED driver ICs. The evenly distributed channel currents reduce the peak current, the decoupling capacitor size, and EMI noise. The PWM phase-shift circuit makes an arbitrary degree of PWM phase-shift by using a resistor and a capacitor. It measures the RC delay once. It reduces the number of external resistors and capacitors by providing zero and 180 degree phase-shift modes requiring no resistor and capacitor. An LED driver IC with the PWM phase-shift circuit was fabricated with a $0.35{\mu}m$ BCDMOS process. The PWM phase-shift circuit receives a PWM signal of 50 Hz~20 kHz at $f_{CLK}=450kHz$ and it generates a $0{\sim}360^{\circ}$ phase-shifted PWM signal with $R=0{\sim}1.1M{\Omega}$ at C=1 nF and $f_{PWM}=1kHz$. The measured phase errors are 1.74~3.94% due to parasitic capacitances.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.397-398
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• 2014

Phase Shifted PWM은 각각의 셀이 동일한 스위칭 주파수로 PWM을 수행하므로 전압지령의 크기와 관계없이 셀 간의 전력은 동일하나, 각 셀 출력 전압의 위상이 다르므로 무부하 운전이나 부하의 급변동 시 발생하는 회생이 특정 셀에 집중되고 전압지령과 실제 출력전압 사이의 위상 차이가 존재하는 단점을 가지고 있다. 반면 기존 Level Shifted PWM은 전압지령의 크기에 따라 각 셀 간의 스위칭 조건이 다르고 동일 전력 분배가 되지 않는 문제를 가지고 있어 이를 개선하는 Level Shifted PWM 방법에 대해서는 이미 연구가 진행된 상태이다. 본 논문에서는 제어기가 분산화된 H-브릿지 멀티레벨 인버터에 각 셀의 스위칭 조건을 동일하게 유지하는 Level Shifted PWM을 적용하기 위해서 전압지령을 보정하는 방법을 사용하였고 시뮬레이션과 시험을 통해 제어기가 분산화된 H-브릿지 멀티레벨 인버터에 적용 가능함을 증명하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.218-219
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• 2016

This paper present Phase Shifted with carrier based on Sinusoidal PWM(SPWM) by using Cascaded NPC/H-birdge converter. The proposed Phase Shifted PWM method is adding third harmonic injection in switching signal. The advantage of the proposed method is reducing the voltage and capacity of the capacitor. This paper compare general Phase Shifted method with proposed Phase Shifted method that added the third harmonic injection. Each PWM method is tested without considering the switching loss by using PSIM 9.1.4 simulation.

• Journal of Power Electronics
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• 제8권3호
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• pp.201-209
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• 2008

This paper presents the modeling and design of a digital controller for a phase-shifted full-bridge converter (PSFBC) in a discrete-time domain. The discretized PSFBC model is first derived and then analyzed considering the sampling effect and the system parameters. Based on this model, the digital controller is directly designed in a discrete-time domain. The simulation and experimental results are provided to show the validity of the proposed modeling and controller design.

• Journal of Power Electronics
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• 제19권1호
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• pp.134-145
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• 2019

A single-phase step-up five-level inverter topology with a new phase-shifted pulse width modulation (PS-PWM) strategy is proposed in this paper. When compared with conventional single-phase five-level inverter topologies, the proposed topology can realize multilevel inversion with a double step-up ratio, a reduced number of switching devices and self-balanced capacitor voltages. When compared with the conventional PS-PWM strategy, the new PS-PWM strategy can be implemented with one carrier reduced, which makes it much easier to implement in a digital signal processor (DSP) system. Experimental results have been presented to verify the effectiveness of the proposed inverter and the PS-PWM strategy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.392-394
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• 1996

This paper is to describe how to apply the Phase-shifted Full Bridge 100kHz high frequency soft-switching PWM method to 48[V], 200[A] DC/DC converter. The soft-switching is achieved from light load to full load by using phase-shifted zero voltage switching method with additional capacitors besides the MOSPET's of the right leg even though the leakage inductance of high frequency transformer is designed small. This method can reduce the switching tosses, EMI problems, and increase the effective duty. Also, this paper includes the simulation, analysis, and experiment results of the DC/DC converter unit.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.140-145
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• 2001

This paper proposes to use a 20[kHz] phase­shifted Full-Bridge (FB) Zero-Voltage-Switched (ZVS) PWM converter in order to drive a 600[W] magnetron, and analyzes the operational modes in a switching period. Additionally, the controller of the average anode current is designed. Simulation studies and experiments verify that the proposed converter and the average anode current controller shows good performance to drive the magnetron.

• Journal of Power Electronics
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• 제16권2호
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• pp.473-479
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• 2016

In this paper, the PSC PWM method is chosen as the optimal modulation method for a 20MW VSC HVDC, with consideration of the harmonic distortion of the output voltage, the switching frequency, and the control implementation difficulty. In addition, a new PSC PWM method is proposed in order to achieve an easy application and to solve the redundant control problems encountered in the previous PSC PWM method. To verify the proposed PSC PWM method, PSCAD/EMTDC simulations for an 11-level MMC RTDS HILS test and an 11-level MMC prototype converter test were performed. As can be seen from the results of these tests, the proposed PSC PWM method shows good results in an 11-level MMC with redundant sub-modules.