• 조명전기설비학회논문지
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• 제22권1호
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• pp.87-94
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• 2008

본 연구는 밸리-필 정류기를 이용한 전류 THD 개선 방법을 제시한다. 제안된 회로는 밸리-필 정류기와 부스팅 인덕터를 결합한 구조를 가지며, AC/DC 변환과 PFC를 동시에 수행한다. PWM 스위칭에 따른 부스팅 효과로 입력전류를 제어하여 밸리-필 정류기의 특성을 개선한다. 이 결과는 낮은 전류 THD를 보장한다. 동작 모드와 전류 THD를 분석하고, 최적 부스팅 인덕터를 결정한다. 밸리-필 정류기와 부스팅 인덕터를 채용한 100[W] AC/DC 컨버터를 제작하였고, 시뮬레이션과 실험으로 제안된 방법의 타당성을 검증하였다.

• Journal of Power Electronics
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• 제18권6호
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• pp.1642-1649
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• 2018

A single-stage flyback LED AC-DC converter based on primary-side control under constant current mode is proposed in this study. The proposed converter features low total harmonic distortion (THD) and high power factor (PF). It also consists of a zero-crossing distortion compensation circuit and a variable duty ratio control compensation circuit to deal with the line current distortions caused by fixed duty ratio control. The system model and layout are built in Simplis and Cadence, respectively. The feasibility and performance of the proposed circuit is verified by designing and fabricating an IC controller in the HHNEC $0.35{\mu}m$ 5 V/40 V HVCMOS process. Experimental results show that the PF can reach a level in the range of 0.985-0.9965. Moreover, the average THD of the entire system is approximately 10%, with the minimum being 6.305%, as the input line voltage changes from 85 VAC to 265 VAC.

• 전력전자학회논문지
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• 제23권1호
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• pp.59-65
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• 2018

A new single-stage flyback power converter with PFC for electrolytic capacitor-less LED driver is proposed in this study. This method minimizes the peak-to-average ratio of the LED driving pulsating current by adding the LED driving current near the LED current valley area, as well as the third harmonic component injection into the input current. The reduced peak current value of the LED drive current minimizes the thermal stress of the LED itself, thereby increasing the reliability of the LED, as well as achieving a long lifetime. Simulation and experimental results show the usefulness of the proposed topology.

• International Journal of Computer Science & Network Security
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• 제23권9호
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• pp.162-165
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• 2023

Power can be generated from either renewable or non-renewable sources. Renewable sources are liked to maintain a strategic distance from contamination emanation and rely on upon fossil energizes which is decreasing day by day. The proposed sun powered vitality transformation unit comprises of a sun oriented exhibit, Bidirectional DC-DC converter, single stage inverter and AC. The inverter changes over DC control from the PV board into AC power and offered it to the heap which is associated with the lattice. The photovoltaic sun powered vitality (PV) is the most direct approach to change over sunlight based radiation into power and depends on the photovoltaic impact. The most extreme power point following of the PV yield for all daylight conditions is a key to keep the yield control per unit cost low for fruitful PV applications. Framework associated PV frameworks dependably have an association with people in general power matrix by means of an appropriate inverter in light of the fact that a PV module conveys just dc power. This project presents the new design, Development and Performance Analysis of a Grid Connected PV Inverter. Demonstrate that the proposed framework can lessen the Energy Consumption radically from the power board and give a solid support to the Grid.

• Journal of Power Electronics
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• 제19권5호
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• pp.1099-1107
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• 2019

A soft switching converter with wide voltage range operation is investigated in this paper. A series resonant converter is implemented to achieve a high circuit efficiency with soft switching characteristics on power switches and rectifier diodes. To improve the weakness of the narrow voltage range in LLC converters, an alternating current (ac) power switch is used on the primary side to select a half-bridge or full-bridge resonant circuit to implement 4:1 voltage range operation. On the secondary-side, another ac power switch is adopted to select a full-wave rectifier or voltage-doubler rectifier to achiever an additional 2:1 output voltage range. Therefore, the proposed resonant converter has the capacity for 8:1 (320V~40V) wide output voltage operation. A single-stage hybrid resonant converter is employed in the study circuit instead of a two-stage dc converter to achiever wide voltage range operation. As a result, the study converter has better converter efficiency. The theoretical analysis and circuit characteristics are verified by experiments with a prototype circuit.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 추계학술대회
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• pp.62-64
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• 2018

In two-stage single-phase inverters, inherent double line frequency component is present at both input and output of the front-end converter. Generally large electrolytic capacitors are required to eliminate the ripple. It is well known that the low frequency ripple shortens the lifespan of the capacitor hence the system reliability. However, the ripple can hardly be eliminated without the hardware combined with an energy storage device or a certain control algorithm. In this paper, a novel power-decoupling control method is proposed to eliminate the double line frequency ripple at the front-end converter of the DC/AC power conversion system. The proposed control algorithm is composed of two loop, ripple rejection loop and average voltage control loop and no extra hardware is required. In addition, it does not require any information from the phase-locked-loop (PLL) of the inverter and hence it is independent of the inverter control. In order to prove the validity and feasibility of the proposed algorithm a 5kW Dual Active Bridge DC/DC converter and a single-phase inverter are implemented, and experimental results are presented.

• Journal of Power Electronics
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• 제14권6호
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• pp.1166-1177
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• 2014

A new type of topology with medium-frequency-transformer (MFT) isolation for medium voltage wind power generation systems is proposed in this paper. This type of converter is a high density power conversion system, with high performance features suitable for next generation wind power systems in either on-shore or off-shore applications. The proposed topology employs single-phase cascaded multi-level AC-AC converters on the grid side and three phase matrix converters on the generator side, which are interfaced by medium frequency transformers. This avoids DC-Link electrolytic capacitors and/or resonant L-C components in the power flow path thereby improving the power density and system reliability. Several configurations are given to fit different applications. The modulation and control strategy has been detailed. As two important part of the whole system, a novel single phase AC-AC converter topology with its reliable six-step switching technique and a novel symmetrical 11-segment modulation strategy for two stage matrix converter (TSMC) is proposed at the special situation of medium frequency chopping. The validity of the proposed concept has been verified by simulation results and experiment waveforms from a scaled down laboratory prototype.

• Journal of Power Electronics
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• 제15권4호
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• pp.1026-1034
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• 2015

In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.400-409
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• 1997

Design of single stage AC/DC converter with high power factor and high efficiency based on half-bridge topology for low power application is proposed. To obtain design equations, modelling and detailed analysis are performed. The proposed converter gives and power factor and high efficiency by employing aynchronous rectifiers. To verify the performances of the proposed converter 90W-converter has been designed. This prototype converter meets IEC555-2 requirements with near unity power factor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.709-712
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• 1998

A new ZVS-CV PWM converter with power factor correction (PFC) function is presented in this paper. The new topology is a integration of a boost converter and a ZVS-CV topology in a single power conversion stage. The new converter can be regulated in pulse-width modulation (PWM) by universal integrated control circuits. Some design considerations are given in detail. A laboratory prototype has been implemented to show the feasibility of the approach and the analysis.