scholarly journals A Quasi-Resonant ZVZCS Phase-Shifted Full-Bridge Converter with an Active Clamp in the Secondary Side

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2868 ◽  
Author(s):  
Duong Tran ◽  
Nam Vu ◽  
Woojin Choi

A novel Pulse-Width-Modulation (PWM) quasi-resonant active-clamp phase-shifted full-bridge converter is presented and analyzed in this paper. In the proposed topology, an active-clamp switch and a clamp capacitor that resonates with the leakage inductance of transformer are employed at the secondary side. The active-clamp circuit helps all of the primary switches in achieving both zero-voltage switching (ZVS) turn-on and nearly zero-current switching (ZCS) turn-off over the entire load range, and resets the primary current during the freewheeling interval. The operation of the active-clamp circuit eliminates voltage ringing across the rectifier. In addition, the secondary diodes can achieve ZCS turn-off, which removes the reverse recovery problem of diodes, and the active-clamp switch can achieve ZCS turn-on. A 3.5-kW prototype was built to verify the performance of the proposed converter. A maximum efficiency of 97.6% was achieved under a 2-kW load, and an efficiency of more than 96% was achieved even under a light load.

2016 ◽  
Vol 25 (10) ◽  
pp. 1650128 ◽  
Author(s):  
Sevilay Cetin

This study presents an improved zero voltage switching (ZVS) boost converter with an active snubber cell providing soft switched operation for all semiconductors. The active snubber cell reduces the reverse recovery loss of the boost diode and also provides the zero voltage transition (ZVT) Turn-on and ZVS Turn-off for the boost switch. The zero current switching (ZCS) Turn-on and ZVS Turn-off for the snubber switch is also achieved. All diodes in the converter can be operated with soft switching (SS). In the snubber cell, SS energy can be transfered effectively to the output by the use of a snubber inductor and a capacitor. This energy transfer allows the use of additional parallel connected capacitor to the boost switch to provide ZVS turning off. There is no additional voltage and current stress on the boost switch and boost diode. The voltage stress of the snubber switch is also limited by the output voltage and the current stress of the snubber switch is reduced by the energy transfer to the output. SS operating of the semiconductors is maintained at very wide load ranges. The operation of the proposed converter is presented with a detailed steady state analysis. The predicted theoretical analysis is validated by a prototype with 500[Formula: see text]W output power and 100[Formula: see text]kHz operating frequency. The measured maximum efficiency values are obtained as approximately 97% and 85.4% at full load and 10% load conditions, respectively.


Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 184 ◽  
Author(s):  
Ming Lu ◽  
Xiaodong Li

In this paper, a semi-dual-active-bridge (S-DAB) DC/DC converter with primary pulse-width modulation plus secondary phase-shifted (PPWM + SPS) control for boost conversion is analyzed in detail. Under the new control scheme, all effective operation modes are identified at first. Then, the working principle, switching behaviour, and operation range in each mode are discussed. Compared with conventional secondary phase-shifted control, PPWM + SPS control with two controllable phase-shift angles can extend the zero-voltage switching (ZVS) range and enhance control flexibility. In addition, an effective control route is also given that can make the converter achieve at the global minimum root-mean-square (RMS) current across the whole power range and avoid the voltage ringing on the transformer secondary-side at a light load. Finally, a 200 W prototype circuit is built and tested to verify correctness and effectiveness of theoretical results.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 363 ◽  
Author(s):  
Alfredo Medina-Garcia ◽  
Manfred Schlenk ◽  
Diego Morales ◽  
Noel Rodriguez

In this article, an innovative power adaptor based on the asymmetrical pulse width modulation (PWM) flyback topology will be presented. Its benefits compared to other state-of-the-art topologies, such as the active clamp flyback, are analyzed in detail. It will also describe the control methods to achieve high efficiency and power density using zero-voltage switching (ZVS) and zero-current switching (ZCS) techniques over the full range of the input voltage and the output load, providing comprehensive guidelines for the practical design. Finally, we demonstrate the convenience of the proposed design methods with a 65 W adaptor prototype achieving a peak efficiency of close to 95% and a minimum efficiency of 93.4% at full load over the range of the input voltage, as well as a world-class power density of 22 W/inch3 cased.


Author(s):  
Toni Prasetya ◽  
F. Danang Wijaya ◽  
Eka Firmansyah

Enhancing the switching frequency can increase the power density of a fullbridge dc-dc converter. However, power loss in switches will increase due to the intersection of voltage and current during turn-on and turn-off transition process. The switching power loss can be reduced by making the condition of zero voltage switching (ZVS) which in this study is obtained by using the phase-shifted PWM method. Achieving this condition requires appropriate parameters such as deadtime, leakage inductance, and the primary current of transformer in sufficient value. In this study, ZVS is achieved when the transformer leakage inductance of 14.12 μH is added with external inductance of 24.29 μH which is installed in series with transformer and when the primary current of transformer is more than 1.289 A.


2013 ◽  
Vol 284-287 ◽  
pp. 2472-2476
Author(s):  
Chien Hsuan Chang ◽  
Hung Liang Cheng ◽  
Chun An Cheng ◽  
En Chih Chang

Light emitting diodes (LEDs) have substituted for incandescent bulbs and fluorescent lamps gradually in the residential, industrial and commercial lighting applications. This paper proposes an active clamp forward converter with the sequential color display (SCD) control to drive red, green and blue (RGB) LED arrays. Both of the main switch and the auxiliary switch can turn on under zero voltage switching (ZVS), resulting in high system efficiency. RGB LED arrays are sequentially driven by the same converter, which can save components and reduce cost significantly. Besides, the pulse-width modulation (PWM) control is applied to achieve a large chromaticity variation. The operation principles of the proposed LED driver are addressed. Experimental results of a 100W laboratory prototype are used to verify the feasibility and validity of the theoretical predictions.


2021 ◽  
Vol 9 (06) ◽  
pp. 663-672
Author(s):  
Anukriti Sharma ◽  
◽  
Navdeep Singh ◽  

This paper presents the performance analysis of proposed circuit of Single-Phase Reduced Order AC-AC Resonant Frequency Converter. AC-AC converter is minimized number of switches for multi-operation and resonant converter is converter work on the principle of ZCS (Zero Current Switching) and ZVS (Zero Voltage Switching) combining both topology, which provide better output with reduce THD and switching losses. A mathematical modeling is done for proper value of used parameters in converter. The output of converter is improved by applying Modulation technique in this converter we are using Trapezoidal Pulse Width Modulation (TPWM) for the better performance and control. THD of the converter is calculated by using MATLAB simulation software. MATALB simulation of AC –AC Resonate Frequency Converter is done by using MOSFET as switch.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5290
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Jenn-Jong Shieh

A non-isolated buck converter, together with resonance and zero voltage transition to achieve zero voltage switching (ZVS) and zero current switching (ZCS), is presented herein to upgrade the conversion efficiency. In this circuit, the main switch and the auxiliary switch are connected to the common ground so as to make the two switches easily driven. Furthermore, these two switches take time division multiplexing operation. In addition, the pulse width modulation (PWM) control technique is utilized so as to render the output inductor and capacitor easily designed. In this paper, the theoretical derivation is first introduced, and secondly, some experimental results are provided to demonstrate the effectiveness of the proposed topology.


2014 ◽  
Vol 3 (3) ◽  
pp. 101-121 ◽  
Author(s):  
S. Aiswariya ◽  
R. Dhanasekaran

This paper proposes an AC-DC converter with the application of active type soft switching techniques. Boost converter with active snubber is used to achieve power factor correction. Boost converter main switch uses Zero Voltage Transition switching for turn on and Zero Current Transition switching for turn off. The active snubber auxillary switch uses Zero Current Switching for both turn on and turn off. Since all the switches of the proposed circuit are soft switched, overall component stress has been greatly reduced and the output DC voltage is expected to have low ripples. A small amount of auxillary switch current is made to flow to the output side by the help of coupling inductor. The proposed circuit is simulated using MATLAB Simulink. All the related waveforms are shown for the reference. The power factor is measured as 0.99 showing that the input current and input voltage is in phase with each other. The PFC circuit has very less number of components with smaller size and can be controlled easily at a wide line and load range.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 715 ◽  
Author(s):  
Jing-Yuan Lin ◽  
Yi-Feng Lin ◽  
Sih-Yi Lee

This paper proposes a novel multi-element resonant converter with self-driven synchronous rectification (SR). The proposed resonant converter can achieve a zero-voltage-switching (ZVS) operation from light load to full load, meanwhile, the zero-current-switching (ZCS) can achieve rectifiers of a secondary-side. Therefore, the switching losses can be significantly reduced. Compared with an LLC resonant converter, the proposed resonant converter can be effective to decrease the circulating energy through the primary-side of the transformer to output a load and provide a wide voltage gain range for over-current protection as well as decreasing the inrush current under the start-up condition. Moreover, the proposed converter uses a simple current detection scheme to control the synchronous rectification switches. A detailed analysis and design of this novel multi-element resonant converter with self-driven synchronous rectification is described. Finally, a DC input voltage of 380-VDC and an output voltage/current of 12-VDC/54-A for the resonant converter prototype is built to verify the theoretical analysis and performance of the proposed converter.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 430
Author(s):  
Chung-Ming Leng ◽  
Huang-Jen Chiu

This paper proposes a single stage alternating current/direct current (AC/DC) flyback converter which contains three output windings with synchronous rectification (SR) function to achieve better cross-regulation and efficiency. Because the three output windings are stacked in a series structure and use synchronous rectification instead of diode rectification, the forward conduction loss of the diode can be eliminated, and the current of each winding can flow bilaterally. Therefore, the energy of leakage inductance can be dissipated through heavy load winding without transient overvoltage in light load winding. Compared with existing methods in the literature, the proposed converter can be realized by simple analog IC with fewer winding turns. Finally, under the extreme load imbalance condition, the cross-regulation is still within ±2.26%. The maximum efficiency of the proposed converter reaches 87%, which is about 3% higher than the conventional Schottky diode solution’s efficiency. The circuit structure and operation principle are described. A practical prototype and experiment results are implemented to verify the feasibility of the proposed converter.


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