scholarly journals Comparison between Phase-Shift Full-Bridge Converters with Noncoupled and Coupled Current-Doubler Rectifier

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
Cheng-Tao Tsai ◽  
Jye-Chau Su ◽  
Sheng-Yu Tseng
Keyword(s):  
Phase Shift ◽  
High Efficiency ◽  
Load Condition ◽  
Duty Ratio ◽  
The Common ◽  
Step Down ◽  
Efficiency Comparison ◽  
Voltage Conversion ◽  
Study Performance ◽  
Current Ripple

This paper presents comparison between phase-shift full-bridge converters with noncoupled and coupled current-doubler rectifier. In high current capability and high step-down voltage conversion, a phase-shift full-bridge converter with a conventional current-doubler rectifier has the common limitations of extremely low duty ratio and high component stresses. To overcome these limitations, a phase-shift full-bridge converter with a noncoupled current-doubler rectifier (NCDR) or a coupled current-doubler rectifier (CCDR) is, respectively, proposed and implemented. In this study, performance analysis and efficiency obtained from a 500 W phase-shift full-bridge converter with two improved current-doubler rectifiers are presented and compared. From their prototypes, experimental results have verified that the phase-shift full-bridge converter with NCDR has optimal duty ratio, lower component stresses, and output current ripple. In component count and efficiency comparison, CCDR has fewer components and higher efficiency at full load condition. For small size and high efficiency requirements, CCDR is relatively suitable for high step-down voltage and high efficiency applications.

Design and Analysis of a High-Efficiency Two-Phase Interleaved Boost Converter with Modified Conversion Ratio and Low Voltage Stress

2021 ◽  
pp. 2150161
Author(s):  
Mriganka Biswas ◽  
Somanath Majhi ◽  
Harshal Nemade
Keyword(s):  
High Efficiency ◽  
Low Voltage ◽  
Load Condition ◽  
Boost Converter ◽  
Conversion Ratio ◽  
Duty Ratio ◽  
Two Phase ◽  
Voltage Stress ◽  
Interleaved Boost Converter ◽  
In Series

The paper presents a two-phase interleaved boost converter (IBC) providing higher step-up conversion ratio compared to the conventional IBC. The circuit consists of a crossly connected diode-capacitor cell which provides the extra boost up. The two identical capacitors of the cell are charged in parallel and discharged in series providing high voltage gain at considerably low duty ratio. Switching operations, ripple and average currents through inductors are analyzed in continuous conduction mode (CCM). Ripple in input current is also improved. The voltage stress across the semiconductor devices is less in the proposed converter. Also, boundary load condition is derived. Small-signal modeling is carried out and a control circuit is enabled in the voltage mode control framework. Power losses are analyzed and 96.53[Formula: see text] efficiency is achieved. Finally, the proposed converter is designed and implemented, and experimental results are provided.

scholarly journals Power Device Temperature-Balancing Control Method for a Phase-Shift Full-Bridge Converter

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1623
Author(s):  
Jun-Mo Kim ◽  
Jeong Lee ◽  
Kyung Ryu ◽  
Chung-Yuen Won
Keyword(s):  
Phase Shift ◽  
High Efficiency ◽  
Control Method ◽  
Balance Control ◽  
Load Condition ◽  
Power Device ◽  
Maximum Temperature ◽  
Temperature Deviation ◽  
Light Load ◽  
Switching Method

In this paper, a switching method is proposed for power device temperature-balancing in a phase-shift full-bridge (PSFB) converter. PSFB is commonly used for applications that require high efficiency, because a zero-voltage switching (ZVS) operation is possible on the primary-side. In PSFB, the circulation current complicates ZVS under a light-load condition, which generates heat. Meanwhile, the heat generated in PSFB creates a temperature deviation between the lagging leg and the leading leg, which shortens the lifetime of the power device, thereby reducing system reliability and efficiency. To solve this problem, previous studies applied a pulse-width modulation (PWM) switching method for light and medium loads, and a phase-shift switching method for the region where ZVS is possible. Although this method has the advantage of easy control, the maximum temperature of the legs of the PSFB increases with medium loads. In this paper, a temperature-balancing algorithm—a temperature-balance control—is proposed to decrease the leg temperature using switching based on position exchanges of the leading leg and lagging leg along with PWM switching. Temperature-balance control minimizes leg temperature deviation under light load conditions. The proposed control method provides a minimum temperature difference between the two legs and high efficiency.

scholarly journals An Interleaved Phase-Shift Full-Bridge Converter with Dynamic Dead Time Control for Server Power Applications

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 853
Author(s):  
Jia-You Lee ◽  
Jheng-Hung Chen ◽  
Kuo-Yuan Lo
Keyword(s):  
Phase Shift ◽  
High Efficiency ◽  
Dead Time ◽  
Load Condition ◽  
Power Converter ◽  
Switching Loss ◽  
Time Control ◽  
Light Load ◽  
Wide Range ◽  
Voltage Spike

A compact and high-efficiency power converter is the main business of today’s power industry for server power applications. To achieve high efficiency with a low-output ripple, an interleaved phase-shift full-bridge (PSFB) converter is designed, built, and tested for server power applications in this study. In this paper, dynamic dead time control is proposed to reduce the switching loss in the light load condition. The proposed technique reduces the turn-off switching loss and allows a wide range of zero-voltage switching. Moreover, the current ripple of the output inductor can be reduced with the interleaved operation. To verify the theoretical analysis, the proposed PSFB converter is simulated, and a 3 kW prototype is constructed. The experimental results confirm that the conversion efficiency is as high as 97.2% at the rated power of 3 kW and 92.95% at the light load of 300 W. The experimental transient waveforms demonstrated that the voltage spike or drop is less than 2 V in the fast-fluctuating load conditions from 0% load to 60% load and 40% load to 100% load.

Steady State Engine Test Demonstration of Performance Improvement With an Advanced Turbocharger

2013 ◽  
Author(s):  
Harold Sun ◽  
Dave Hanna ◽  
Liangjun Hu ◽  
Eric Curtis ◽  
James Yi ◽  
...  
Keyword(s):  
Steady State ◽  
Performance Improvement ◽  
High Efficiency ◽  
Combustion Engine ◽  
Load Condition ◽  
Department Of Energy ◽  
Speed Ratio ◽  
Mixed Flow ◽  
Turbine Wheel ◽  
Low Speed

Heavy EGR required on diesel engines for future emission regulation compliance has posed a big challenge to conventional turbocharger technology for high efficiency and wide operation range. This study, as part of the U.S. Department of Energy sponsored research program, is focused on advanced turbocharger technologies that can improve turbocharger efficiency on customer driving cycles while extending the operation range significantly, compared to a production turbocharger. The production turbocharger for a medium-duty truck application was selected as a donor turbo. Design optimizations were focused on the compressor impeller and turbine wheel. On the compressor side, advanced impeller design with arbitrary surface can improve the efficiency and surge margin at low end while extending the flow capacity, while a so-called active casing treatment can provide additional operation range extension without compromising compressor efficiency. On the turbine side, mixed flow turbine technology was revisited with renewed interest due to its performance characteristics, i.e. high efficiency at low-speed ratio, relative to the base conventional radial flow turbine, which is relevant to heavy EGR operation for future diesel applications. The engine dynamometer test shows that the advanced turbocharger technology enables over 3% BSFC improvement at part-load as well as full-load condition, in addition to an increase in rated power. The performance improvement demonstrated on engine dynamometer seems to be more than what would typically be translated from the turbocharger flow bench data, indicating that mixed flow turbine may provide additional performance benefits under pulsed exhaust flow on an internal combustion engine and in the low-speed ratio areas that are typically not covered by steady state flow bench tests.

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