scholarly journals A Comprehensive Overview in Control Algorithms for High Switching-Frequency LLC Resonant Converter

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4455
Author(s):  
Hwa-Pyeong Park ◽  
Mina Kim ◽  
Jee-Hoon Jung

An LLC resonant converter has been widely used in various industrial applications because of its high cost-effectiveness, high power conversion efficiency, simple design methodology, and simple control algorithms using a pulse frequency modulation (PFM). In addition, the soft switching capability of the LLC resonant converter is good to obtain high switching frequency operations, which can get the high-power density of the power converter. Over the past years, several studies have been conducted to improve the performance of a high switching frequency LLC resonant converter with resonant tank design, optimal power stage design, and enhanced control algorithms. This paper is the review paper in terms of the control algorithms for the LLC resonant converter. It focuses on the overview of the high switching-frequency LLC resonant converter in terms of the control algorithms. The advanced control algorithm can improve power conversion efficiency, dynamic performance, tight output voltage regulation, and small electro-magnetic interference. The operational principles of the control algorithms are briefly explained to show their own characteristics and advantages. Thereafter, the research issues for the future works will be discussed in the conclusion.

2019 ◽  
Vol 25 (3) ◽  
pp. 4-9
Author(s):  
Michal Frivaldsky ◽  
Jan Morgos ◽  
Andrej Kanovsky

Dual interleaved LLC resonant converter with half bridge topology of main circuit characterized by high switching frequency (500 kHz), high power density (60 W/inch3) and high efficiency (above 96 %) over entire operational range (20 %–100 %) is described. Focus was given on the practical design of power converter, which will be able to fulfil requirements on wide load range operation characterized by upcoming normative. Since proposed topology is based on dual interleaved LLC converter, the resonant component´s critical tolerance was also investigated to secure reliable and optimal operational point. Consequently, proposals for elimination of intolerance negative impact are also described. The results of theoretical analysis were verified directly through experimental measurements. Experimental results are finally compared with upcoming industrial standard 80 Plus Titanium.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4569
Author(s):  
Vadim Sidorov ◽  
Andrii Chub ◽  
Dmitri Vinnikov

The paper is focused on galvanically isolated series resonant DC–DC converters (SRCs) with a low quality factor of the resonant tank. These converters provide input voltage regulation at fixed switching frequency and good power density. Different modulation methods at the fixed switching frequency enable the implementation of the voltage buck functionality in these converters. The SRC under study is considered as a step-up front-end DC–DC converter for the integration of renewable energy sources in DC microgrids. The paper evaluates the voltage buck performance of the SRC achieved by using different pulse-width modulation (PWM) methods including conventional PWM and shifted PWM. Moreover, the new PWM methods, i.e., the hybrid shifted PWM (HSPWM), improved shifted PWM (ISPWM), and hybrid PWM (HPWM), are proposed to overcome the disadvantages of the existing methods. They improve the power conversion efficiency in the buck mode by reducing the power losses in the semiconductor switches and the isolating transformer of the SRC. The proposed and the existing methods are benchmarked in terms of the components stresses and power conversion efficiency. The presented findings have been experimentally validated by the help of a 200 W prototype, which demonstrated the lowest power loss in the case of the HPWM.


Author(s):  
Minkyu Kyeong ◽  
Jinho Lee ◽  
Matyas Daboczi ◽  
Katherine Stewart ◽  
Huifeng Yao ◽  
...  

Functionalized polyethyleneimines that are compatible with non-fullerene acceptors have been developed by protecting the reactive amine groups, leading to non-fullerene solar cells with high power conversion efficiency and enhanced thermal stability.


Author(s):  
Ritesh Kant Gupta ◽  
Rabindranath Garai ◽  
Maimur Hossain ◽  
Mohammad Adil Afroz ◽  
Dibashmoni Kalita ◽  
...  

Achieving high power conversion efficiency (PCE) polymer solar cells (PSCs) has been very challenging and the ultimate goal for their commercialization. Precise investigation of the active layer morphology and newer...


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