http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Phase-Shift Triple Full-Bridge ZVZCS Converter with All Soft Switched Devices
Zhu, Junjie,Qian, Qinsong,Lu, Shengli,Sun, Weifeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.6
This paper proposes a Phase-Shift Triple Full-Bridge (PSTB) Zero-Voltage Zero-Current-Switching (ZVZCS) converter with a high switching frequency and high efficiency. In the proposed converter, all three bridge legs are shared leading-legs, and all three transformers work in the Discontinuous Conduction Mode (DCM). Thus, all of the switches and diodes in the PSTB ZVZCS can be soft switched. Moreover, since all of the transformers can pass energy from the primary-side to the secondary-side when their primary-side currents are not zero, there is no circulating current. As a result, the PSTB ZVZCS converter can achieve a high efficiency at high operating frequencies. A theoretical analysis and the characteristics of the proposed converter are presented and verified on a 1MHz 200~300V/24V 1.2kW hardware prototype. The proposed converter can reach a peak efficiency of 96.6%.
Phase-Shift Triple Full-Bridge ZVZCS Converter with All Soft Switched Devices
Junjie Zhu,Qinsong Qian,Shengli Lu,Weifeng Sun 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.6
This paper proposes a Phase-Shift Triple Full-Bridge (PSTB) Zero-Voltage Zero-Current-Switching (ZVZCS) converter with a high switching frequency and high efficiency. In the proposed converter, all three bridge legs are shared leading-legs, and all three transformers work in the Discontinuous Conduction Mode (DCM). Thus, all of the switches and diodes in the PSTB ZVZCS can be soft switched. Moreover, since all of the transformers can pass energy from the primary-side to the secondary- side when their primary-side currents are not zero, there is no circulating current. As a result, the PSTB ZVZCS converter can achieve a high efficiency at high operating frequencies. A theoretical analysis and the characteristics of the proposed converter are presented and verified on a 1MHz 200~300V/24V 1.2kW hardware prototype. The proposed converter can reach a peak efficiency of 96.6%.
Zhi Lei,Qinsong Zhu,Yuqing Zhou,Bintao Sun,Weifang Sun,Xiaoming Pan 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.3
Tools are the most vulnerable components in milling processes conducted using numerical control milling machines, and their wear condition directly influences work-product quality and operational safety. As such, tool wear estimation is an essential component of NC milling operations. This study addresses this issue by proposing an extreme learning machine (ELM) method enhanced by a hybrid genetic algorithm and particle swarm optimization (GAPSO) approach for conducting tool wear estimation based on workpiece vibration signals. Here, a few feature parameters in the time, frequency, and time–frequency (Ensemble empirical mode decomposition, EEMD) domains of the workpiece vibration signals are extracted as the input of the ELM model. Then, the initialized weights and thresholds of the ELM model are optimized based on the GAPSO approach with training dataset. Finally, tool wear is estimated using the optimized ELM model with testing dataset. The effectiveness of the proposed method is verified by its application to vibration signals collected from two milling tool wear experiments (an open-access benchmark dataset and a milling tool wear experiment) by comparison to the ELM, GA-ELM, and PSO-ELM methods. The results indicate that the estimation accuracy and optimization efficiency of the proposed method outperforms that of other three methods.
Cu2O Nanoparticles and Multi-Branched Nanowires as Anodes for Lithium-Ion Batteries
Xu Chen,Chunxin Yu,Xiaojiao Guo,Qinsong Bi,Muhammad Sajjad,Yang Ren,Xiaowei Zhou,Zhu Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.09
Novelty Cu2O multi-branched nanowires and nanoparticles with size ranging from ~15 nm to ~60 nm have been synthesized by one-step hydrothermal process. These Cu2O nanostructures when used as anode materials for lithium-ion batteries exhibit the excellent electrochemical cycling stability and reduced polarization during the repeated charge/discharge process. The specific capacity of the Cu2O nanoparticles, multi-branched nanowires and microscale are maintained at 201.2 mAh/g, 259.6mAh/g and 127.4 mAh/g, respectively, under the current density of 0.1 A/g after 50 cycles. The enhanced electrochemical performance of the Cu2O nanostructures compared with microscale counterpart can be attributed to the larger contact area between active Cu2O nanostructures/electrolyte interface, shorter diffusion length of Li+ within nanostructures and the improved stress release upon lithiation/delithiation.