http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Dan Xiao,Xiaoyan Peng,Xiaopeng Liang,Ying Deng,Guofu Xu,Zhimin Yin 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.3
Hot compression tests of as-homogenized Al-Zn-Mg-Cu alloy were performed at the deformation temperaturerange of 350-450 °C and the strain rate range of 0.001-1 s-1. The Arrhenius-type constitutive equation and theAvrami-type model were established to predict the flow behaviors of the alloy respectively. The processing map atthe true strain of 0.92 was developed to evaluate the workability of the alloy and the related microstructures wereinvestigated. The results show that the Avrami-type model has a higher accuracy to predict flow stress than theArrhenius-type constitutive equation. The stable deformation occurs under high temperature or low strain ratemainly owing to the dynamic recrystallization. Flow instability is prone to occur under the condition of low temperatureand high strain rate due to the initiation and the propagation of micro-cracks. According to the processingmap and corresponding microstructure characteristics, the optimum processing parameters are in the temperaturerange of 380-405 °C and the strain rate range of 0.006-0.035 s-1.
A 5.6 kW 11.7 kW per kg Four-Phase Interleaved Buck Converter for the Unmanned Aerial Vehicle
Cheng Xu-Feng,Peng Zhenzhen,Yang Yulong,Liang Zhimin,Wu Chaofeng,Shao Zhiwei,Wang Dianlong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2
This paper proposed a 5.6 kW 11.7 kW/kg four-phase interleaved buck converter (FPIBC) for the unmanned aerial vehicle (UAV) low-voltage power system. The UAV mainly concerns the lightweight strategy and the power density of the DC-DC converter. We proposed a comprehensive lightweight strategy with the characteristics of reduced inductor current ripples, small size of fi lter inductors and capacitors, and high output power. The output current ripples are reduced by using interleaved modulation strategy and integrated CLC fi lters cascaded to the input side and output side respectively. In addition, the aluminum based printed circuit board (PCB) is used with SMD power transistors to obtain better heat dissipation capability without fans. With abovementioned methods, the designed DC-DC converter has a power of 5.6 kW @ 0.48 kg, the powerto-weight ratio is improved to be 11.7 kW/kg, and the power density is 3 W/cm 3 . The effi ciency of this DC-DC converter is up to 95.8%.