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A line-voltage-sensorless synchronous rectifier 总被引:3,自引:0,他引:3
Bong-Hwan Kwon Jang-Hyoun Youm Jee-Woo Lim 《Power Electronics, IEEE Transactions on》1999,14(5):966-972
A line-voltage-sensorless control for three-phase pulsewidth-modulated (PWM) synchronous rectifiers is presented. A line synchronization and unity power factor control are described. Indirect synchronization without sensing the line voltage allows a standard vector-controlled inverter to be used as a synchronous rectifier without requiring any additional hardware. Furthermore, the line synchronization can be properly operated under line voltage distortion or notching and line frequency variation. All control functions are implemented with a single-chip microcontroller. It is shown via experimental results that the proposed controller gives good performance for the synchronous rectifier 相似文献
86.
提出了一种基于黄金分割法和二分法寻查思想的一维积分来实现二维积分的方法,此方法能迅速而精确地计算RTD电流密度-电压曲线适用于RTD及其电路的计算机辅助设计。 相似文献
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从接口定义语言( I D L)、对象请求代理( O R B)、对象服务等几个方面对公共对象请求代理( C O R B A)体系结构参考模型进行了概括的分析和描述,并对 C O R B A 与因特网、 W W W 应用相结合后的三层结构模型进行了说明。 相似文献
89.
A first‐principles‐based effective Hamiltonian is developed and employed to investigate finite‐temperature structural properties of a prototype of perovskite halides, that is CsPbI3. Such simulations, when using first‐principles‐extracted coefficients, successfully reproduce the existence of an orthorhombic Pnma state and its iodine octahedral tilting angles around room temperature. However, they also yield a direct transformation from Pnma to cubic upon heating, unlike measurements that reported the occurrence of an intermediate long‐range‐tilted tetragonal P4/mbm phase in‐between the orthorhombic and cubic phases. Such disagreement, which may cast some doubts about the extent to which first‐principle methods can be trusted to mimic hybrid perovskites, can be resolved by “only” changing one short‐range tilting parameter in the whole set of effective Hamiltonian coefficients. In such a case, some reasonable values of this specific parameter result in the predictions that i) the intermediate P4/mbm state originates from fluctuations over many different tilted states; and ii) the cubic phase is highly locally distorted and develops strong transverse antiphase correlation between first‐nearest neighbor iodine octahedral tiltings, before undergoing a phase transition to P4/mbm under cooling. 相似文献
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Shu Gong Lim Wei Yap Yi Zhu Bowen Zhu Yan Wang Yunzhi Ling Yunmeng Zhao Tiance An Yuerui Lu Wenlong Cheng 《Advanced functional materials》2020,30(25)
An artificial basilar membrane (ABM) is an acoustic transducer that mimics the mechanical frequency selectivity of the real basilar membrane, which has the potential to revolutionize current cochlear implant technology. While such ABMs can be potentially realized using piezoelectric, triboelectric, and capacitive transduction methods, it remains notoriously difficult to achieve resistive ABM due to the poor frequency discrimination of resistive‐type materials. Here, a point crack technology on noncracking vertically aligned gold nanowire (V‐AuNW) films is reported, which allows for designing soft acoustic sensors with electric signals in good agreement with vibrometer output—a capability not achieved with corresponding bulk cracking system. The strategy can lead to soft microphones for music recognition comparable to the conventional microphone. Moreover, a soft resistive ABM is demonstrated by integrating eight nanowire‐based sensor strips on a soft trapezoid frame. The wearable ABM exhibits high‐frequency selectivity in the range of 319–1951 Hz and high sensitivity of 0.48–4.26 Pa?1. The simple yet efficient fabrication in conjunction with programmable crack design indicates the promise of the methodology for a wide range of applications in future wearable voice recognition devices, cochlea implants, and human–machine interfaces. 相似文献