47 resultados para INDUCTION MOTORS
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
针对异步电机效率优化问题,提出了一种混合搜索方法。该方法起始于模糊自适应搜索,然后切换至黄金分割法以获取确定收敛速度。这样的搜索步骤能够降低转矩波动,避免在最优点附近发生振荡。利用一个包含铁损和机械损耗的异步电机模型,对该方法进行了矢量控制下的性能验证。仿真结果验证了该方法的有效性。
Resumo:
异步电机结构简单、坚固耐用,是主要工业动力设备。异步电机的运行节能问题是工业节能研究的重要内容和热点之一。本文分析了异步电机运行性能,对异步电机的转速和效率检测的非侵入式方法、各种运行方式下的节能控制方法进行了研究,主要贡献有: 对比研究异步电机转速检测的各种方法,采用高分辨率谱估计和混叠采样处理实现了准确的转速检测,给出了转速自动判断方法,为非侵入式效率检测提供了重要的支撑技术。 研究了异步电机的低成本非侵入式效率检测方法,研制了相应的测试装置并进行了相关实验,对检测方法进行精度分析并提出了减小误差的措施。 在非侵入式效率检测的基础上,对于异步电机工频运行、转速开环变频调速和转速闭环转差频率控制变频调速三种运行方式进行了基于效率反馈的节能控制研究。通过专门设计的效率优化模糊控制器实现这三种运行方式下的节能控制,仿真分析表明了所提方法是合理有效的。 针对矢量控制异步电机的效率优化问题,对比分析了模糊搜索和黄金分割法这两种主要效率优化策略的特性,提出了一种混合搜索效率优化方法。这种新方法发挥了前两种寻优策略的互补优势,既保证了收敛的确定性,又降低了对电机输出转矩的影响。仿真分析表明了这种混合搜索方法的可行性。同时,在对输入功率的精确检测条件下,提出了一种全新的效率优化方法,该方法能够在更短时间内实现效率寻优。 探讨了基于无线网络技术的工厂电能管理系统。本文说明了工业无线网络技术的优势,阐述了能够实现系统节能的电能检测与管理技术,如异步电机能效分析模型、异步电机状态监测与预测技术等,分析了基于IEEE802.15.4无线传输协议构建异步电机能效监测系统的可行性。
Resumo:
In this paper, construction of hybrid device by integrating nanowires with F1-ATPase motors is described. The nickel nanowires and multi-segment nanowires, including gold and nickel, were fabricated by electrochemical deposition in nanoporous templates. The nickel nanowires functionalized by biotinylated peptide can be assembled directly onto F1-ATPase motors to act as the propellers. If the multicomponent nanowires, including gold and nickel, were selectively functionalized by the thiol group modified ssDNA and the synthetic peptide, respectively, the biotinylated F1- ATPase motors can be attached to the biotinylated peptide on nickel segment of the nanowires. Then, the multi-component nanowires can also be used as the propellers, and one may observe the rotations of the multi-component nanowires driven by F1-ATPase motors. Therefore, introduction of multiple segments along the length of a nanowire can lead to a variety of multiple chemical functionalities, which can be selectively bound to cells and special biomolecules. This method provides an insight for the construction of other hybrid devices with its controlling arrangement of different biomolecule on designed nanometer scale structures.
Resumo:
A mathematical model is presented for the numerical simulation of the flow, temperature, and concentration fields in an rf plasma chemical reactor. The simulation is performed assuming chemical equilibrium. The extent of validity of this assumption is discussed. The system considered is the reaction of SiCl4 and NH3 for the production of Si3N4.
Resumo:
A kinetic model has been developed for the prediction of the concentration gelds in an rf plasma reactor. A sample calculation for a SiCl4/H2 system is then performed. The model considers the mixing processes along with the kinetics of seven reactions involving the decomposition of these reactants. The results obtained are compared to those assuming chemical equilibrium. The predictions indicate that an equilibrium assumption will result in lower predicted temperature fields in the reactor. Furthermore, for the chemical system considered here, while differences exist between the concentration fields obtained by the two models, the differences are not substantial.
Resumo:
Molecular dynamics (MD) simulation is employed to study the bio-adhesion in F1 ATP molecular motor. Histidine-peptide is widely used as linkage in micro systems because of its strong binding strength to metals. This paper focuses on the adhesion between a synthetic peptide containing 6xHis-tag (Gly-Gly-Lys-Gly-Gly-Lys-Gly-Gly-His-His-His-His-His-His) and metal substrate, which is used to define the position of the F1 ATP molecular motor on the metal substrate. It is shown that the binding strength between histidine and nickel substrate is the strongest, while that of copper is smaller and that of gold substrate is the smallest. From the result of simulation, we find that the stability of adhesion between histidine and the metal substate result of the ringed structure in histidine.
Bifunctional modulating effects of an indigo dimer (bisindigotin) to CYP1A1 induction in H4IIE cells
Induction of defense responses against Alternaria rot by different elicitors in harvested pear fruit