摘要
目的:揭示多场耦合环境下的多自由度系统中柔性结构对机构性能的影响规律,以低压断路器多激励操动机构为例,研究机-电-热-磁耦合的多模态分断性能强化设计方法,提高短路、过载、欠压、缺相和漏电时的瞬时、短延时和长延时分断性能。创新点:1.将多自由度刚柔耦合系统的物理坐标转换为模态坐标,实现模型降阶和关联性能解耦;2.运用类比法获得零部件对关联性能的影响度,通过实验设计将难测属性转化为关联易测量,实现机构的关联性能强化。方法:1.将多自由度的含柔体动力学系统转化为自由度乘模态阶的方阵,通过Craig-Bampton逐层降阶模态矩阵,并由迭代步反馈激活柔体的高阶模态;2.通过类比求解霍尔姆力、洛伦兹力、电动斥力、电磁力和悬臂双金属片激励力,获得多激励系统机构关节的性能关联程度;3.通过低压断路器电气实验和温升实验,验证零件结构柔性对机构的性能影响规律,实现多激励机构多模态分断性能强化设计。结论:1.提出的考虑结构柔性的多激励机构关联性能强化设计方法有助于提高多自由度动力学系统的瞬态性能;2.结构柔性降低分断性能,使高频分断中的峰值段性能退化;3.基于实验设计的电气实验和温升实验,验证了多激励机构关联性能强化方法的有效性。
Multi-actuated rigid-flexible dynamic system exists widely in precision machinery and electrical control fields. The performances, such as kinematic, dynamic, electrical, magnetic, and thermal performances, are correlated and difficult to trap precisely. Therefore, a multi-actuated mechanism design method considering structure flexibility using correlated performance reinforcing is put forward. A system containing flexible subparts with multi degrees of freedom(DOF) with physical coordinate is converted into modal coordinate using ‘DOF×modal order' square matrix. The structure flexibility is described by modal superposition of the shape mode which is considered as additional generalized coordinates. A dynamic equation with large DOF is formulated and reduced based on Craig-Bampton modal truncation. Using analogical design methodology with and without structure flexibility of the low voltage circuit breaker(LVCB), the extent of the performance impact of each subpart is obtained by calculating correlated Holm force, Lorentz force, electrodynamic repulsion force, electromagnetic force, and cantilevered bimetallic strip force. Design of experiments method is employed to reveal the hard-measuring properties using correlated relatively easy-measuring parameters. The trip mechanism is validated by an electrical performance experiment. results show that the structure flexibility can decrease the tripping velocity, which is non-negligible, especially for high frequency tripping. The method provides a reference significance for similar multi-actuated mechanism design.
基金
Project supported by the National Basic Research Program(973 Program) of China(No.2011CB706506)
the National Natural Science Foundation of China(Nos.51221004 and 51375012)
the National High-Tech R&D Program(863 Program) of China(Nos.2013AA041303 and 2013IM030500)
the Zhejiang Provincial Natural Science Foundation of China(No.Y13E050014)
关键词
多激励机构
机-电-热-磁耦合
多体刚柔耦合动力学系统
低压断路器
关联性能强化
Multi-actuated mechanism
Electro-thermal-magnetic mechanism
Multi-body rigid-flexible dynamic system
Low voltage circuit breaker(LVCB)
Correlated performance reinforcing