In this paper,a novel,separable two-degrees-of-freedom stage with high-precision motion and resolution is proposed for the application of vibration-assisted micromilling.A separable design was realized on the basis of...In this paper,a novel,separable two-degrees-of-freedom stage with high-precision motion and resolution is proposed for the application of vibration-assisted micromilling.A separable design was realized on the basis of the detachable structure of the platform.Flexible stages with different dimensions and types can be utilized in the devices.A circular-fillet hinge is selected as the flexible unit with a parallel structure to realize output decoupling and reduce the coupling error between the two vibration directions.Analytical modeling is conducted to explore the static and dynamic characteristics of the stage.Results reveal a good agreement with the finite element simulation result.A series of experiments were conducted to assess the static and dynamic performances of the flexible stage,encompassing tests such as amplitude response,motion trajectory,and coupling trajectory.The results of these tests revealed that the designed vibration-assisted system exhibits precise movement capabilities.展开更多
静止无功发生器(static var generator,SVG)广泛用于电力系统中解决三相不平衡的问题。采用构造一个无延迟的旋转相量的方法,对静止无功发生器的电流检测部分进行了改进,以解决移相算子带来的延迟导致的误差,提升电流检测的实时性。控...静止无功发生器(static var generator,SVG)广泛用于电力系统中解决三相不平衡的问题。采用构造一个无延迟的旋转相量的方法,对静止无功发生器的电流检测部分进行了改进,以解决移相算子带来的延迟导致的误差,提升电流检测的实时性。控制部分的电流内环采用前馈解耦控制,以解决dq轴上直流变量的耦合问题;由于PI控制系统具有参数难以确定以及难以解决时变复杂系统的缺点,提出了在前馈解耦控制器中使用超螺旋二阶滑模控制的输出电压波形控制方案来代替PI控制。依托这种方法在Matlab中设计出静止无功发生器的模型,对动态三相不平衡负载进行仿真分析。由仿真结果可知,与传统的PI控制相比,此种方法控制效果更好。展开更多
基金This research was supported by Program of Tianjin Science and Technology(No.21ZXJBGX00020)the National Natural Science Foundation of China(Nos.51875404,52175275).
文摘In this paper,a novel,separable two-degrees-of-freedom stage with high-precision motion and resolution is proposed for the application of vibration-assisted micromilling.A separable design was realized on the basis of the detachable structure of the platform.Flexible stages with different dimensions and types can be utilized in the devices.A circular-fillet hinge is selected as the flexible unit with a parallel structure to realize output decoupling and reduce the coupling error between the two vibration directions.Analytical modeling is conducted to explore the static and dynamic characteristics of the stage.Results reveal a good agreement with the finite element simulation result.A series of experiments were conducted to assess the static and dynamic performances of the flexible stage,encompassing tests such as amplitude response,motion trajectory,and coupling trajectory.The results of these tests revealed that the designed vibration-assisted system exhibits precise movement capabilities.
文摘静止无功发生器(static var generator,SVG)广泛用于电力系统中解决三相不平衡的问题。采用构造一个无延迟的旋转相量的方法,对静止无功发生器的电流检测部分进行了改进,以解决移相算子带来的延迟导致的误差,提升电流检测的实时性。控制部分的电流内环采用前馈解耦控制,以解决dq轴上直流变量的耦合问题;由于PI控制系统具有参数难以确定以及难以解决时变复杂系统的缺点,提出了在前馈解耦控制器中使用超螺旋二阶滑模控制的输出电压波形控制方案来代替PI控制。依托这种方法在Matlab中设计出静止无功发生器的模型,对动态三相不平衡负载进行仿真分析。由仿真结果可知,与传统的PI控制相比,此种方法控制效果更好。
