近年来,高比例可再生能源发电接入我国电网,通过多条特高压/超高压交直流输电线路实现远距离传输,电网对故障后的暂态电压过程更加敏感,暂态电压安全成为我国电网的核心威胁之一。这已经成为国内外学术界和产业界关注的热点,其中一个焦...近年来,高比例可再生能源发电接入我国电网,通过多条特高压/超高压交直流输电线路实现远距离传输,电网对故障后的暂态电压过程更加敏感,暂态电压安全成为我国电网的核心威胁之一。这已经成为国内外学术界和产业界关注的热点,其中一个焦点是如何通过有效的控制手段降低出现暂态电压不安全的风险。该文设计并研发了面向高比例可再生能源交直流混联电网的动态自动电压控制(dynamic automatic voltage control,DAVC)系统,通过考虑在线预想故障集的预防控制,提升电网故障后的暂态电压支撑能力。阐述了所研制的DAVC系统总体结构、主要功能和系统设计,通过在实际大型电网的应用案例说明其效果。目前,该DAVC系统已经在我国多个网省级电网调度控制中心取得实际在线应用。展开更多
IEEE PES 2006年度学术会议和国际大电网会议(CIGRE)2006基本上代表了当今电力技术的最高水平和最新研究方向,其论文集对我国电力系统运行和科研工作有较高的参考价值。本文对上述2个会议的论文集进行了综述,主要内容包括动态安全评估...IEEE PES 2006年度学术会议和国际大电网会议(CIGRE)2006基本上代表了当今电力技术的最高水平和最新研究方向,其论文集对我国电力系统运行和科研工作有较高的参考价值。本文对上述2个会议的论文集进行了综述,主要内容包括动态安全评估、广域量测系统、广域控制系统、系统恢复等方面的研究现状介绍与经验总结。最后结合我国电力系统调度自动化方面的实际情况提出了一些建议。展开更多
Various control systems for a robotic excavator named LUCIE (Lancaster University Computerized and Intelligent Excavator),were investigated. The excavator is being developed to dig trenches autonomously. One stumbling...Various control systems for a robotic excavator named LUCIE (Lancaster University Computerized and Intelligent Excavator),were investigated. The excavator is being developed to dig trenches autonomously. One stumbling block is the achievement of adequate,accurate,quick and smooth movement under automatic control. Here,both classical and modern approaches are considered,including proportional-integral-derivative (PID) control tuned by conventional Zigler-Nichols rules,linear proportional-integral-plus (PIP) control,and a novel nonlinear PIP controller based on a state-dependent parameter (SDP) model structure,in which the parameters are functionally dependent on other variables in the system. Implementation results for the excavator joint arms control demonstrate that SDP-PIP controller provides the improved performance with fast,smooth and accurate response in comparison with both PID and linearized PIP control.展开更多
Using hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle as a simulation example, the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle were simulated and disc...Using hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle as a simulation example, the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle were simulated and discussed with SIMULINK software and hydraulic control theory. The results show that the dynamic characteristics of hydraulic power steering system are improved obviously by using bladder accumulator, the hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle generates vibration at the initial stage under the normal steering condition of pulse input, and its static response time is 0.25 s shorter than that without bladder accumulator. Under the normal steering working condition, the capacity of steering accumulator for absorbing pulse is directly proportional to the cross section area of connecting pipeline, and inversely proportional to the length of connecting pipeline. At the same time, the precharge pressure of nitrogen in steering accumulator should be 60%80% of the rated minimum working pressure of hydraulic power steering system. Under the abnormal steering working condition, the steering cylinder piston may obtain higher motion velocity, and the dynamic response velocity of hydraulic power steering system can be increased by reducing the pressure drop of hydraulic pipelines between the accumulator and steering cylinder and by increasing the rated pressure of hydraulic power steering system, but the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle have nothing to do with the precharge pressure of nitrogen in steering accumulator.展开更多
A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Compar...A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Comparing with the traditional backstepping method that has ＂explosion of terms＂ problem, the new proposed control system is a combination of the dynamic surface control technique and the backstepping. The dynamic surface control （DSC） technique can resolve the ＂explosion of terms＂ problem that is caused by differential coefficient calculation in the model, and the problem can bring a complexity that will cause the backstepping method hardly to be applied to the practical application, especially to the multi-joint robot. Finally, the validity of the method was proved in the laboratory environment that was set up on the 5-DOF （degree of freedom） flexible joint robot. Tracking errors of DSC-backstepping impedance control that were 2.0 and 1.5 mm are better than those of backstepping impedance control which were 3.5 and 2.5 mm in directions X, Y in free space, respectively. And the anticipant Cartesian impedance behavior and compliant behavior were nchieved successfully as depicted theoretically.展开更多
文摘近年来,高比例可再生能源发电接入我国电网,通过多条特高压/超高压交直流输电线路实现远距离传输,电网对故障后的暂态电压过程更加敏感,暂态电压安全成为我国电网的核心威胁之一。这已经成为国内外学术界和产业界关注的热点,其中一个焦点是如何通过有效的控制手段降低出现暂态电压不安全的风险。该文设计并研发了面向高比例可再生能源交直流混联电网的动态自动电压控制(dynamic automatic voltage control,DAVC)系统,通过考虑在线预想故障集的预防控制,提升电网故障后的暂态电压支撑能力。阐述了所研制的DAVC系统总体结构、主要功能和系统设计,通过在实际大型电网的应用案例说明其效果。目前,该DAVC系统已经在我国多个网省级电网调度控制中心取得实际在线应用。
文摘IEEE PES 2006年度学术会议和国际大电网会议(CIGRE)2006基本上代表了当今电力技术的最高水平和最新研究方向,其论文集对我国电力系统运行和科研工作有较高的参考价值。本文对上述2个会议的论文集进行了综述,主要内容包括动态安全评估、广域量测系统、广域控制系统、系统恢复等方面的研究现状介绍与经验总结。最后结合我国电力系统调度自动化方面的实际情况提出了一些建议。
基金Work supported by the Lancaster University,UK and Jiangsu Provincial Laboratory of Advanced Robotics,SooChow University,ChinaProject(BK2009509) supported by the Natural Science Foundation of Jiangsu Province,China+1 种基金Project(K5117827) supported by the Scientific Research Foundation for the Returned Scholars,Ministry of Education of ChinaProject(Q3117918) supported by the Scientific Research Foundation for Young Teachers of Soochow University,China
文摘Various control systems for a robotic excavator named LUCIE (Lancaster University Computerized and Intelligent Excavator),were investigated. The excavator is being developed to dig trenches autonomously. One stumbling block is the achievement of adequate,accurate,quick and smooth movement under automatic control. Here,both classical and modern approaches are considered,including proportional-integral-derivative (PID) control tuned by conventional Zigler-Nichols rules,linear proportional-integral-plus (PIP) control,and a novel nonlinear PIP controller based on a state-dependent parameter (SDP) model structure,in which the parameters are functionally dependent on other variables in the system. Implementation results for the excavator joint arms control demonstrate that SDP-PIP controller provides the improved performance with fast,smooth and accurate response in comparison with both PID and linearized PIP control.
文摘Using hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle as a simulation example, the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle were simulated and discussed with SIMULINK software and hydraulic control theory. The results show that the dynamic characteristics of hydraulic power steering system are improved obviously by using bladder accumulator, the hydraulic power steering system of model EIMCO 922 load-haul-dump vehicle generates vibration at the initial stage under the normal steering condition of pulse input, and its static response time is 0.25 s shorter than that without bladder accumulator. Under the normal steering working condition, the capacity of steering accumulator for absorbing pulse is directly proportional to the cross section area of connecting pipeline, and inversely proportional to the length of connecting pipeline. At the same time, the precharge pressure of nitrogen in steering accumulator should be 60%80% of the rated minimum working pressure of hydraulic power steering system. Under the abnormal steering working condition, the steering cylinder piston may obtain higher motion velocity, and the dynamic response velocity of hydraulic power steering system can be increased by reducing the pressure drop of hydraulic pipelines between the accumulator and steering cylinder and by increasing the rated pressure of hydraulic power steering system, but the dynamic characteristics of hydraulic power steering system in load-haul-dump vehicle have nothing to do with the precharge pressure of nitrogen in steering accumulator.
基金Project(2006AA04Z228) supported by the National High-Tech Research and Development Program of ChinaProject(PCSIRT) supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Comparing with the traditional backstepping method that has ＂explosion of terms＂ problem, the new proposed control system is a combination of the dynamic surface control technique and the backstepping. The dynamic surface control （DSC） technique can resolve the ＂explosion of terms＂ problem that is caused by differential coefficient calculation in the model, and the problem can bring a complexity that will cause the backstepping method hardly to be applied to the practical application, especially to the multi-joint robot. Finally, the validity of the method was proved in the laboratory environment that was set up on the 5-DOF （degree of freedom） flexible joint robot. Tracking errors of DSC-backstepping impedance control that were 2.0 and 1.5 mm are better than those of backstepping impedance control which were 3.5 and 2.5 mm in directions X, Y in free space, respectively. And the anticipant Cartesian impedance behavior and compliant behavior were nchieved successfully as depicted theoretically.
