The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled...The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.展开更多
In order to obtain digital design of complex mechanical product as optimal as possible in an efficient way,multi- discipline integrated design method is proposed,which integrates multidisciplinary design optimization ...In order to obtain digital design of complex mechanical product as optimal as possible in an efficient way,multi- discipline integrated design method is proposed,which integrates multidisciplinary design optimization (MDO) into digital design process to design virtual prototype (VP) efficiently.Through combining MDO and multi-body system dynamics,MDO integra- tion platform,which takes VP as the core,is constructed.Then automated MDO design of VP is realized and changes of mechani- cal design project can be expressed intuitively during MDO design process.The proposed approach is also demonstrated by using inte- grated analyzing flow of vehicle engineering design.The result shows that the method not only can feasibly realize the MDO of VP, but also can solve the optimization problem of vehicle multi-body system dynamic performance.It can be adopted to the digital de- sign of other complex system.展开更多
A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the con...A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the controller of concurrent design. With the help of the controller of concurrent design, each feature of a part can be designed and evaluated based on manufacturing knowledge and resources, and can be modified according to the results of evaluation. The machining method of design feature can be selected based on manufacturing knowledge. So real time concurrent product and process design can be implemented based on integrated product model that is established based on generalized feature. Products and its design process can be optimized with the help of this system. The information and function integration of product design process can be realized. The time to market and the cost of products can be reduced.展开更多
The traditional power design, construction, has been able to meet the requirements, but it has not been established engineering data database support and the correlation between the data is poor, due to inadequate coo...The traditional power design, construction, has been able to meet the requirements, but it has not been established engineering data database support and the correlation between the data is poor, due to inadequate coordination among design professionals, design easily lead to mistakes, field problems, and design results failed in all aspects of the project to be fully utilized. With the technology of three-dimensional integrated design system penetrates in all walks of life, the introduction of three-dimensional integrated design system substation design solutions and the application of common devices of State Grid Corporation in recent years, which provide technical conditions for the application of virtual reality technology in substation design. According to its own characteristics of substation project, we now propose prospect on virtual reality technology in substation design application.展开更多
为满足训练的信息化需求,设计了灵活通用的数据协议和虚实结合的信息引接系统。基于中间件的分层设计思路,实现了外部信息接收、对内信息转发、通信协议解析与转换、信息对接联调、数据文件记录、配置管理以及信息流量统计等功能;采用了...为满足训练的信息化需求,设计了灵活通用的数据协议和虚实结合的信息引接系统。基于中间件的分层设计思路,实现了外部信息接收、对内信息转发、通信协议解析与转换、信息对接联调、数据文件记录、配置管理以及信息流量统计等功能;采用了MVC软件架构模式,选用Visual Studio 2015作为开发工具,以Oracle数据库作为底层支撑,构建了实装信息及虚拟目标信息接收模块、建立数据映射关系模块、读取数据库方案模块、基础通信接收内部航迹模块、数据包发送模块。实际应用效果表明,该系统能够屏蔽外部装备系统、仿真系统和网络协议之间的差异,提供互联互通,适应虚实结合的训练任务,提高保障能力。该系统具有良好的适应性和可扩展性,可以满足信息化条件下系统的应用和发展需要。展开更多
基金supported by the Tunisian Ministry of High Education and Research under Grant LSE-ENIT-LR11ES15
文摘The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.
基金Funded by the Natural Science Foundation of China(59685003)the Special Fund for Author of Excellent Doctoral Dissertation of China(200232).
文摘In order to obtain digital design of complex mechanical product as optimal as possible in an efficient way,multi- discipline integrated design method is proposed,which integrates multidisciplinary design optimization (MDO) into digital design process to design virtual prototype (VP) efficiently.Through combining MDO and multi-body system dynamics,MDO integra- tion platform,which takes VP as the core,is constructed.Then automated MDO design of VP is realized and changes of mechani- cal design project can be expressed intuitively during MDO design process.The proposed approach is also demonstrated by using inte- grated analyzing flow of vehicle engineering design.The result shows that the method not only can feasibly realize the MDO of VP, but also can solve the optimization problem of vehicle multi-body system dynamic performance.It can be adopted to the digital de- sign of other complex system.
文摘A real time concurrent product and process design system for mechanical parts is described in this paper. It consists of integrated product model, the expert system of product manufacturability evaluation and the controller of concurrent design. With the help of the controller of concurrent design, each feature of a part can be designed and evaluated based on manufacturing knowledge and resources, and can be modified according to the results of evaluation. The machining method of design feature can be selected based on manufacturing knowledge. So real time concurrent product and process design can be implemented based on integrated product model that is established based on generalized feature. Products and its design process can be optimized with the help of this system. The information and function integration of product design process can be realized. The time to market and the cost of products can be reduced.
文摘The traditional power design, construction, has been able to meet the requirements, but it has not been established engineering data database support and the correlation between the data is poor, due to inadequate coordination among design professionals, design easily lead to mistakes, field problems, and design results failed in all aspects of the project to be fully utilized. With the technology of three-dimensional integrated design system penetrates in all walks of life, the introduction of three-dimensional integrated design system substation design solutions and the application of common devices of State Grid Corporation in recent years, which provide technical conditions for the application of virtual reality technology in substation design. According to its own characteristics of substation project, we now propose prospect on virtual reality technology in substation design application.
文摘为满足训练的信息化需求,设计了灵活通用的数据协议和虚实结合的信息引接系统。基于中间件的分层设计思路,实现了外部信息接收、对内信息转发、通信协议解析与转换、信息对接联调、数据文件记录、配置管理以及信息流量统计等功能;采用了MVC软件架构模式,选用Visual Studio 2015作为开发工具,以Oracle数据库作为底层支撑,构建了实装信息及虚拟目标信息接收模块、建立数据映射关系模块、读取数据库方案模块、基础通信接收内部航迹模块、数据包发送模块。实际应用效果表明,该系统能够屏蔽外部装备系统、仿真系统和网络协议之间的差异,提供互联互通,适应虚实结合的训练任务,提高保障能力。该系统具有良好的适应性和可扩展性,可以满足信息化条件下系统的应用和发展需要。
