Innovations for electric vehicles have advanced quickly in latest decades. Large-scale business use of these vehicles is still constrained by reliability-related issues. By utilising fault tree (FT) and Monte Carlo si...Innovations for electric vehicles have advanced quickly in latest decades. Large-scale business use of these vehicles is still constrained by reliability-related issues. By utilising fault tree (FT) and Monte Carlo simulation, a mathematical prototype is created that includes the reliability traits of all major electrical parts of the vehicle system, including the battery, motor, drive, controllers. The research demonstrates that by raising the component restoration rates, the vehicle’s survivability can be raised. A thorough discussion of this paradigm is provided, along with a presentation and analysis of the reliability estimations based on an electric vehicle. This research on the reliability design and maintenance of an electric vehicle can be supported by the ideas that are outlined in the paper. Additionally, the findings of this study may be helpful to those who build electric vehicle, especially when upgrading the components efficiency and planning for reliability increase.展开更多
In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory w...In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory was employed and combined with conventional FTA method. The basic events failure probabilities were described by interval numbers,and the interval operators of logical gates in FTA were deduced based on interval theory. Finally,the reliability assessment of excavator variable-frequency speed control system was done by interval FTA method. The result shows that the interval FTA method is suitable for the complex system with insufficient failure data.展开更多
Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distingui...Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.展开更多
The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were prop...The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were proposed to use together with rapid digital protection against short-circuit regimes in transformer windings. This paper presents an application’s experience of LVI-testing, some results of the use of Frequency Response Analysis (FRA) to check the condition of transformer windings and infra-red control results of electrical equipment. The LVI method and short-circuit inductive reactance measurements are sensitive for detecting such faults as radial, axial winding deformations, a twisting of low-voltage or regulating winding, a losing of winding’s pressing and others.展开更多
动力电池是电动化飞行得以实现的重要组成部分,其技术层次和安全水准对电动垂直起降飞行器(Electric Vertical Take off and Landing aircraft,eVTOL)的商业化推广尤为重要。本文在典型飞行任务下,研究电池性能对eVTOL飞行器的运营性能...动力电池是电动化飞行得以实现的重要组成部分,其技术层次和安全水准对电动垂直起降飞行器(Electric Vertical Take off and Landing aircraft,eVTOL)的商业化推广尤为重要。本文在典型飞行任务下,研究电池性能对eVTOL飞行器的运营性能、适航性能和安全性能的影响。利用开源软件SUAVE(Stanford University Aerospace Vehicle Environment,SUAVE)对复合翼eVTOL进行了整机与动力总成的建模,利用故障树分析(Fault Tree analysis,FTA)方法对动力总成进行了安全性分析。通过仿真,发现在现有电池技术水平下,电池的放电倍率约束是决定电池性能需求的关键限制条件,针对本文设计的eVTOL,372 Wh/kg是满足所有安全约束的最低能量密度,在使用过程中电池容量的衰退是设计者选择电池能量密度的重要参考指标。单独改善电池的可靠性对动力总成可靠性的提升是有限的,但电池性能的衰退将使电池成为动力总成失效的主要因素。通过FTA发现本文搭建的典型动力总成失效率为1.524×10^(-7),接近SC-VTOL-01中单座飞行器的基础级灾难性故障率要求。展开更多
在电力通信网络的实际运行过程中,故障处理工作的质量是影响其运行质量的重要因素,相关人员只有充分了解各种常见故障,才能在短时间内锁定和识别故障,并采取针对性的处理措施。为了快速且准确地处理各种电力通信传输网络常见故障,文章...在电力通信网络的实际运行过程中,故障处理工作的质量是影响其运行质量的重要因素,相关人员只有充分了解各种常见故障,才能在短时间内锁定和识别故障,并采取针对性的处理措施。为了快速且准确地处理各种电力通信传输网络常见故障,文章使用文献研究法和经验分析法研究电力通信传输网络常见故障和处理方法。针对电力通信传输网络中再生段信号丢失告警、准同步数字系列(Plesiochronous Digital Hierarchy,PDH)输入信号丢失告警、支路单元告警指示信号、复用段信号劣化告警等常见故障,需要结合实际情况采取有针对性的处理措施。展开更多
In this paper, we adopt a novel applied approach to fault analysis based on data mining theory. In our researches, global information will be introduced into the electric power system, we are using mainly cluster anal...In this paper, we adopt a novel applied approach to fault analysis based on data mining theory. In our researches, global information will be introduced into the electric power system, we are using mainly cluster analysis technology of data mining theory to resolve quickly and exactly detection of fault components and fault sections, and finally accomplish fault analysis. The main technical contributions and innovations in this paper include, introducing global information into electrical engineering, developing a new application to fault analysis in electrical engineering. Data mining theory is defined as the process of automatically extracting valid, novel, potentially useful and ultimately comprehensive information from large databases. It has been widely utilized in both academic and applied scientific researches in which the data sets are generated by experiments. Data mining theory will contribute a lot in the study of electrical engineering.展开更多
文摘Innovations for electric vehicles have advanced quickly in latest decades. Large-scale business use of these vehicles is still constrained by reliability-related issues. By utilising fault tree (FT) and Monte Carlo simulation, a mathematical prototype is created that includes the reliability traits of all major electrical parts of the vehicle system, including the battery, motor, drive, controllers. The research demonstrates that by raising the component restoration rates, the vehicle’s survivability can be raised. A thorough discussion of this paradigm is provided, along with a presentation and analysis of the reliability estimations based on an electric vehicle. This research on the reliability design and maintenance of an electric vehicle can be supported by the ideas that are outlined in the paper. Additionally, the findings of this study may be helpful to those who build electric vehicle, especially when upgrading the components efficiency and planning for reliability increase.
基金National High-Tech Research and Development Program(863 Program),China(No.2012AA062001)
文摘In consideration of the uncertainty of basic events failure rate and lack of probability statistical information in fault tree analysis( FTA) of excavator variable-frequency speed control system, the interval theory was employed and combined with conventional FTA method. The basic events failure probabilities were described by interval numbers,and the interval operators of logical gates in FTA were deduced based on interval theory. Finally,the reliability assessment of excavator variable-frequency speed control system was done by interval FTA method. The result shows that the interval FTA method is suitable for the complex system with insufficient failure data.
文摘Smart grid was proposed as a practical form of future power distribution system. Evaluating the reliability of smart grids was of great importance and significance. A revised fault tree model was proposed to distinguish and separate grid-connected operation mode and islanded operation mode of smart grids,focusing on the perspective of the consumers. A hierarchical Monte Carlo simulation method for reliability evaluation was also proposed based on the proposed fault tree model. A case of reliability evaluation for the future renewable electric energy delivery and management( FREEDM) system was carried out and analyzed. The proposed methods can be applicable to other forms of smart grids.
文摘The most important elements of “intellectual networks” (Smart Grid) are the systems of monitoring the parameters of electrical equipment. Information-measuring systems (IMS), which described in this paper, were proposed to use together with rapid digital protection against short-circuit regimes in transformer windings. This paper presents an application’s experience of LVI-testing, some results of the use of Frequency Response Analysis (FRA) to check the condition of transformer windings and infra-red control results of electrical equipment. The LVI method and short-circuit inductive reactance measurements are sensitive for detecting such faults as radial, axial winding deformations, a twisting of low-voltage or regulating winding, a losing of winding’s pressing and others.
文摘动力电池是电动化飞行得以实现的重要组成部分,其技术层次和安全水准对电动垂直起降飞行器(Electric Vertical Take off and Landing aircraft,eVTOL)的商业化推广尤为重要。本文在典型飞行任务下,研究电池性能对eVTOL飞行器的运营性能、适航性能和安全性能的影响。利用开源软件SUAVE(Stanford University Aerospace Vehicle Environment,SUAVE)对复合翼eVTOL进行了整机与动力总成的建模,利用故障树分析(Fault Tree analysis,FTA)方法对动力总成进行了安全性分析。通过仿真,发现在现有电池技术水平下,电池的放电倍率约束是决定电池性能需求的关键限制条件,针对本文设计的eVTOL,372 Wh/kg是满足所有安全约束的最低能量密度,在使用过程中电池容量的衰退是设计者选择电池能量密度的重要参考指标。单独改善电池的可靠性对动力总成可靠性的提升是有限的,但电池性能的衰退将使电池成为动力总成失效的主要因素。通过FTA发现本文搭建的典型动力总成失效率为1.524×10^(-7),接近SC-VTOL-01中单座飞行器的基础级灾难性故障率要求。
文摘在电力通信网络的实际运行过程中,故障处理工作的质量是影响其运行质量的重要因素,相关人员只有充分了解各种常见故障,才能在短时间内锁定和识别故障,并采取针对性的处理措施。为了快速且准确地处理各种电力通信传输网络常见故障,文章使用文献研究法和经验分析法研究电力通信传输网络常见故障和处理方法。针对电力通信传输网络中再生段信号丢失告警、准同步数字系列(Plesiochronous Digital Hierarchy,PDH)输入信号丢失告警、支路单元告警指示信号、复用段信号劣化告警等常见故障,需要结合实际情况采取有针对性的处理措施。
文摘In this paper, we adopt a novel applied approach to fault analysis based on data mining theory. In our researches, global information will be introduced into the electric power system, we are using mainly cluster analysis technology of data mining theory to resolve quickly and exactly detection of fault components and fault sections, and finally accomplish fault analysis. The main technical contributions and innovations in this paper include, introducing global information into electrical engineering, developing a new application to fault analysis in electrical engineering. Data mining theory is defined as the process of automatically extracting valid, novel, potentially useful and ultimately comprehensive information from large databases. It has been widely utilized in both academic and applied scientific researches in which the data sets are generated by experiments. Data mining theory will contribute a lot in the study of electrical engineering.
