Static Random Access Memory(SRAM) based Field Programmable Gate Array(FPGA) is widely applied in the field of aerospace, whose anti-SEU(Single Event Upset) capability becomes more and more important. To improve anti-F...Static Random Access Memory(SRAM) based Field Programmable Gate Array(FPGA) is widely applied in the field of aerospace, whose anti-SEU(Single Event Upset) capability becomes more and more important. To improve anti-FPGA SEU capability, the registers of the circuit netlist are tripled and divided into three categories in this study. By the packing algorithm, the registers of triple modular redundancy are loaded into different configurable logic block. At the same time, the packing algorithm considers the effect of large fan-out nets. The experimental results show that the algorithm successfully realize the packing of the register of Triple Modular Redundancy(TMR). Comparing with Timing Versatile PACKing(TVPACK), the algorithm in this study is able to obtain a 11% reduction of the number of the nets in critical path, and a 12% reduction of the time delay in critical path on average when TMR is not considered. Especially, some critical path delay of circuit can be improved about 33%.展开更多
与常规直流相比,永富直流逆变站存在功率全送和功率分送运行方式,而其处于分网接入方式时电网换相换流器高压直流输电(line commutated converter based high voltage directcurrent,LCC-HVDC)系统的交互振荡模式及特征尚不明确。针对...与常规直流相比,永富直流逆变站存在功率全送和功率分送运行方式,而其处于分网接入方式时电网换相换流器高压直流输电(line commutated converter based high voltage directcurrent,LCC-HVDC)系统的交互振荡模式及特征尚不明确。针对这一特殊运行方式,采用模块化建模的思路建立可以反映系统电气/控制回路间交互耦合路径的运动方程模型。在此基础上,依据系统整流侧-逆变侧、正极-负极间的交互耦合路径分解得到影响系统主导模式稳定性的3条扰动传递路径,即整流侧内部自稳性路径、逆变侧内部自稳性路径、双极交互作用致稳性路径。最后,设置不同工况下的案例,量化评估不同作用路径提供的阻尼大小,并通过仿真验证运动方程模型及扰动传递路径分析结果的正确性,为后续研究分网接入方式下LCC-HVDC系统交互振荡模式的阻尼特征提供模型基础。展开更多
比较航线可更换单元(LRU,line-replaceable unit)与非LRU部件在航线维修时间与成本上的区别,提出一种针对航司的LRU清单优化方法。分析部件故障树(FTA,fault tree analysis),确定故障件及诊断顺序,结合部件3D模型或零件拼装结构数据,推...比较航线可更换单元(LRU,line-replaceable unit)与非LRU部件在航线维修时间与成本上的区别,提出一种针对航司的LRU清单优化方法。分析部件故障树(FTA,fault tree analysis),确定故障件及诊断顺序,结合部件3D模型或零件拼装结构数据,推算含故障诊断流程的拆解路线,使用模特时排法(MODAPTS,modular arrangement of predetermined time standard)对维修任务整体时间进行估算。根据航空公司运营情况,核算维修部件造成的停场损失。针对运营中机型,将该损失与LRU备件成本相比较,判断整体更换LRU是否有利于航空公司节约成本;对设计中的机型,该损失值可指导航空公司向原始设备制造商(OEM,original equipment manufacture)提出设计要求。展开更多
基金Supported by the National Natural Science Foundation of China(No.61106033)
文摘Static Random Access Memory(SRAM) based Field Programmable Gate Array(FPGA) is widely applied in the field of aerospace, whose anti-SEU(Single Event Upset) capability becomes more and more important. To improve anti-FPGA SEU capability, the registers of the circuit netlist are tripled and divided into three categories in this study. By the packing algorithm, the registers of triple modular redundancy are loaded into different configurable logic block. At the same time, the packing algorithm considers the effect of large fan-out nets. The experimental results show that the algorithm successfully realize the packing of the register of Triple Modular Redundancy(TMR). Comparing with Timing Versatile PACKing(TVPACK), the algorithm in this study is able to obtain a 11% reduction of the number of the nets in critical path, and a 12% reduction of the time delay in critical path on average when TMR is not considered. Especially, some critical path delay of circuit can be improved about 33%.
文摘与常规直流相比,永富直流逆变站存在功率全送和功率分送运行方式,而其处于分网接入方式时电网换相换流器高压直流输电(line commutated converter based high voltage directcurrent,LCC-HVDC)系统的交互振荡模式及特征尚不明确。针对这一特殊运行方式,采用模块化建模的思路建立可以反映系统电气/控制回路间交互耦合路径的运动方程模型。在此基础上,依据系统整流侧-逆变侧、正极-负极间的交互耦合路径分解得到影响系统主导模式稳定性的3条扰动传递路径,即整流侧内部自稳性路径、逆变侧内部自稳性路径、双极交互作用致稳性路径。最后,设置不同工况下的案例,量化评估不同作用路径提供的阻尼大小,并通过仿真验证运动方程模型及扰动传递路径分析结果的正确性,为后续研究分网接入方式下LCC-HVDC系统交互振荡模式的阻尼特征提供模型基础。
文摘比较航线可更换单元(LRU,line-replaceable unit)与非LRU部件在航线维修时间与成本上的区别,提出一种针对航司的LRU清单优化方法。分析部件故障树(FTA,fault tree analysis),确定故障件及诊断顺序,结合部件3D模型或零件拼装结构数据,推算含故障诊断流程的拆解路线,使用模特时排法(MODAPTS,modular arrangement of predetermined time standard)对维修任务整体时间进行估算。根据航空公司运营情况,核算维修部件造成的停场损失。针对运营中机型,将该损失与LRU备件成本相比较,判断整体更换LRU是否有利于航空公司节约成本;对设计中的机型,该损失值可指导航空公司向原始设备制造商(OEM,original equipment manufacture)提出设计要求。
