高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此...高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此,针对高速磁浮逆变器并联和串联两种模式,建立NPV偏移模型,得到在调制比和功率因数同时变化时NPV的可控区域。为在全速范围保证NPV平衡,提出一种基于平移调制波的协同控制策略。为减轻整流器功率因数和调制比对NPV的影响,采用一种具有相电压半波对称性的载波脉宽调制,并证明其具备NPV自平衡能力。仿真和硬件在环实验表明,所提策略具有NPV恢复到平衡状态所需时间短、可控范围大等优点,可在高速磁浮全速工况下保证NPV平衡。展开更多
High‐speed maglev trains are subjected to severe dynamic loads,thus posing a failure hazard.It is necessary to account for the vehicle dynamics to improve the structural strength and fatigue life assessment approach ...High‐speed maglev trains are subjected to severe dynamic loads,thus posing a failure hazard.It is necessary to account for the vehicle dynamics to improve the structural strength and fatigue life assessment approach under harsh routes and super high‐speed grades.As the most critical load‐carrying part between the vehicle body and levitation frames,the swing bar was taken as an example to demonstrate the significance of vehicle dynamics to integrate classical structural strength and fatigue life with the service conditions.A multiphysics‐coupled dynamic model of an alpha improvement scheme for an electromagnetic suspension maglev train capable of 600 km/h was established to investigate the complex dynamic loads and fatigue spectra.Using this model,the structural strength and fatigue life of the wrought swing bars were investigated.Results show only a slight effect on the structural strength and fatigue life of swing bars by the super high‐speed grades.The nonaxial bending moments caused by the uncompensated relative displacement between the vehicle body and bolsters are identified as the decisive factors.The minimum safety factor of the structural strength for wrought swing bars is 1.33,while the minimum fatigue life is 34 years.Both match the design requirements but are not conservative enough.Therefore,further verification and optimization are recommended to improve the design of swing bars.展开更多
利用有限元分析与结构优化技术,研究高速磁浮列车复合材料车体部件强度问题。依据复合材料结构和力学特征,建立某高速磁浮列车复合材料车体强度分析模型;基于系统动力学和空气动力学分析结果,确定车体与走行机构之间的接口载荷及车体表...利用有限元分析与结构优化技术,研究高速磁浮列车复合材料车体部件强度问题。依据复合材料结构和力学特征,建立某高速磁浮列车复合材料车体强度分析模型;基于系统动力学和空气动力学分析结果,确定车体与走行机构之间的接口载荷及车体表面承受的气动载荷;运用BS EN 12663:2010标准和Tsai-Wu失效准则对车体结构进行强度分析。结果表明:车体结构强度满足设计要求,其中碳纤维头罩结构的最大Tsai-Wu失效因子仅为0.154;为充分挖掘复合材料的潜能,分别以柔度、质量和铺层顺序为目标函数,对碳纤维头罩进行自由尺寸优化、尺寸优化以及层叠次序优化,最终获得最佳铺层顺序为45°/-45°/0°/90°/90°/0°/45°/-45°/45°/-45°;优化后碳纤维头罩比与优化前质量减轻了28.9%;将优化后的头罩映射到整车车体并进行强度分析,碳纤维头罩的最大Tsai-Wu失效因子为0.163。展开更多
文摘高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此,针对高速磁浮逆变器并联和串联两种模式,建立NPV偏移模型,得到在调制比和功率因数同时变化时NPV的可控区域。为在全速范围保证NPV平衡,提出一种基于平移调制波的协同控制策略。为减轻整流器功率因数和调制比对NPV的影响,采用一种具有相电压半波对称性的载波脉宽调制,并证明其具备NPV自平衡能力。仿真和硬件在环实验表明,所提策略具有NPV恢复到平衡状态所需时间短、可控范围大等优点,可在高速磁浮全速工况下保证NPV平衡。
基金National Key R&D Program of China,Grant/Award Numbers:2016YFB1200602‐15,2016YFB1200602‐17National Natural Science Foundation of China,Grant/Award Numbers:U2032121,12192212Open Research Project of State Key Laboratory of Traction Power,Grant/Award Numbers:2021TPL‐T03,2021TPL‐T04,2021TPL‐T06。
文摘High‐speed maglev trains are subjected to severe dynamic loads,thus posing a failure hazard.It is necessary to account for the vehicle dynamics to improve the structural strength and fatigue life assessment approach under harsh routes and super high‐speed grades.As the most critical load‐carrying part between the vehicle body and levitation frames,the swing bar was taken as an example to demonstrate the significance of vehicle dynamics to integrate classical structural strength and fatigue life with the service conditions.A multiphysics‐coupled dynamic model of an alpha improvement scheme for an electromagnetic suspension maglev train capable of 600 km/h was established to investigate the complex dynamic loads and fatigue spectra.Using this model,the structural strength and fatigue life of the wrought swing bars were investigated.Results show only a slight effect on the structural strength and fatigue life of swing bars by the super high‐speed grades.The nonaxial bending moments caused by the uncompensated relative displacement between the vehicle body and bolsters are identified as the decisive factors.The minimum safety factor of the structural strength for wrought swing bars is 1.33,while the minimum fatigue life is 34 years.Both match the design requirements but are not conservative enough.Therefore,further verification and optimization are recommended to improve the design of swing bars.
文摘利用有限元分析与结构优化技术,研究高速磁浮列车复合材料车体部件强度问题。依据复合材料结构和力学特征,建立某高速磁浮列车复合材料车体强度分析模型;基于系统动力学和空气动力学分析结果,确定车体与走行机构之间的接口载荷及车体表面承受的气动载荷;运用BS EN 12663:2010标准和Tsai-Wu失效准则对车体结构进行强度分析。结果表明:车体结构强度满足设计要求,其中碳纤维头罩结构的最大Tsai-Wu失效因子仅为0.154;为充分挖掘复合材料的潜能,分别以柔度、质量和铺层顺序为目标函数,对碳纤维头罩进行自由尺寸优化、尺寸优化以及层叠次序优化,最终获得最佳铺层顺序为45°/-45°/0°/90°/90°/0°/45°/-45°/45°/-45°;优化后碳纤维头罩比与优化前质量减轻了28.9%;将优化后的头罩映射到整车车体并进行强度分析,碳纤维头罩的最大Tsai-Wu失效因子为0.163。
