A common method to examine the current-limiting performance of saturated iron-core fault current limiter(SI-FCL) in high-voltage direct-current transmission based on voltage source converter(VSC-HVDC) systems is to so...A common method to examine the current-limiting performance of saturated iron-core fault current limiter(SI-FCL) in high-voltage direct-current transmission based on voltage source converter(VSC-HVDC) systems is to solve differential equations based on the system fault transient characteristics and the equivalent inductance calculation equation. This method analyzes the fault current of the VSC-HVDC system in the time domain. However, it is computationally complex and cannot directly reflect the relationship between parameters and the currentlimiting effect of the SI-FCL.In this paper,the relationship between the magnetic flux density and magnetic field energy of the SI-FCL is analyzed. The energy exchange between the DC capacitor and the SI-FCL in the DC short circuit fault process is analyzed. From the perspective of electromagnetic energy conversion, the criterion for determining the current-limiting ability of the SI-FCL in the transient process is given based on the parameters of the SI-FCL and VSC-HVDC system. On this basis, the characteristics of the DC side fault current and the capacitor voltage when the SI-FCL has current-limiting ability are examined.Based on the parameters of the SI-FCL and VSC-HVDC system, a method for calculating the fault current peak value and capacitor voltage drop time is given. Finally, the accuracy of the analysis of the SI-FCL in the VSC-HVDC system based on the electromagnetic energy conversion mechanism is demonstrated through a case study and simulation results of the VSC-HVDC system with different SI-FCLs.展开更多
A variation-aware task mapping approach is proposed for a multi-core network-on-chips with redundant cores, which includes both the design-time mapping and run-time scheduling algorithms. Firstly, a design-time geneti...A variation-aware task mapping approach is proposed for a multi-core network-on-chips with redundant cores, which includes both the design-time mapping and run-time scheduling algorithms. Firstly, a design-time genetic task mapping algorithm is proposed during the design stage to generate multiple task mapping solutions which cover a maximum range of chips. Then, during the run, one optimal task mapping solution is selected. Additionally, logical cores are mapped to physically available cores. Both core asymmetry and topological changes are considered in the proposed approach. Experimental results show that the performance yield of the proposed approach is 96% on average, and the communication cost, power consumption and peak temperature are all optimized without loss of performance yield.展开更多
对雷达装备故障文本进行智能化分类,有助于提高雷达装备保障效率。针对雷达故障文本专业性强,样本量小且不平衡的问题,通过非核心词EDA进行类内数据增强,以实现在增加文本量的同时保持关键信息不变。针对非核心词EDA方法产生的新样本多...对雷达装备故障文本进行智能化分类,有助于提高雷达装备保障效率。针对雷达故障文本专业性强,样本量小且不平衡的问题,通过非核心词EDA进行类内数据增强,以实现在增加文本量的同时保持关键信息不变。针对非核心词EDA方法产生的新样本多样性不够的问题,增加SSMix(saliency-based span mixup for text classification),进行类间数据增强,通过对输入文本非线性的交叉融合来提升文本的多样性。实验证明,与现有的经典基线分类方法和典型数据增强分类方法相比,该方法在准确率上有较大幅度的提升。展开更多
基金supported in part by the National Key R&D Program of China (No. 2018YFB0904600)in part by the National Nature Science Foundation of China (NSFC) under Grant 51677125
文摘A common method to examine the current-limiting performance of saturated iron-core fault current limiter(SI-FCL) in high-voltage direct-current transmission based on voltage source converter(VSC-HVDC) systems is to solve differential equations based on the system fault transient characteristics and the equivalent inductance calculation equation. This method analyzes the fault current of the VSC-HVDC system in the time domain. However, it is computationally complex and cannot directly reflect the relationship between parameters and the currentlimiting effect of the SI-FCL.In this paper,the relationship between the magnetic flux density and magnetic field energy of the SI-FCL is analyzed. The energy exchange between the DC capacitor and the SI-FCL in the DC short circuit fault process is analyzed. From the perspective of electromagnetic energy conversion, the criterion for determining the current-limiting ability of the SI-FCL in the transient process is given based on the parameters of the SI-FCL and VSC-HVDC system. On this basis, the characteristics of the DC side fault current and the capacitor voltage when the SI-FCL has current-limiting ability are examined.Based on the parameters of the SI-FCL and VSC-HVDC system, a method for calculating the fault current peak value and capacitor voltage drop time is given. Finally, the accuracy of the analysis of the SI-FCL in the VSC-HVDC system based on the electromagnetic energy conversion mechanism is demonstrated through a case study and simulation results of the VSC-HVDC system with different SI-FCLs.
文摘A variation-aware task mapping approach is proposed for a multi-core network-on-chips with redundant cores, which includes both the design-time mapping and run-time scheduling algorithms. Firstly, a design-time genetic task mapping algorithm is proposed during the design stage to generate multiple task mapping solutions which cover a maximum range of chips. Then, during the run, one optimal task mapping solution is selected. Additionally, logical cores are mapped to physically available cores. Both core asymmetry and topological changes are considered in the proposed approach. Experimental results show that the performance yield of the proposed approach is 96% on average, and the communication cost, power consumption and peak temperature are all optimized without loss of performance yield.
文摘对雷达装备故障文本进行智能化分类,有助于提高雷达装备保障效率。针对雷达故障文本专业性强,样本量小且不平衡的问题,通过非核心词EDA进行类内数据增强,以实现在增加文本量的同时保持关键信息不变。针对非核心词EDA方法产生的新样本多样性不够的问题,增加SSMix(saliency-based span mixup for text classification),进行类间数据增强,通过对输入文本非线性的交叉融合来提升文本的多样性。实验证明,与现有的经典基线分类方法和典型数据增强分类方法相比,该方法在准确率上有较大幅度的提升。
