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采用端口阻抗测试的车载充电机传导电磁干扰建模方法研究

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西安交通大学学报 2025年第1期59卷 172-182页

作者：李季风耿宇宇贾晋廖兴林路青洋重庆理工大学电气与电子工程学院重庆400054 重庆理工大学汽车零部件先进制造技术教育部重点实验室重庆400054

针对电动汽车车载充电机的设计过程中普遍存在的电磁干扰频率范围广、干扰源复杂的问题,提出了一种基于端口阻抗测试的等效电路建模和系统级协同仿真方法。首先,通过对车载充电机系统各部件进行阻抗测试和三维电磁仿真,建立了无源器件... 详细信息

针对电动汽车车载充电机的设计过程中普遍存在的电磁干扰频率范围广、干扰源复杂的问题,提出了一种基于端口阻抗测试的等效电路建模和系统级协同仿真方法。首先,通过对车载充电机系统各部件进行阻抗测试和三维电磁仿真,建立了无源器件、端口滤波器和高压屏蔽线缆模型,提取了系统印制电路板关键回路的高频寄生参数。其次,建立了有源器件的仿真电路模拟器等效模型,并通过双脉冲实验验证模型的精度;针对功率因数校正电路控制环节的仿真与建模难以同步实现的问题,采用协同建模的方法构建整个系统的等效电路模型。最后,将各部件模型组合在一起,建立了完整的车载充电机系统传导电磁干扰预测模型,并依据相关测试标准进行了系统传导电磁干扰仿真和实验。结果表明:在150 kHz~30 MHz频率范围内,预测结果与实际结果的误差小于9 dB,具有良好的一致性,表明该模型能够精确预测车载充电机系统高压交流端的传导干扰水平,可以有效指导充电机系统的电磁兼容正向设计。

关键词：车载充电机电磁干扰端口阻抗测试协同仿真

RANDOM CONTINUOUS MODEL OF SCALE-FREE NETWORKS

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Journal of Systems Science & Complexity 2011年第2期24卷 218-224页

作者： Xianmin geng College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China.

There are a lot of continuous evolving networks in real world, such as Internet, WWW network, etc. The evolving operation of these networks are not an equating interval of time by chance. In this paper, the author proposes a new mathematical model for the mechanism of continuous single preferential attachment on the scale free networks, and counts the distribution of degree using stochastic analysis. Namely, the author has established the random continuous model of the network evolution of which counting process determines the operating number, and has proved that this system self-organizes into scale-free structures with scaling exponent γ=3＋a/m.

关键词： Counting processes degree distribution scaling exponent scale-free networks.

Probability-based method using RFEM for predicting wall deflection caused by excavation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第10期12卷 737-746页

作者： Yu-geng TANG Department of Architecture Hwa-Hsia Institute of Technology Taiwan 23568 Taipei

This study employs the random finite element method (RFEM) to analyze the wall deflection caused by excavation. The RFEM combined random fields of material properties with the FEM through the Monte Carlo simulation. A well-documented excavation case history is employed to evaluate the influence of uncertainty of analysis parameters. This study shows that RFEM can provide reasonable estimations of the exceedance probability of wall deflection caused by excavation, and has the potential to be a useful tool to account for the uncertainties of material and model parameters in the numerical analysis.

关键词： Excavation Random finite element method (RFEM) Uncertainty Wall deflection

EFFECTS　OF　TEMPERATURE　TREATMENT　ON　MICROSTRUCTURE　AND　PROPERTIES　OF　ZA27　ALLOY

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中国有色金属学会会刊：英文版 1995年第3期5卷 113-118页

作者： geng, Haoran geng, Guili Gao, Xiqi Ma, Jiaji Shandong Polytechnic Univ Jinan China

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ＥＦＦＥＣＴＳＯＦＴＥＭＰＥＲＡＴＵＲＥＴＲＥＡＴＭＥＮＴＯＮＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＺＡ２７ＡＬＬＯＹ￥Ｇｅｎｇ，Ｈａｏｒａｎ；Ｇｅｎｇ，Ｇｕｉｌｉ；Ｇａｏ，Ｘｉｑｉ；Ｍａ，Ｊｉａｊｉ（ＤｅｐａｒｔｍｅｎｔｏｆＭａ...

关键词： ZA27 alloy high-Al Zn-based alloy thermal-rate treatment of melt

Partial-TMR: A New Method for Protecting Register Files Against Soft Error Based on Lifetime Analysis

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Journal of Computer Science & Technology 2021年第5期36卷 1089-1101页

作者： Xian-geng Liang Ying-Ke Gao geng-Xin Hua Beijing Institute of Control Engineering China Academy of Space TechnologyBeijing 100090China

High-energy particles in the space can easily cause soft error in register file(RF).As a critical structure in a processor,RF often stores data for long periods of time and is read frequently,resulting in a higher probability of spreading corrupted data to other parts of the *** triple modular redundancy(TMR)is a common and effective fault tolerance method that enables multi-bit error *** full TMR for all the registers could cause excessive area and power ***,some registers in RF have less impact on processor ***,there is no need to design TMR for *** paper designs an efficient strategy which can rate the registers in RF based on their *** on the proposed strategy,a new RF fault tolerance method named Partial-TMR formulates in this paper,which selectively protects more vulnerable registers against multi-bit error,and improves fault tolerance *** integer RF,Partial-TMR improves its soft error correction capability by 24.5%relative to the baseline system and 3%relative to ParShield,while for floating-point RF,the improvement comes to 5.17%and 0.58%*** soft error correction capability of Partial-TMR is slightly lower than that of full TMR by 1%to 3%,but Partial-TMR significantly cuts the area and power *** with full TMR,Partial-TMR decreases the area and power overheads by 71.6%and 64.9%,*** also has little impact on the ***-TMR is a more cost-effective fault tolerance method compared with ParShield and full TMR.

关键词： register file soft error lifetime analysis selective protection triple modular redundancy(TMR)

Fault ride-through of renewable energy conversion systems during voltage recovery

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Journal of Modern Power Systems and Clean Energy 2016年第1期4卷 28-39页

作者： Ruiqi LI Hua geng geng YANG Department of Automation Tsinghua UniversityBeijing 100084China

Asymmetrical voltage swells during recovery of a short-circuit fault lead to fluctuations in the dc-link voltage of a renewable energy conversion system(RECS),and may induce reversed power flow and even trip the RECS. This paper studies characteristics of both typical causes resulting in the practical asymmetrical voltage swell and the voltage at the point of common coupling(PCC)during the fault recovery. As analyzed, the fault recovery process can be divided into two continuous periods in which different control strategies have to be applied. Also protective measures are necessary in the transient period of the process. Additionally, the asymmetrical high-voltage ride-through capability and the controllability criteria of the RECS are analyzed based on eliminating the fluctuations. Furthermore, an asymmetrical control scheme is proposed to maintain the controllability of the RECS and ride through the entire recovery process. As verified by the simulation, the scheme can promise the RECS to deal with the practical fault recovery period and mitigate the dc-link voltage fluctuations, which improves the reliability of the RECS and the power system.

关键词： Inverter Renewable energy conversion system Asymmetrical grid voltage High-voltage ride-through(HVRT) Limit analysis

Randomized difference-based gradient-free algorithm for distributed resource allocation

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Science China(Information Sciences) 2022年第4期65卷 212-228页

作者： Xiaoxue geng Wenxiao ZHAO Key Laboratory of Systems and Control Institute of Systems Science Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

This paper considers a distributed resource allocation problem over time-varying networks. The objective of each agent in the network is to optimize the sum of separable convex functions subjected to resource constraints by observing its local objective function and the information exchanged with its adjacent neighbors. Thus, the problem lies in a distributed framework. In existing literature dealing with similar problems, the measurement of the gradients/subgradients of the objective functions has been applied in the algorithm design. In this paper, by adding stochastic dithers to the local objective functions and constructing randomized differences, we propose a distributed gradient-free algorithm for solving the problem, and show that the algorithm is strongly convergent; that is, the estimates generated from each agent almost certainly converge to the optimal resource allocation solution of the network. Finally, the effectiveness of the algorithm is validated by conducting numerical experiments.

关键词： resource allocation distributed algorithm randomized difference

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Phillips-Heffron model for current-controlled power electronic generation unit

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Journal of Modern Power Systems and Clean Energy 2018年第3期6卷 582-594页

作者： Shulong TAN Hua geng geng YANG Department of Automation Tsinghua University

This paper presents a Phillips-Heffron model for the generation unit with current-controlled(CC) voltage source converter(VSC) as the interface. A concept of current angle is put forward for the CC-VSC, and the relationship between the current angle and the power angle is also quantified. Based on the current angle, a PhillipsHeffron model is established for the generation unit with CC-VSC, considering the dynamic of phase-locked-loop(PLL) in the weak grid. The model demonstrates that small-signal dynamics of the generation unit is similar to that of the traditional synchronous generator(SG) which is characterized by the electromechanical swing *** the dynamics can be depicted by the famous inertia,synchronizing and damping coefficients. Small-signal stability of a CC-VSC-based single machine infinite bus system is analyzed by means of the traditional theory of power system. Based on the relationship between the current angle and the power angle, the Phillips-Heffron model of the CC-VSC is also used in stability analysis of multimachine power system, and parameter optimizations of the CC-VSC are also studied for stability improvement.

关键词： Phillips-Heffron model Voltage source converter Current angle Synchronous generator Small-signal stability

Homogenization of Elliptic Problems with Neumann Boundary Conditions in Non-smooth Domains

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Acta Mathematica Sinica,English Series 2018年第4期34卷 612-628页

作者： Jun geng School of Mathematics and Statistics Lanzhou University

We consider a family of second-order elliptic operators {LE } in divergence form with rapidly oscillating and periodic coefficients in Lipschitz and convex domains in Rn. We are able to show that the uniform WI＇p estimate of second order elliptic systems holds for 2n/n＋1-δ〈p〈2n/n-1＋δ where δ 〉 0 is independent of ~ and the ranges are sharp for n = 2, 3. And for elliptic equations in Lipschitz domains,the W1,p estimate is true for 3/2 -δ 〈 p〈 3 ＋ δ ifn ≥ 4, similar estimate was extended to domains, the WI＇p estimate is true for nconvex domains for 1 〈 p 〈 ∞.

关键词： Homogenization elliptic non-smooth