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低电容用量高纹波MMC的三次谐波电压注入方法 被引量:6
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作者 孟经伟 周月宾 +1 位作者 张楠 宋强 《电工电能新技术》 CSCD 北大核心 2021年第2期1-8,共8页
针对高纹波模块化多电平换流器(Modular Multilevel Converter,MMC)在感性工况下输出电压能力和功率能力受限问题,对基于三次谐波电压注入的高纹波MMC进行了研究。考虑了MMC电容电压波动的影响,对三次谐波电压注入下MMC电压的输出能力... 针对高纹波模块化多电平换流器(Modular Multilevel Converter,MMC)在感性工况下输出电压能力和功率能力受限问题,对基于三次谐波电压注入的高纹波MMC进行了研究。考虑了MMC电容电压波动的影响,对三次谐波电压注入下MMC电压的输出能力进行了分析,揭示了在不同运行工况下三次谐波注入对MMC最大调制比的提高能力不同。基于感性工况下的调制比可提高程度大于容性工况的特性,提出了高纹波MMC的三次谐波电压注入方法,可弥补感性工况下高纹波运行方式导致的输出电压和无功能力的缺失,将高纹波MMC的输出功率范围扩展到与常规MMC接近,克服了高纹波MMC感性无功输出能力严重受限问题。仿真结果验证了所提方法的有效性。 展开更多
关键词 模块化多电平换流器 电容用量 三次谐波电压注入
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模块化多电平换流器电容用量的标幺化分析与设计方法 被引量:3
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作者 周月宾 宋强 +3 位作者 杨柳 张楠 李政轩 曹琬钰 《电力建设》 CSCD 北大核心 2021年第11期1-12,共12页
子模块电容用量是影响模块化多电平换流器(modular multilevel converter,MMC)体积和成本的关键因素。提出了以单位容量额定储能值作为MMC电容用量的统一的衡量与直接设计指标,建立了直接描述MMC所需额定储能值与电容电压波动率之间关... 子模块电容用量是影响模块化多电平换流器(modular multilevel converter,MMC)体积和成本的关键因素。提出了以单位容量额定储能值作为MMC电容用量的统一的衡量与直接设计指标,建立了直接描述MMC所需额定储能值与电容电压波动率之间关系的标幺化计算模型,使不同额定参数MMC的电容用量的衡量、计算和分析可以得到统一和简化。与以子模块电容值作为分析和设计指标的传统方法相比,MMC额定储能值标幺化计算模型去除了多种参数对计算过程的影响,揭示了基准调制比和输出功率范围是影响MMC额定储能值的关键因素。基于所提出的额定储能值标幺化计算模型,对MMC额定储能设计值随基准调制比和功率输出范围的变化规律进行了详细分析,为MMC电容用量的设计和优化提供了明确的依据。数字仿真和物理试验结果验证了所提方法的正确性。 展开更多
关键词 模块化多电平换流器(MMC) 电容电压波动 电容用量 额定储能值
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Electrochemical hydrogen storage performance of as-cast and as-spun RE-Mg-Ni-Co-Al-based alloys applied to Ni/MH battery 被引量:5
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作者 Yang-huan ZHANG Ya-qin LI +3 位作者 Hong-wei SHANG Zhong-hui HOU Yan QI Dong-liang ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第4期711-721,共11页
The La-Mg-Ni-Co-Al-based AB2-type La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1(x=0,0.05,0.1,0.15,0.2)alloys were prepared via melt spinning.The analyses of the X-ray diffraction(XRD)and scanning electron microscopy(SEM)proved that... The La-Mg-Ni-Co-Al-based AB2-type La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1(x=0,0.05,0.1,0.15,0.2)alloys were prepared via melt spinning.The analyses of the X-ray diffraction(XRD)and scanning electron microscopy(SEM)proved that the experimental alloys contain the main phase LaMgNi4 and the second phase LaNi5.Increasing Y content and spinning rate lead to grain refinement and obvious change of the phase abundance without changing phase composition.Y substitution for La and melt spinning make the life-span of the alloys improved remarkably,which is attributed to the improvement of anti-oxidation,anti-pulverization and anti-corrosion abilities.In addition,the discharge capacity visibly decreases with increasing the Y content,while it firstly increases and then decreases with increasing spinning rate.The electrochemical kinetics increases to the optimum performance and then reduces with increasing spinning rate.Moreover,all the alloys achieve to the highest discharge capacities just at the initial cycle without activation. 展开更多
关键词 Y La substitution spinning rate life-span discharge capacity electrochemical kinetics
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An iterative computation method for interpreting and extending an analytical battery model
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作者 Neng-gan ZHENG Zhao-hui WU +1 位作者 Man LIN Qi-jia WANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第2期279-288,共10页
Battery models are of great importance to develop portable computing systems,for whether the design of low power hardware architecture or the design of battery-aware scheduling policies.In this paper,we present a phys... Battery models are of great importance to develop portable computing systems,for whether the design of low power hardware architecture or the design of battery-aware scheduling policies.In this paper,we present a physically justified iterative computing method to illustrate the discharge,recovery and charge process of Li/Li-ion batteries.The discharge and recovery processes correspond well to an existing accurate analytical battery model:R-V-W's analytical model,and thus interpret this model algorithmically.Our method can also extend R-V-W's model easily to accommodate the charge process.The work will help the system designers to grasp the characteristics of R-V-W's battery model and also,enable to predict the battery behavior in the charge process in a uniform way as the discharge process and the recovery process.Experiments are performed to show the ac-curacy of the extended model by comparing the predicted charge times with those derived from the DUALFOIL simulations.Various profiles with different combinations of battery modes were tested.The experimental results show that the extended battery model preserves high accuracy in predicting the charge behavior. 展开更多
关键词 Analytical battery model lterative computation method Capacity response Charge DISCHARGE
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Operational program for proper capacity of electric bus charging station in Expo 2010
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作者 张维戈 Shi Wei +2 位作者 Sun Bingxiang Jia Rongda Li Xiaoqiang 《High Technology Letters》 EI CAS 2013年第4期437-442,共6页
In the paper,an operational program of electric bus charging station is proposed,which is special for "The Construction Project for Expo 2010 Temporary Electric Bus Charging Station".Based on the quick-chang... In the paper,an operational program of electric bus charging station is proposed,which is special for "The Construction Project for Expo 2010 Temporary Electric Bus Charging Station".Based on the quick-change mode,a vehicle operating schedule model has been established to meet the capacity of transport.Then,according to the quantity of passengers and utilization of batteries,a calculative method of parameters,such as the number of spare batteries and bus departure rules,has been provided.Furthermore,optimal simulation software designed for operating process of the charging station has been identified incorporating actual running data from electric buses and monitoring system of the charging station,and the rationality of the design is verified in the preliminary commissioning and the official operation. 展开更多
关键词 electric bus charging station operational program simulation software
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Research of the Wireless Management System for Solar Street Lamp Based on NanoLOC AVR Module
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作者 张开如 莫伦伟 唐梅玉 《Journal of Measurement Science and Instrumentation》 CAS 2011年第1期55-59,共5页
In order to improve the service life of solar street lamp, it is necessary to manage the lamp's battery in the form of on-line detection via wireless communanication. A wireless managonent systean for solar street la... In order to improve the service life of solar street lamp, it is necessary to manage the lamp's battery in the form of on-line detection via wireless communanication. A wireless managonent systean for solar street lamp based on nanoLOC AVR nttlule is researched in this paper, the system can real-timely detect the solar street lamp's battery voltage, corrent, tonperature, internal resistance, residual capacity and so on. And the collected data is transmitted to computer' s management via wireless connnunication to achieve recording, storage, analysis and processing for various parameters. 展开更多
关键词 solar street lamp nanoLOC AVR module wireless com-munication
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Application of PFMEA for Identification of Self-Recovering Failures in Production Lines for Automatic Assembly of Capacitors
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作者 Todor Neshkov Aleksandar Stefanov Vladislav Ivanov 《Journal of Mechanics Engineering and Automation》 2013年第3期173-178,共6页
Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In mos... Quality control is an important part of the capacitors automatic assembly process. Traditionally this control is being realized through a series of electrical measurements including capacity, tension, and tgct. In most cases, these measurements are not suitable for detecting defects that appear as a result of failures of certain elements of the assembly lines. These so called self-recovering failures very often remain unnoticed, because they do not cause a suspension of the assembly process and if not taken into consideration, they can seriously menace the final product quality. In this paper, the authors use PFMEA to identify and evaluate the risk of the self-recovering failures. They also propose a simple Simulink model, which could be useful when trying to estimate the effect of installing new control devices at an existing assembly line upon its overall reliability and productivity. 展开更多
关键词 FAILURE EFFECT assembly line SIMULATION
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Electron-electron interactions in monolayer graphene quantum capacitors 被引量:1
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作者 Xiaolong Chen Lin Wang Wei Li Yang Wang Zefei Wu Mingwei Zhang Yu Han Yuheng He Ning Wang 《Nano Research》 SCIE EI CAS CSCD 2013年第8期619-626,共8页
We demonstrate the effects of electron-electron (e-e) interactions in monolayer graphene quantum capacitors. Ultrathin yttrium oxide showed excellent per-formance as the dielectric layer in top-gate device geometry.... We demonstrate the effects of electron-electron (e-e) interactions in monolayer graphene quantum capacitors. Ultrathin yttrium oxide showed excellent per-formance as the dielectric layer in top-gate device geometry. The structure and dielectric constant of the yttrium oxide layers have been carefully studied. The inverse compressibility retrieved from the quantum capacitance agreed fairly well with the theoretical predictions for the e--e interactions in monolayer graphene at different temperatures. We found that electron-hole puddles played a significant role in the low-density carrier region in graphene. By considering the temperature-dependent charge fluctuation, we established a model to explain the round-off effect originating from the e-e interactions in monolayer graphene near the Dirac point. 展开更多
关键词 GRAPHENE e-e interaction inverse compressibility quantum capacitance charge fluctuation electron-hole puddles
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NiaSi2O5(OH)4 Multi-Walled Nanotubes with Tunable Magnetic Properties and Their Application as Anode Materials for Lithium Batteries 被引量:13
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作者 Yan Yang Qingqin Liang +4 位作者 dinghong Li Yuan Zhuang Yunhua He Bo Bai Xun Wang 《Nano Research》 SCIE EI CAS CSCD 2011年第9期882-890,共9页
Highly crystalline and thermally stable pure multi-walled Ni3Si2O5(OH)4 nanotubes with a layered structure have been synthesized in water at a relatively low temperature of 200-210 ℃ using a facile and simple metho... Highly crystalline and thermally stable pure multi-walled Ni3Si2O5(OH)4 nanotubes with a layered structure have been synthesized in water at a relatively low temperature of 200-210 ℃ using a facile and simple method. The nickel ions between the layers could be reduced in situ to form size-tunable Ni nanocrystals, which endowed these nanotubes with tunable magnetic properties. Additionally, when used as the anode material in a lithium ion battery, the layered structure of the Ni3Si2O5(OH)4 nanotubes provided favorable transport kinetics for lithium ions and the discharge capacity reached 226.7 mA.h.g-1 after 21 cycles at a rate of 20 mA.g-1, Furthermore, after the nanotubes were calcined (600 ℃, 4 h) or reduced (180℃ 10 h), the corresponding discharge capacities increased to 277.2 mA.h.g-1 and 308.5 mA.h.g-1, respectively. 展开更多
关键词 Silicate nanotubes Ni nanocrystals lithium battery magnetic properties
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