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Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

《能源前沿(英文)》 2014年 第8卷 第3期   页码 386-393 doi: 10.1007/s11708-014-0323-9

摘要: Accurate modeling and parameters of high voltage (HV) grid are critical for stability research of system frequency. In this paper, simulation modeling of the system frequency was conducted of an interconnected power system with HV transmission lines in China. Based on recorded tripping data of the HV transmission lines, system parameters were identified by using genetic algorithm (GA). The favorable agreement between simulation results and recorded data verifies the validity of gird models and the accuracy of system parameters. The results of this paper can provide reference for the stability research of HV power grid.

关键词: high voltage (HV) grid     frequency stability parameter identification     primary frequency regulation (PFR)    

Recent advances toward high voltage, EC-free electrolytes for graphite-based Li-ion battery

Tong Zhang, Elie Paillard

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 577-591 doi: 10.1007/s11705-018-1758-z

摘要:

Lithium-ion batteries are a key technology in today’s world and improving their performances requires, in many cases, the use of cathodes operating above the anodic stability of state-of-the-art electrolytes based on ethylene carbonate (EC) mixtures. EC, however, is a crucial component of electrolytes, due to its excellent ability to allow graphite anode operation–also required for high energy density batteries–by stabilizing the electrode/electrolyte interface. In the last years, many alternative electrolytes, aiming at allowing high voltage battery operation, have been proposed. However, often, graphite electrode operation is not well demonstrated in these electrolytes. Thus, we review here the high voltage, EC-free alternative electrolytes, focusing on those allowing the steady operation of graphite anodes. This review covers electrolyte compositions, with the widespread use of additives, the change in main lithium salt, the effect of anion (or Li salt) concentration, but also reports on graphite protection strategies, by coatings or artificial solid electrolyte interphase (SEI) or by use of water-soluble binder for electrode processing as these can also enable the use of graphite in electrolytes with suboptimal intrinsic SEI formation ability.

关键词: lithium-ion     electrolyte     solid electrolyte interphase     additives     high voltage     graphite    

Experimental study of pollution effect on the behavior of high voltage insulators under alternative current

Hani BENGUESMIA, Nassima M’ZIOU, Ahmed BOUBAKEUR

《能源前沿(英文)》 2021年 第15卷 第1期   页码 213-221 doi: 10.1007/s11708-017-0479-1

摘要: In this paper, the impact of the conductivity and the distribution of pollution on the behavior of the high voltage insulator cap and pin 1512L, artificially polluted is described. An experimental model in form of a disc is proposed. This experimental model reproduces the real model which is the 1512L insulator. Besides, a comparative study is presented. For this comparative study, different solutions are adopted to s`imulate the pollution (containing NaCl+ distilled water) that has different conductivities for a discontinuous distribution of the pollution on the insulator under an AC voltage. Furthermore, the influence of the pollution on the flashover voltage and the leakage current is studied. Finally, the behavior of real and experimental model of the insulator is investigated.

关键词: 1512L insulator     circular model     artificial pollution     flashover     leakage current     discontinuous pollution     high voltage    

Development and advances in modular multilevel converter based HVDC projects in China

《工程管理前沿(英文)》 2023年 第10卷 第1期   页码 183-189 doi: 10.1007/s42524-022-0248-7

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关键词: high voltage direct current     power converter     power systems     renewable energy     ultra-high voltage    

大中功率节能调速传动的合理电压等级

马小亮

《中国工程科学》 2001年 第3卷 第11期   页码 80-84

摘要:

大中功率风机和泵采用变频调速可节约大量电能,大部分功率在0.2~2 MW范围中。我国现在200 kW以上的电机多是中压,现行中压电网多为10 kV,选用10 kV直接变频从技术和经济角度看都不太合理。由于变频器输入侧都有变压器,因此电机和变频器没有必要和电网一致。文章讨论不同功率段的合理电压等级以及在电机电压和电网电压不同情况下当变频器出现故障时如何实现旁路工作。

关键词: 大中功率     节能调速     合理电压等级     低压变频     中压变频     旁路    

High purity Mn

Xiaoqiang SHAN, Fenghua GUO, Wenqian XU, Xiaowei TENG

《能源前沿(英文)》 2017年 第11卷 第3期   页码 383-400 doi: 10.1007/s11708-017-0485-3

摘要: Developing electrodes with high specific energy by using inexpensive manganese oxides is of great importance for aqueous electrochemical energy storage (EES) using non-Li charge carriers such as Na-or K-ions. However, the energy density of aqueous EES devices is generally limited by their narrow thermodynamic potential window (~1.23 V). In this paper, the synthesis of high purity layered Mn O nanoparticles through solid state thermal treatment of Mn O spinel nanoparticles, resulting in a chemical formula of [Mn ][Mn O ], evidenced by Rietveld refinement of synchrotron-based X-ray diffraction, has been reported. The electro-kinetic analyses obtained from cyclic voltammetry measurements in half-cells have demonstrated that Mn O electrode has a large overpotential (~ 0.6 V) towards gas evolution reactions, resulting in a stable potential window of 2.5 V in an aqueous electrolyte in half-cell measurements. Symmetric full-cells fabricated using Mn O electrodes can be operated within a stable 3.0 V potential window for 5000 galvanostatic cycles, exhibiting a stable electrode capacity of about 103 mAh/g at a C-rate of 95 with nearly 100% coulombic efficiency and 96% energy efficiency.

关键词: manganese oxides Mn5O8     high voltage     aqueous Na-ion storage    

一种低电流纹波的低压大电流DC-DC变换器的研究

王萍,孙栩,宋良瑜

《中国工程科学》 2005年 第7卷 第4期   页码 59-63

摘要:

通过n个倍流整流结构交错并联方式用以进一步减小纹波电流。给出了电路的开关信号波形和仿真模型,并使用Pspice仿真软件对该模型进行仿真,取得满意效果。最后通过实验验证。这种结构特别适用于通信设备、计算机、宇航等领域的电源。

关键词: 低压大电流DC-DC变换器     倍流整流     交错并联    

A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1208-1220 doi: 10.1007/s11705-023-2304-1

摘要: The combination of high-voltage windows and bending stability remains a challenge for supercapacitors. Here, we present an “advantage-complementary strategy” using sodium lignosulfonate as a pseudocapacitive molecule to regulate the spatial stacking pattern of graphene oxide and the interfacial architectures of graphene oxide and polyaniline. Flexible and sustainable sodium lignosulfonate-based electrodes are successfully developed, showing perfect bending stability and high electronic conductivity and specific capacitance (521 F·g−1 at 0.5 A·g–1). Due to the resulting rational interfacial structure and stable ion-electron transport, the asymmetric supercapacitors provide a wide voltage window reaching 1.7 V, outstanding bending stability and high energy-power density of 83.87 Wh·kg–1 at 3.4 kW·kg–1. These properties are superior to other reported cases of asymmetric energy enrichment. The synergistic strategy of sodium lignosulfonate on graphene oxide and polyaniline is undoubtedly beneficial to advance the process for the construction of green flexible supercapacitors with remarkably wide voltage windows and excellent bending stability.

关键词: molecular synergy     pseudocapacitive lignosulfonate     flexible electronic devices     asymmetric supercapacitor     wide voltage windows    

高电压快充钴酸锂正极——关键挑战、改性策略与未来展望 Review

王功瑞, 毕志宏, 张安萍, Pratteek Das, 林虎, 吴忠帅

《工程(英文)》 2024年 第37卷 第6期   页码 97-120 doi: 10.1016/j.eng.2023.08.021

摘要:

为了促进高端便携式电子产品进一步发展,迫切需要发展具有高能量密度和高功率密度特性(简称“双高”)的锂离子电池(LIBs)。钴酸锂(LiCoO2)是目前商业化最为成功的正极材料,却仍然面临着工作电压较低和快充能力不足的挑战,远未达到双高储能目标的要求。在此,我们系统地总结和讨论了高电压和快充钴酸锂正极的研究现状,深入探讨了该领域的关键基础挑战、多种改性策略的最新研究进展和未来展望。本文首先全面详细地讨论了钴酸锂关键失效机制,包括体相结构退化、界面结构失稳、非均质反应过程和缓慢的界面反应动力学。随后,我们对已发展的改性策略和改性机制进行了归纳总结,分为通过元素掺杂(包括锂位点、钴位点、氧位点和多位点掺杂)提升锂离子扩散速率和体相结构稳定性,通过表面包覆(包括电介质、离子导体、电子导体材料及其组合)提升表界面结构稳定性和离子/电子导电性,纳米化,多策略组合,及其他策略(包括电解质、粘合剂、电极的曲折度、充电协议和预锂化方法的优化)。最后,我们对前瞻性观点和具有前景的研究方向进行了深入阐述,为设计和实现用于下一代双高锂离子电池的高电压快充钴酸锂正极提供了独到的建议和理论指导。

关键词: 钴酸锂     高能量/功率密度     快充     高电压     锂离子电池    

一种具有高电压传输比的新型Cuk矩阵变换器

张小平,朱建林,唐华平,张炳根,柳莎莎

《中国工程科学》 2008年 第10卷 第4期   页码 78-83

摘要:

对传统矩阵变换器存在电压传输比低的缺陷进行研究,提出一种新型的称为Cuk矩阵变换器的电路拓扑结构。介绍了该拓扑结构的基本构成及其工作原理,推导了其电压传输比与占空比之间函数关系的解析表达式,阐述了所采用的双闭环控制策略的基本设计方法,并通过仿真对其有效性和可行性进行了验证。结果表明:该拓扑结构能实现输出电压和频率的任意调节,其电压传输比可大于1,也可小于1,且直接输出标准的正弦波而无需滤波环节,有效地解决了传统矩阵变换器电压传输比低的难题,具有一定的应用价值。

关键词: Cuk矩阵变换器     电路拓扑     电压传输比     双闭环控制     仿真    

Solid-state transformer-based new traction drive system and control

Jianghua FENG, Jing SHANG, Zhixue ZHANG, Huadong LIU, Zihao HUANG

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 411-426 doi: 10.1007/s11465-018-0467-0

摘要:

A new type of traction drive system consisting of solid-state traction transformer (SSTT), inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining high-voltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The carrier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.

关键词: solid-state traction transformer     high-voltage cascaded rectifier     LLC resonant converter     synchronous rotating reference frame     carrier-interleaving phase shift control     secondary pulsating voltage     beat frequency    

Data-driven consumer-phase identification in low-voltage distribution networks considering prosumers

《能源前沿(英文)》 doi: 10.1007/s11708-024-0946-4

摘要: Knowing the correct phase connectivity information plays a significant role in maintaining high-quality power and reliable electricity supply to end-consumers. However, managing the consumer-phase connectivity of a low-voltage distribution network is often costly, prone to human errors, and time-intensive, as it involves either installing expensive high-precision devices or employing field-based methods. Besides, the ever-increasing electricity demand and the proliferation of behind-the-meter resources have also increased the complexity of leveraging the phase connectivity problem. To overcome the above challenges, this paper develops a data-driven model to identify the phase connectivity of end-consumers using advanced metering infrastructure voltage and current measurements. Initially, a preprocessing method that employs linear interpolation and singular value decomposition is adopted to improve the quality of the smart meter data. Then, using Kirchoff’s current law and correlation analysis, a discrete convolution optimization model is built to uniquely identify the phase to which each end-consumer is connected. The data sets utilized are obtained by performing power flow simulations on a modified IEEE-906 test system using OpenDSS software. The robustness of the model is tested against data set size, missing smart meter data, measurement errors, and the influence of prosumers. The results show that the method proposed correctly identifies the phase connections of end-consumers with an accuracy of about 98%.

关键词: consumer-phase identification     data-driven     low-voltage distribution network     advanced metering infrastructure     singular value decomposition    

电缆测温系统在工厂供配电系统中的应用

阎红

《中国工程科学》 2007年 第9卷 第11期   页码 172-174

摘要:

探讨了在工矿企业中10kV高压电力电缆在线运行温度检测的必要性与实际应用;列举了感温元件 的选型方法以及温度监测系统的组成与运行;介绍了信息处理软件和故障诊断专家系统软件、电力设备底层 信息网、现场总线技术在电力系统中的应用;实现了不停电状态下对高压电缆及电缆接头等各种电缆的故障 在线监测及诊断功能。

关键词: 10kV高压电力电缆     终端头     温度传感器     监测系统    

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

《能源前沿(英文)》 2022年 第16卷 第6期   页码 943-955 doi: 10.1007/s11708-021-0793-5

摘要: This paper investigates and discusses the interaction stability issues of a wind farm with weak grid connections, where the wind turbines (WTs) are controlled by a new type of converter control strategy referred to as the voltage source (VS) control. The primary intention of the VS control method is to achieve the high-quality inertial response capability of a single WT. However, when it is applied to multiple WTs within a wind farm, its weak-grid performance regarding the stability remains concealed and needs to be clarified. To this end, a frequency domain model of the wind farm under the VS control is first developed. Based on this model and the application of a stability margin quantification index, not only the interactions between the wind farm and the weak grid but also those among WTs will be systematically assessed in this paper. A crucial finding is that the inertial response of VS control has negative impacts on the stability margin of the system, and the dominant instability mode is more related to the interactions among the WTs rather than the typical grid-wind farm interaction. Based on this knowledge, a stabilization control strategy is then proposed, aiming for stability improvements of VS control while fulfilling the demand of inertial responses. Finally, all the results are verified by time-domain simulations in power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC).

关键词: weak grids     voltage source (VS) control     wind turbine (WT)     stabilization control     wind farm     inertial response    

标题 作者 时间 类型 操作

Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

期刊论文

Recent advances toward high voltage, EC-free electrolytes for graphite-based Li-ion battery

Tong Zhang, Elie Paillard

期刊论文

Experimental study of pollution effect on the behavior of high voltage insulators under alternative current

Hani BENGUESMIA, Nassima M’ZIOU, Ahmed BOUBAKEUR

期刊论文

Development and advances in modular multilevel converter based HVDC projects in China

期刊论文

大中功率节能调速传动的合理电压等级

马小亮

期刊论文

High purity Mn

Xiaoqiang SHAN, Fenghua GUO, Wenqian XU, Xiaowei TENG

期刊论文

一种低电流纹波的低压大电流DC-DC变换器的研究

王萍,孙栩,宋良瑜

期刊论文

A pseudocapacitive molecule-induced strategy to construct flexible high-performance asymmetric supercapacitors

期刊论文

高电压快充钴酸锂正极——关键挑战、改性策略与未来展望

王功瑞, 毕志宏, 张安萍, Pratteek Das, 林虎, 吴忠帅

期刊论文

一种具有高电压传输比的新型Cuk矩阵变换器

张小平,朱建林,唐华平,张炳根,柳莎莎

期刊论文

Solid-state transformer-based new traction drive system and control

Jianghua FENG, Jing SHANG, Zhixue ZHANG, Huadong LIU, Zihao HUANG

期刊论文

Data-driven consumer-phase identification in low-voltage distribution networks considering prosumers

期刊论文

电缆测温系统在工厂供配电系统中的应用

阎红

期刊论文

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

期刊论文

特高压输电工程(英文)

2022年12月10日

会议视频