检索结果-内蒙古大学图书馆

Parallel multi-rate simulation scheme for modular multilevel converter-based high-voltage direct current with accurate simulation of high-frequency characteristics and field programmable gate array-based implementation

引用

High Voltage 2025年第1期10卷 17-31页

作者： Chongru Liu Yanqi Hou Haoyun Dong Yipeng Lv Xinyan Wang Chenbo Su State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

The real-time simulation of the modular multilevel converter-based high-voltage direct current(MMC-HVDC)transmission system has become a popular research ***,in order to meet the real-time performance,the real-time simulation tech-nology will cause additional simulation errors for MMC-HVDC,especially on its fre-quency ***,a parallel multi-rate simulation scheme for MMC-HVDC is developed in this work to ensure accurate simulation of high-frequency ***,a non-error method based on converter transformer decoupling is proposed to decouple the converter and alternating current system;direct current transmission line decoupling and arm decoupling methods are used to achieve decoupling among and within converters.A multi-rate data synchronous mechanism is established by considering the differences among high-frequency characteristics caused by delayed data ***,the computing architectures of the primary system solver and modular multilevel converter controller are designed based on a field programmable gate array(FPGA).The real-time simulation platform for a four-terminal true bipolar MMC-HVDC is constructed based on the FPGA ***,the factors in multi-rate simulation affecting the simulation accuracy of high-frequency characteristics are *** simulator is shown to be accurate in steady and dynamic *** authors also verify its applicability for further research on high-frequency resonance based on control experiments.

关键词： interaction. characteristics scheme

来源：评论

学校读者我要写书评

暂无评论

Photodetector array for measuring the spatial-temporal distribution characteristics of electric field in oil-pressboard insulation based on the Kerr electro-optic effect

引用

High Voltage 2025年第1期10卷 95-105页

作者： Chunjia Gao Bo Qi Chengrong Li Yukung Zheng State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

Accurate measurement and effective analysis of the space electric field and charge characteristics within the oil-pressboard insulation structure of converter transformer are essential for achieving precise insulation structure ***,most electric field measurement methods relying on the Kerr electro-optical effect are limited to single-point *** the complexity of converter transformer insulation struc-tures,including their large scale and the use of various materials,existing technologies and findings struggle to provide comprehensive electric field observations within the oil-pressboard *** leveraging the Kerr electro-optic effect,a high-precision 32-unit photodetector array has been developed to achieve regional measurements of spatial-temporal electric field in oil-pressboard *** array boasts a measure-ment spatial resolution of 1.4 mm^(2)and a sensitivity of 0.15 kV/mm,ensuring mea-surement accuracy exceeding 96.50%.Through practical measurements of the spatial electric field distribution within the oil-pressboard insulation under direct current voltage,the non-uniform distribution of the electric field is effectively captured in ***,the maximum deviation in field strength at different positions within the transformer oil can reach 18.5%.Moreover,as the applied voltage increases,the un-evenness coefficient of the field strength gradually rises,peaking at 1.19,which signifies a progressive expansion in the area affected by electric field *** conducting tests to assess the dispersion of volume resistivity in samples from various positions within large sheets of pressboard,the variation in volume resistivity of materials is posited as one of the contributing factors to the non-uniform distribution of electric field within the *** detailed accomplishments aim to provide essential technical and theoretical support for optimising insulation structure design of converter transformers.

关键词： insulation distribution field

来源：评论

学校读者我要写书评

暂无评论

Modified Dynamic Model and Small-signal Stability Analysis for LCC- HVDC systems

引用

CSEE Journal of power and energy systems 2025年第2期11卷 750-759页

作者： Chunyi Guo Jiaqing Zhang Shuo Yang Huan Li Chuang Fu State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Electric Power Research Institute China Southern Power Grid State Key Laboratory of HVDCGuangzhouChina

Inaccuracy of modeling for line commutated converter based high voltage direct current (LCC-HVDC) systems will degrade the reliability of small-signal stability analysis results. Taking a practical project as the study system, this paper establishes a modified dynamic model by modifying the current switching function, firing angle calculation and DC voltage calculation. Then, the accuracy of the modified model is verified by a detailed electromagnetic transient (EMT) simulation. Finally, with the modified dynamic model, the impact of the control parameters and AC system strength on the small-signal stability of the overall system is investigated by adopting the eigen-analysis. The results clearly demonstrate that the modified model shows higher accuracy than the original model.

关键词： LCC-HVDC modified dynamic model practical project small-signal analysis

来源：评论

学校读者我要写书评

暂无评论

Quantitative analysis on the separated double schottky barrier for ZnO-based ceramic nanowire

引用

Ceramics International 2025年第10期51卷 13537-13544页

作者： Yang, Xiao Zhang, Han Qi, Bo Yu, Zexuan Li, Chuanyang Hu, Jun He, Jinliang State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing102206 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing100084 China

ZnO based ceramic nanowires or whiskers have been reported to possess good nonlinear conducting property similar with ZnO ceramic varistor. The energy band structure and nonlinear conduction process of the ceramic nanowire are different from the traditional back-to-back double schottky barrier structure while a model description has been absent. This paper has taken ceramic nanowire based on ZnO coated with Bi, Co oxide as an instance and proposed a separated double schottky model to quantitatively characterizes the process of interface charges at the reverse and forward bias side which are separately modulated by the corresponding voltage bias and barrier height. Computation result based on the model agree well with the measured nonlinear conducting behavior of a single ZnO ceramic nanowire and its nonlinear mechanism has been analyzed. On this basis, quantitative correlation between the property of a single ZnO ceramic nanowire and the overall nonlinear conducting behavior of its composite has been established. © 2025

关键词： II-VI semiconductors

来源：评论

学校读者我要写书评

暂无评论

Study on Air Gap Breakdown Caused by Metal Dust in DC GIL 11th

Study on Air Gap Breakdown Caused by Metal Dust in DC GIL

引用

11th Frontier Academic Forum of electrical Engineering, FAFEE 2024

作者： Yang, Ruicheng Su, Baoliang Wang, Yuan Geng, Qiuyu Xue, Naifan Li, Qingmin State Key Lab of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing102206 China

ISBN: (纸本)9789819788156

With China's steady progress towards the dual-carbon goal, photovoltaic, hydropower and other large-scale new energy power generation equipment will be integrated into the power system. However, due to China’s vast territory and the geographical distance between the power generation center and the load center, GIL have the advantages of large transportation energy and long transmission distance, and have become the first choice for transmitting electric energy. In recent years, GIL internal insulation faults have occurred frequently, among which are not a few caused by metal dust, and the size of metal dust is small, and the motion law is difficult to observe. In this paper, the diffusion and adsorption movement of metal dust in the air gap are studied. It is found that the unique diffusion phenomenon of metal dust in the air gap is accompanied by a large number of partial discharge phenomena. It is found that the discharge intensity is greatly related to the particle size of metal dust. The larger the particle size of metal dust, the more intense the discharge and the stronger the phenomenon. As the voltage increases, the diffusion and adsorption process of metal dust gradually ends, and the amount of metal dust adsorbed by the upper plate no longer increases, and the air gap breaks down. However, the breakdown voltage decreases by less than 10% compared with the case without metal dust, but there is a big difference in the amplitude of the discharge signal. The principle of affecting the amplitude of the discharge signal is that the lifting of the agglomerated metal dust will cause a large air gap electric field distortion in the air gap, and the size of the agglomerated metal dust affects the amplitude of the discharge signal of the metal dust. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Partial discharges

来源：评论

学校读者我要写书评

暂无评论

Design Considerations on Voltage and Current Transfer Ratio of High-Frequency Transformers

引用

CSEE Journal of power and energy systems 2025年第1期11卷 447-457页

作者： Chen Liu Lei Qi Xiang Cui China Electric Power Planning&Engineering Institute Beijing100120China State Key Laboratory for Alternate Electrical Power System Renewable Energy Sources(North China Electric Power University)Beijing102206China

A high frequency(HF)transformer is key equipment for dc-dc converter to achieve galvanic isolation and voltage *** operating frequency increases,voltage and current transfer ratio of HF transformer may significantly deviate from the turn ratio due to parasitic effects,failing to transfer expected voltage and current from the primary side to the secondary *** this paper,design considerations on voltage and current transfer ratio of the HF transformer are investigated to obtain expected transfer *** revealing parasitic effects on transfer characteristic(TC)of the HF transformer with load,deviation between voltage/current transfer ratio and turn ratio is correlated with the ratio of voltage/current TC resonant frequency and operating ***,constraints for parasitic parameters to obtain expected transfer ratio are proposed,and practical measures to achieve improvements in transformer design are discussed.A 20kHz HF transformer prototype is used as an application,by which evaluations on deviation of voltage/current transfer ratio and turn ratio are verified,and voltage/current transfer performance of the prototype are effectively improved by optimal design based on the proposed principles.

关键词： Capacitance transfer functions transformers

来源：评论

学校读者我要写书评

暂无评论

Introducing deep trap states for high dielectric strength of aramid-based composite films

引用

High Voltage 2025年第1期10卷 197-207页

作者： Wenqi Zhang Qibin Wang Guangyi Shen Sidi Fan Xiaozhou Fan Rui Yang Yunpeng Liu Xiang Yu Fangcheng Lv School of Electrical and Electronic Engineering North China Electric Power UniversityBeijingChina Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

Aramid nanofiber(ANF)-based composites have drawn tremendous interest in high-voltage electrical systems due to their superior insulation strength,thermal stability,and mechanical ***,the filler agglomeration and interface compatibility have retarded further improvement of the dielectric ***,the nano-titanium dioxide(TiO_(2))particles treated by aminopropyl triethoxysilane(APTES)serve as the inorganic fillers,which are doped in the ANF to prepare the composite nano-paper via the blade coating *** electrostatic interaction between the ANF and fillers highly promotes their uniform *** to the pure ANF paper,the composite paper has a denser structure with reduced pores and defects,which significantly improves its dielectric performance with inhibited partial discharge *** a filler loading of 3 wt%(mass fraction),the breakdown strength is increased by 70.5%to a maximum value of 358.1 kV/mm,while the bulk conductivity is minimised to 5.2×10^(-17)S/m,representing an 88.1%*** analysing the energy band structure of each component,energy barriers at the interface for electrons(1.48 eV)and holes(0.40 eV)are *** values indicate deepened trap energy levels,which greatly strengthen the carrier trapping effect for improved dielectric performance.

关键词： composite dielectric strength

来源：评论

学校读者我要写书评

暂无评论

Feasibility Analysis of Terahertz Pulse Application for electrical Equipment Insulation Evaluation 10

Feasibility Analysis of Terahertz Pulse Application for Elec...

引用

10th Symposium on Novel Optoelectronic Detection Technology and Applications

作者： Ren, Hanwen Han, Biao Bian, Guorong Gao, Haoyu Qi, Tianrun Ma, Yiqun Xiao, Tao Gao, Ruize State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing China

ISBN: (数字)9781510688155

ISBN: (纸本)9781510688148

Terahertz pulses have been widely used in many fields such as biomedicine, materials science, imaging technology, etc., but they have not yet given full play to their potential in the field of electrical equipment insulation assessment. In view of the advantages of narrow pulse width and high signal-to-noise ratio of terahertz pulse, this paper proposes a space charge measurement method for insulation based on terahertz pulse, which is aimed at overcoming the limitations of the spatial and temporal resolution of the traditional measurement method, and providing a more powerful means of evaluating the insulation of electrical equipment. This paper mainly focuses on the feasibility of terahertz perturbation of insulation charge. Firstly, the terahertz pulse generation principle of the photoconductive antenna and the factors affecting the electric field strength are analyzed. Further, based on the electro-optical sampling principle, a terahertz pulse generation and time domain waveform detection platform are constructed. Experiments show that the terahertz wave generated by the constructed generation platform has a good pulse waveform. Finally, a terahertz pulse space charge perturbation evaluation platform is constructed. The validation analysis shows that the terahertz pulse has obvious perturbation effect on space charge, and has good feasibility of insulating medium space charge measurement. The related work of this paper can provide a good technical basis and theoretical support for the realization of accurate assessment of the insulation state of electrical equipment. © 2025 SPIE.

关键词： Terahertz waves

来源：评论

学校读者我要写书评

暂无评论

Simulation Calculation of power Frequency Arc Platform in Oil 19th

Simulation Calculation of Power Frequency Arc Platform in Oi...

引用

19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Xue, Xiaoqiang Cheng, Hao Gao, Chunjia Yuan, Haoruo Ge, Hao Qi, Bo State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power University Beijing China

ISBN: (纸本)9789819613823

The significant uncertainty, volatility, and high levels of harmonics resulting from the increased integration of new energy sources impose stricter operational demands on substation equipment. As a critical piece of high-voltage electrical equipment, a transformer fault can compromise the stability of the entire power grid. Among the most severe faults is an internal short-circuit arc fault, which, if not accurately detected and addressed promptly, could lead to explosions or even power outages. Therefore, studying the characteristics of industrial frequency arcs in transformer oil and proposing effective explosion-proof measures for transformers is crucial. Given the high risk and cost associated with arc testing, a simulation approach is employed in this study. The paper analyzes current attenuation waveforms under various parameter combinations using a capacitor-inductor resonance simulation circuit. The optimal capacitor-inductor parameter combination is identified, laying the groundwork for future applications of the capacitor-inductor resonance method in simulating arc tests in oil. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Oil filled transformers

来源：评论

学校读者我要写书评

暂无评论

Distribution Characteristics of Temperature Field Inside Transformer Under Different Ambient Temperatures 19th

Distribution Characteristics of Temperature Field Inside Tra...

引用

19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Cui, Yan Yuan, Haoruo Gao, Chunjia Ge, Hao Cheng, Hao Qi, Bo State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources North China Electric Power University Beijing China

ISBN: (纸本)9789819613823

This study simulates the temperature field distribution inside the transformer under different ambient temperatures. In order to explore the insulation performance of the transformer under extreme ambient temperatures, finite element simulation was used to simulate the distribution of the temperature field inside the transformer at ambient temperatures of −40 ℃, −20 ℃, 0 ℃, 20 ℃ and 40 ℃. The study found that when the ambient temperature is too low, the convection heat dissipation capacity of the transformer oil will be weakened, thereby increasing the temperature inside the core;when the temperature is too high, the temperature field distribution inside the transformer will be more uniform, but the life of the insulating paperboard will be reduced. The temperature rise trend inside the transformer remains consistent under various ambient temperatures, and the hot spot temperature can reach up to 106.4 ℃. The temperature at each moment shows an obvious linear relationship with the ambient temperature. The temperature ranges at various locations inside vary greatly, with the temperature gradually increasing from bottom to top and gradually decreasing from inside to outside. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Distribution transformers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：