检索结果-内蒙古大学图书馆

SSRN 2022年

作者： Liu, Shuming Liu, Shuqi Wang, Qian Zuo, Zhou Liang, Xidong Chen, Zhong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China School of Material Science and Engineering Nanyang Technological University 639798 Singapore

Insulator is an important component of outdoor insulation systems. It works in complex environments and faces a series of problems such as surface contamination, loss of hydrophobicity, accumulation of surface charges, which may eventually lead to flashover. Aiming to solve these problems in a simple and scalable method, we propose a multifunctional nano-coating based on SiO 2 /PDMS/EP. By the combination of multiscale structure and low surface energy modification, this coating shows excellent water-repellency performance, a large contact angle greater than 160° and a small rolling angle near 0° are achieved on coated silicone rubber, which enables the surface with excellent self-cleaning performance. Benefiting from the multiscale roughness, the heat transfer is inhibited by the reduced contact area, which further slows down the icing process on coated silicone rubber. The de-icing force on coated silicone rubber is also smaller than that on pristine silicone rubber. This coating also introduces many shallow traps to the surface, which is beneficial to the fast surface charge dissipation in a short time. Besides, the high water-repelling ability can promote the droplet to roll away under the action of electrical field force, which alleviates the electrical distortion caused by the droplets. As a result, the wet flashover voltage of coated silicone rubber is 60% higher than that of pristine silicone rubber. This multifunctional coating is a facile, scalable, and effective approach to improving the comprehensive surface performance of insulators. © 2022, The Authors. All rights reserved.

关键词： Flashover

来源：评论

学校读者我要写书评

暂无评论

Short-term power Prediction Based on Improved NWP Data Considering Wind Speed Distribution Inner Wind Farm

Short-term Power Prediction Based on Improved NWP Data Consi...

引用

IEEE Conference on Energy Internet and Energy system Integration (EI2)

作者： Wei Ma Ying Qiao ZongXiang Lu ZhiFeng Liang JiaMing Li YuChen Hao State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments of Electrical Engineering Tsinghua University Beijing China State Grid Corporation of China Beijing China State Grid Jiangsu Power Grid Corporation Nanjing China

The wind farm has only one NWP data point, which cannot accurately reflect the wind resources inside the wind farm. To solve the problem of a poor match between short-term wind power prediction numerical weather forecast and wind farm measured weather. Put forward a kind of based on clustering and temporal characteristics of the modified liters of scale wind power prediction method, first of all, using EOF orthogonal decomposition method to extract the features of each fan, using hierarchical analysis method of the characteristics of the data matrix clustering, and then, each cluster sample selected representative of a fan, using the error transfer characteristic of the NWP data sequence is modified. Finally, The CNN prediction model is used for power prediction, and the weight is determined according to the cluster sample size. A wind farm in northern Hebei, China, is used to verify the effectiveness of the proposed method.

关键词： Fans Wind speed system integration Wind farms Wind power generation Predictive models Feature extraction

来源：评论

学校读者我要写书评

暂无评论

In-situ Monitoring of Maximum and Average Chip Junction Temperature within Multichip IGBT power Modules Using Kelvin Emitter Voltage

引用

IEEE Journal of Emerging and Selected Topics in power Electronics 2025年

作者： Yang, Jianxiong Ran, Li Che, Yanbo Du, Mingxing Tianjin University of Technology Tianjin Key Laboratory of Control Theory and Applications in Complicated System Tianjin300384 China Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology School of Electrical Engineering Chongqing400044 China University of Warwick School of Engineering CoventryCV4 7AL United Kingdom Tianjin University Key Laboratory of Smart Grid of Ministry of Education School of Electrical and Information Engineering Tianjin300072 China

Parallel configurations of power chips within a multichip IGBT power module (M-IGBT-PM) are employed to meet the required current and power ratings. When the internal chips of an M-IGBT-PM experience uneven temperature distributions and package aging, it becomes challenging to determine the maximum and average temperatures of the chips within the module. This paper investigates the relationship between four transient thermal-sensitive electrical parameters (T-TSEPs) derived from the Kelvin emitter voltage and the chip junction temperature, while establishing relevant mathematical models. It compares the sensitivity and linearity of these four T-TSEPs, and also assesses the influence of external gate resistance, bus voltage, and load current on each of them. A key innovation in this paper is the proposal of a method for monitoring the maximum and average temperatures across the chips within the M-IGBT-PM, which is not influenced by the load current. The experimental results suggest that the temperature derived from the quasi-turn-on delay time is a good approximation of the maximum chip temperature, whereas the temperatures predicted by the other T-TSEPs are nearer to the average temperature. © 2025 IEEE.

关键词： Insulated gate bipolar transistors (IGBT)

来源：评论

学校读者我要写书评

暂无评论

Numerical and Experimental Research on Electromagnetic-Thermal and Leakage Defects Characteristics of the High Voltage Cable Terminal

SSRN

引用

SSRN 2023年

作者： Liu, Xingmou Gu, Yan Li, Lei Yang, Yongming Cheng, Peng Jadoon, Ammad Chongqing Key Laboratory of Complex Systems and Bionic Control Chongqing University of Posts and Telecommunications Chongqing400065 China State Key Laboratory of Power Transmission Equipment & System Security and New Technology School of Electrical Engineering Chongqing University Chongqing400044 China State Grid Sichuan Electric Power Company Chengdu Power Supply Company Chengdu610000 China NFC-Institute of Engineering &Technology Multan Pakistan

Thermal and insulation performance of the High Voltage Cable Terminal (HVCT) could effectively improve the reliability and economy of power energy transmission. In this paper, a numerical model of the electromagnetic heat flow field was proposed to analyze the heat transfer and temperature characteristics of HVCT under oil leakage defects. This model was the first validated using operation data from the actual equipment and the relative error was less than 1.51%. The effects of oil leakage fault on the global and local temperature distribution of the HVCT were then investigated under different load currents. In addition, the local temperature rise effect of different ambient temperatures on the HVCT oil leakage defect was also considered. Finally, combined with reference indicators such as oil level, temperature, and temperature gradient, a qualitative and quantitative evaluation of the oil leakage fault of HVCT was performed. The results showed that the temperature of the core, surface, and their maximum temperature gradient were linearly related to the ambient temperature. However, the temperature of the core at the oil leak exceeded the normal temperature by up to 7.2 °C with 1000A load current, and the temperature gradient change reaches 681.3 °C/m, which indicated that the convection heat dissipation effect of the oil-deficient part was poor, and the heat accumulates near the cable core. Therefore, the numerical model and analytical results presented in this paper provided an important method for online temperature monitoring and fault analysis of HVCTs. © 2023, The Authors. All rights reserved.

关键词： Thermal gradients

来源：评论

学校读者我要写书评

暂无评论

A Comparative Study of the Virtual Synchronous Compensator on the Voltage Stability Enhancement

A Comparative Study of the Virtual Synchronous Compensator o...

引用

Renewable Energies and Smart Technologies (REST), International Conference on

作者： Zhi Xu Yongping Chen Baoyu Zhai Guanchu Chen Qi Yang Junru Chen Electric Power Research Institute of State Grid Xinjiang Electric Power Co. LTD Urumqi Xinjiang China Xinjiang Key Laboratory of Whole Process Simulation for Power System Urumqi Xinjiang China Xinjiang University Urumqi Xinjiang China

ISBN: (纸本)9781665409728

In a higher power electronics and higher renewable penetration power system, insufficient reactive power provision from the renewable generation will lead to the voltage instability. In order to confront this issue, the reactive power compensation devices, such as capacitor bank, static var compensator and static var generator has been widely used coherent to the loading and renewable generation. However, in such the modern power system, the number of the voltage sources has been reduced. A pure reactive power injection cannot fully meet the voltage stability requirement. The virtual synchronous compensator, based on the grid-forming converter, has been proposed recently to provide a fixed voltage setup or establish a high electrical potential in the system. However, whether this new device can help improve the voltage stability and presents a better performance than the well-known reactive power compensator is not known. This paper contributes to compare the performance of the virtual synchronous compensator with other devices in various scenarios. The simulation results in Matlab/Simulink serves to verify the effectivity of the virtual synchronous compensator on the voltage stability enhancement.

关键词： Performance evaluation Reactive power Renewable energy sources simulation Capacitors Static VAr compensators Voltage

来源：评论

学校读者我要写书评

暂无评论

A fast boundary protection for an AC transmission line connected to an LCCHVDC inverter station

引用

Protection and control of Modern power systems 2020年第1期5卷 328-339页

作者： Zhen Liu Houlei Gao Sibei Luo Le Zhao Yuyao Feng Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityNo.17923Jingshi RoadJinan 250061China Electric Power Research Institute of State Grid Shanghai Electric Power Company No.171Handan RoadShanghaiChina

For AC transmission lines connected to an LCC-HVDC inverter station,commutation failure can lead to the wrong operation of traditional *** solve the problem,this paper proposes a fast protection scheme using transient information from one end of the AC *** boundary frequency characteristics of the AC line connected to LCC-HVDC inverter are analyzed *** reveals the existence of significant attenuation on both high frequency signals and some specific frequency *** on the boundary characteristics,a novel boundary protection principle utilizing a backward traveling wave is then proposed.A PSCAD/EMTDC simulation model of a±800 kV LCC-HVDC and 500 kV AC transmission system is established,and different fault cases are *** simulation results prove that the novel protection principle is immune to commutation failure,fault resistance and fault type.

关键词： LCC-HVDC Commutation failure Transient protection AC transmission line Inverter station Boundary characteristics

来源：评论

学校读者我要写书评

暂无评论

Impedance Modeling and Stability Analysis of a Three-phase Three-level NPC Inverter Connected to the Grid

引用

CSEE Journal of power and Energy systems 2020年第2期6卷 270-278页

作者： Bo Zhang Xiong Du Jingbo Zhao Jiapei Zhou Xiaoming Zou State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University) Shapingba DistrictChongqing 400044China Power System Technology Center Electric Power Research Institute of State GridJiangsu Electric Power Co.Ltd.Jiangsu 320115China HVDC Simulation Center Department of HVDC technologyGlobal Energy Interconnection Research InstituteBeijing 102209China

The interaction between grid-connected inverters and the grid may cause stability issues,and compromise the reliable operation of the *** study investigates the stability of a three-level neutral point clamped(NPC)inverter connected to the grid using impedance-based *** the impedance model of a three-phase three-level NPC inverter has not yet been reported,this study fills the literature gap by analyzing the influence of three-level DC-side neutral point control on the impedance *** fully considering the DC bus dynamics and DC voltage control loop,and the current loop and phase-locked loop(PLL),the admittance model of a three-phase three-level NPC inverter is established and verified by ***,in the stability analysis of a threelevel NPC inverter grid-connected system,the frequency coupling introduced by the PLL and DC bus dynamics is included with the help of an established admittance *** stability of the grid-connected system under different grid short circuit ratios(SCR)and operating power levels is analyzed according to the Nyquist stability *** experimental results revealed that the established impedance model of the three-phase three-level NPC inverter can properly represent the stability of this system.

关键词： Grid-connected inverter neutral point control stability three-level

来源：评论

学校读者我要写书评

暂无评论

Planning of active power distribution network based on source-network-load collaborative optimization 16

Planning of active power distribution network based on sourc...

引用

16th IET International Conference on AC and DC power Transmission, ACDC 2020

作者： Jiang, Zhicheng Yu, Qingguang Li, Ang Xiong, Yufeng Long, Gaoxiang Liu, Yuming Key Laboratory of Modern Power System Simulation and Control and Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China State Key Laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (纸本)9781839533914

With the fast development of renewable energy generation, the randomness and volatility seriously threaten the stability of the power system. In order to improve the consumption rate of renewable energy and the economic benefit, the source-network-load collaborative optimization is put forward and widely used in the power system. And the active power distribution network which consists of the energy storage devices and flexible load is the best carrier to realize it. Based on the active power distribution network planning, this paper firstly designs an economic index covering construction cost and operation cost as the optimization objective. Then with the physical constraints consisting of the physical features of generation units, energy storage devices and flexible load, the source-network-load collaborative optimization model of active power distribution network is established. Finally, a case of city distribution network is presented to verify the effect of source-network-load collaborative optimization and the efficiency of the optimization model. © 2020 Institution of Engineering and Technology. All rights reserved.

关键词： Optimization

来源：评论

学校读者我要写书评

暂无评论

Space Charge Transport of $\boldsymbol{\text{Al}_2 \mathrm{O}_3}$ /Silicone Rubber Composites Under Thermal Aging

Space Charge Transport of $\boldsymbol{\text{Al}_2 \mathrm{O...

引用

International Conference on High Voltage Engineering and Application, ICHVE

作者： Yunxiao Zhang Chenning Yan Kai Wu Yuanxiang Zhou Tianfeng Zhang College of Electrical Engineering and Automation Fuzhou University Fuzhou Fujian China Department of Electrical Engineering State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Tsinghua University Beijing China The Wind Solar Storage Division of State Key Laboratory of Power System and Generation Equipment School of Electrical Engineering Xinjiang University Urumqi China Electric Power Research Institute Anhui Electric Power Company of State Grid Hefei China

ISBN: (数字)9781665407502

ISBN: (纸本)9781665407519

Silicone rubber (SIR) has been widely used in the insulation of cable accessories due to its excellent performance. In this paper, pure SIR and nano $\boldsymbol{\text{Al}_2 \mathrm{O}_3 / \text{SIR}}$ composites are thermally aged for 0–80 days at $\boldsymbol{200^{\circ} \mathrm{C}}$ . The effects of long-term thermal aging on the space charge transport are analyzed. The results show that with the increase of thermal aging time, the accumulation of heteropolar charge of pure SIR and nano $\boldsymbol{\text{Al}_{2}\mathrm{O}_{3}/\text{SIR}}$ composites gradually decreases and changes to the accumulation of homopolar charge. Compared with pure SIR, the space charge accumulation of $\boldsymbol{\text{Al}_{2}\mathrm{O}_{3}/\text{SIR}}$ composites decreases significantly and changes little with the increase of thermal aging time. It is believed that when doped nano $\boldsymbol{\text{Al}_{2}\mathrm{O}_{3}}$ in SIR, the increase of carrier mobility and the introduction of metal oxides reacting with fallen free radicals to form stable compounds both lead to less space charge accumulation of $\boldsymbol{\text{Al}_{2}\mathrm{O}_{3}/\text{SIR}}$ composites.

关键词： Nanocomposites Impurities Metals High-voltage techniques Aging Space charge Thermal analysis

来源：评论

学校读者我要写书评

暂无评论

Dc-Side Synchronous Active power control of Two-Stage Photovoltaic Generation for Frequency Support in Islanded Microgrids

SSRN

引用

SSRN 2022年

作者： Zhong, Cheng Zhou, Yang Chen, Jikai Liu, Zhanjie Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin 132012 China State Grid Shandong Weihai Electric Power Co. Ltd Weihai China State Grid Energy Research Institute Co. Ltd Beijing102209 China

Virtual synchronous generator control (VSG) is an attractive method for the grid-tied inverter to provide inertia and frequency support. However, it brings some troubles on DC-link voltage control when it is applied to two-stage photovoltaic (PV) power generation. This study proposes a DC-Side synchronous active power control for two-stage photovoltaic (PV) power generation without energy storage. Synchronous active power control l is applied to DC-DC converters, while the grid-tied inverter still maintains the DC-link voltage constant. The DC-DC converters flexibly regulate active power to provide the simultaneous inertial and primary frequency response like a synchronous generator. A simple sensorless iterative maximum power estimation method is introduced and integrated into the DC-side VSG strategy. The maximum available power under variable irradiance conditions can be obtained. The effectiveness and advantages of the control strategy are validated through case studies on an island microgrid that included PV generations with a DC-bus collection system. © 2022, The Authors. All rights reserved.

关键词： power control

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：