检索结果-内蒙古大学图书馆

China International Electrical and energy Conference (CIEEC)

作者： Zhenyang Wang Gangui Yan Yue Zhao Jili Peng Dazhong Wang Shuang Ren Dept. Ministry of Education Key Laboratory of Modern Power System Simulation control and Green Power Technology Northeast Electric Power University Jilin China Dept. State Grid Hengyang Power Supply Branch State Grid Hunan Power Supply Hunan China

Aiming at the problem of low-frequency oscillation when photovoltaic power generation is connected to weak AC system, a linearization model of photovoltaic power generation is established, which ignores current inner loop and considers inertia control. The influence of various leading factors on low-frequency oscillation modes of photovoltaic power generation is analyzed. Finally, a low-frequency oscillation stabilizer (SSDC) is designed according to the phase compensation method to suppress the low-frequency oscillation of power system. The results show that the increase of input power of DC capacitor and the decrease of proportional control parameters of DC voltage loop and PLL will lead to the decrease of system damping and stability. Finally, the electromagnetic simulation model of weak AC system with photovoltaic power generation is built on PSCAD/EMTDC platform, which verifies the validity of eigenvalue analysis results and SSDC.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Fault Detection Method for Insulators Using Improved YOLOv4

Journal of Network Intelligence

引用

Journal of Network Intelligence 2022年第4期7卷 818-834页

作者： Zhao, Li-Quan Jiang, Zi-Cong Teng, Zi-Ming Jia, Yan-Fei Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University 168 Changchun Road Jilin132012 China Graduate school of Information Science and Electrical Engineering Kyushu University Fukuoka819-0395 Japan College of information and communication Jilin University Changchun130012 China School of Electrical and Information Engineering Beihua University Jilin132013 China

A defective insulator detection method based on improved You Only Look Once version 4 (YOLOv4) is proposed to improve the precision of defective insulator detection. This method designs a dual-branch attention block by simulating the attention process of the human eye, and introduces it into the backbone of YOLOv4 to extract richer information on defective insulator features. To make the output feature map of shallow layer network fuse more different scale features, a path aggregation network has been designed. To improve detection accuracy, the spatial pyramid pooling has been replaced by atrous spatial pyramid pooling. A dynamic non-maximum suppression method is proposed to improve defective insulator detection accuracy. It employs an adaptive threshold control strategy and weighted operation to full use of the predicted box. We compare our method with defective insulator detection methods based on YOLO and R-CNN. Our simulation results show that the proposed method is more accurate than defective insulator detection methods based on YOLO, and has a faster detection speed than methods based on R-CNN. Compared with the defective insulator detection method based on R-CNN that has the highest mean average precision, the mean average precision of the proposed method is lower, but its detection speed is faster. Compared with YOLOv4, its detection speed is slower, but the mean average precision is higher. The proposed method strikes a satisfactory tradeoff between detection speed and mean average precision. © 2022, Taiwan Ubiquitous Information CO LTD. All rights reserved.

关键词： Object detection

来源：评论

学校读者我要写书评

暂无评论

Selective Preferred Orientation for High-Performance Antimony Selenide Thin-Film Solar Cells Via Substrate Surface Modulation

SSRN

引用

SSRN 2022年

作者： Zhou, Jing Zhu, Jiawei He, Weilan Cao, Yu Pang, Jinbo Ni, Jian Zhang, Jianjun School of Chemical Engineering Northeast Electric Power University Jilin132012 China Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education School of Electrical Engineering Northeast Electric Power University Jilin132012 China University of Jinan Jinan250022 China College of Electronic Information and Optical Engineering Nankai University Tianjin300350 China

Antimony selenide (Sb2Se3) has rapidly emerged in the field of photovoltaics using one-dimensional crystal structure. However, the power conversion efficiency (PCE) of Sb2Se3 solar cells is influenced by the orientation of the Sb2Se3 photoactive layers. In this study, we investigate the influence of substrate properties on the preferred orientation and microstructure of Sb2Se3 films systematically. With the rise of substrate surface temperature and the decline of substrate surface bonding energy, the preferred orientation of the Sb2Se3 films altered from (hk0) to (hk1) and finally to (002). After summarizing the performance of different preferentially oriented Sb2Se3 solar cells, the results showed that the (hk0)-preferentially oriented devices exhibited a poor performance of less than 1.1%. As the preferred orientation of Sb2Se3 absorbers changed from (hk0) to (hk1), the carrier transport changed from inter-ribbon charge hopping to transportation along the (Sb4Se6)n ribbons. This enhanced the carrier transport efficiency, thereby leading to the enhancement of the PCE to 2%–3%. Furthermore, when the (002) texture coefficient (TC) of the Sb2Se3 films was between 1.8 and 3.6, the PCE of the devices was further enhanced to above 3.5%. A maximum PCE of 4.79% can be obtained when the (002) TC was 3.24. This study reveals the relationship between the Sb2Se3 film preferred orientation and device performance, and demonstrates an effective way to precisely control the Sb2Se3 film microstructure to obtain a high PCE. © 2022, The Authors. All rights reserved.

关键词： Selenium compounds

来源：评论

学校读者我要写书评

暂无评论

Conflict Mechanism Analysis Method for Electric Vehicles Participating in Multiple Types of power Grid Ancillary Services

Conflict Mechanism Analysis Method for Electric Vehicles Par...

引用

International Conference on power system technology (powerCON)

作者： Yinjuan Xue Qifang Chen Haiqing Cai Mingchao Xia Haohan Gu School of Electrical Engineering Beijing Jiaotong University Beijing China State Key Laboratory of HVDC Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid National Energy Power Grid Technology R&D Centre Electric Power Research Institute China Southern Power Grid Guangzhou China

As the high-quality flexible resource of the grid, electric vehicles (EVs) can provide multiple auxiliary services for the grid at the same time. However, due to the one-way charging and discharging of EVs, as well as the limitation of power and capacity, which may cause availability conflicts when EVs participate in different auxiliary services simultaneously. This paper focuses on the analysis of the conflict mechanism of EVs participating in the secondary frequency regulation and peak shaving ancillary services at the same time. The impact mechanism between different auxiliary services in this conflict mode is revealed from the two aspects of limit conflict and charging and discharging instruction conflict, and the results of availability conflict of the two types of auxiliary services are verified and analyzed through simulation examples.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Conditional Adversarial Domain Adaption based on Self-attention

Journal of Network Intelligence

引用

Journal of Network Intelligence 2022年第1期7卷 175-188页

作者： Zhao, Li-Quan Zhang, Yu-Peng Teng, Zi-Ming Jiang, Zi-Cong Cui, Ying Kan, Zhong-Feng Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China College of information and communication Jilin University Changchun130012 China Graduate school of Information Science and Electrical Engineering Kyushu University Fukuoka819-0395 Japan Zhuhai Power Supply Bureau Guangdong Electric Power Corporation Zhuhai519000 China Jilin Power Supply Bureau Jilin Electric Power Corporation Jilin132012 China

Transfer learning is a deep learning method. It transforms knowledge in the source domain and feeds it to the target domain to improve the performance of the target domain model. The conditional adversarial domain adaption method is one of a number of transfer learning methods. It uses Resnet as the feature extraction network;however, Resnet can only determine the relationship between local features, and so its feature extraction accuracy is limited. To overcome this problem, a self-attention layer has been designed in order to determine the relationship among all features. This layer is added between the fourth layer and fifth layer of Resnet. Besides, a cross-entropy function is introduced into loss function, and a sigmoid layer is designed and used as the out layer in conditional adversarial domain adaption. These produce gradient disappearance in the deep network, and influence the discriminator training effect. To solve that problem, a least squares function is used as to design the loss function. The new type of loss function does not require the sigmoid function. Using theoretical analysis, we explain how this new loss function can be used to solve the gradient disappearance problem, thus rendering the network structure more stable. We compare our proposed method with other datasets, including Joint Adaptation Networks, adversarial domain adaptation, conditional adversarial domain adaption, Resnet-50, domain-adversarial neural network on imageCLEF-DA, Office-Home, and Office-31. Our simulation results show that the proposed conditional adversarial domain adaption based on self-attention method has the fastest convergence speed and highest accuracy the among different datasets. © 2022, Taiwan Ubiquitous Information CO LTD. All rights reserved.

关键词： Computer vision

来源：评论

学校读者我要写书评

暂无评论

Active Support Performance Test of Grid-connected Photovoltaic system Based on Grid-forming control

Active Support Performance Test of Grid-connected Photovolta...

引用

Intelligent power and systems (ICIPS), International Conference on

作者： Xinze Xi Yun Hu Chao Xing Qi Guo Shoudong Xu Liang Tu Peng He Yihua Zhu Mingzhang Su Chao Luo Yunnan Electric Power Research Institute Kunming China National Energy Power Grid Technology R&D Centre Guangzhou China State Key Laboratory of HVDC Electric Power Research Institute CSG Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Guangzhou China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China

With the continuous increase penetration of new energy, the integration of grid-following (GFL) converter is prone to frequency stability issue, while the utilization of grid-forming (GFM) converter with active support capability has become an inevitable trend in development. In this paper, the model of grid-connected photovoltaic system using GFL/GFM control is established. The support characteristic of GFM is compared and analyzed in different testing scenarios with GFL as the reference: (1) Small disturbance test (2) Large disturbance test (3) Island capability test. Finally, the active support performance of the system is quantitatively analyzed based on corresponding evaluation indexes.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Closed-loop simulation Method of Stability control system Based on Virtual Component technology

Closed-loop Simulation Method of Stability Control System Ba...

引用

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

作者： Qinfeng Ma Yihua Zhu Mingshun Liu Dongxu Chang Qingxin Pu Chengxiang Li Power Dispatching Control Center of Guizhou Power Grid Co. Ltd Guizhou China State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid Guangzhou China National Energy Power Grid Technology R&D Centre Guangzhou China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Guangzhou China

The stability control system is an important means to ensure the safe and stable operation of the power system. In view of the shortcomings of the existing offline/real-time simulation test methods, a closed-loop simulation scheme based on virtual component technology is proposed. The virtual component technology of the stability control device is researched, and the virtualization method of the external hardware interface of the device is designed. On this basis, a closed-loop simulation framework of the stability control system under the offline/real-time simulation test environment is proposed. The functional logic of each component under the framework are analyzed. The calculation and feedback process of the entire closed-loop simulation system are analyzed in depth, which effectively solves the difficulty of simulation analysis and test verification of large-scale stability control system, providing a new method for the research and verification of stability control system strategy.

关键词： Analytical models Process control system integration power system stability control systems Stability analysis Hardware

来源：评论

学校读者我要写书评

暂无评论

reversible in-situ exsolution of Fe catalyst in La0.5Sr1.5Fe1.5Mo0.5O6-δ anode for SOFCs 16

reversible in-situ exsolution of Fe catalyst in La0.5Sr1.5Fe...

引用

16th International Symposium on Solid Oxide Fuel Cells, SOFC 2019

作者： Qi, H. Yang, T. Li, W. Ma, L. Hu, S. Shi, W. Sabolsky, E.M. Zondlo, J. Hart, R. Hackett, G.A. Liu, X. Department of Mechanical and Aerospace Engineering West Virginia University MorgantownWV26506 United States National Energy Technology Laboratory MorgantownWV26505 United States Oak Ridge Institute for Science and Education P.O. Box 117 Oak RidgeTN37830 United States Department of Energy and Power Engineering State Key Laboratory of Control and Simulation of Power System and Generation Equipments Tsinghua University Beijing10083 China GE Global Research Centre NiskayunaNY12309 United States

ISBN: (纸本)9781607688747

In-situ exsolution is widely considered to be an efficient and cost-effective method to enhance the electrochemical performance of a ceramic anode in solid oxide fuel cells (SOFCs). In this study, by controlling the non-stoichiometry of Sr2Fe1.5Mo0.5O6-δ with A-site doping, evenly distributed Fe nano-particles (~100 nm) were obtained on surface of La0.5Sr1.5Fe1.5Mo0.5O6-δ (LSFM) when treated in hydrogen. In a redox environment, excellent exsolution-dissolution reversibility was also demonstrated. Electrical conductivity relaxation (ECR) and electrochemical impedance spectroscopy (EIS) were employed to evaluate the surface reaction kinetics change during exsolution. The surface exchange coefficient (kex) was increased by 1.5 to 2 times with Fe exsolution. Based on distribution of relaxation time (DRT) analysis, the polarization resistance (Rp) associating with surface process was reduced in the first few hours. Both results revealed an enhanced surface reaction kinetics which mainly benefits from the high catalytic activity of exsolved nano-particles to H2 adsorption and dissociation process. © The Electrochemical Society.

关键词： Electrochemical impedance spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Grid-forming control of VSC-HVDC systems Connecting Asynchronous power Grids

Grid-forming Control of VSC-HVDC Systems Connecting Asynchro...

引用

power system and Green energy Conference (PSGEC)

作者： Mingqun Liu Guanming Zeng Xin He Liang Tu Peng He Yihua Zhu Electric Power Research Institute Yunnan Power Grid Co. Ltd. Kunming State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid National Energy Power Grid Technology R&D Centre Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China

ISBN: (数字)9798350365573

ISBN: (纸本)9798350365580

Interconnecting asynchronous power grids with the VSC-HVDC transmission is an important trend. To enhance the weak grid operation performance and grid frequency response capability of the VSC-HVDC system, a novel grid-forming without using the phase-locked-loop is applied in both ends of the VSC-HVDC system. The DC voltage-Active power droop-based grid-synchronization method is utilized. With the proposed method, the sending and the receiving end MMCs perform like a synchronous motor and a synchronous generator, respectively. When the frequency changes in either grid, the system can automatically response to it and change the active power transmission by VSC-HVDC to achieve primary frequency regulation and active frequency support. Finally, the validity of the dual-end grid-forming control is verified based on the simulations in PSCAD/EMTDC.

关键词： power transmission control systems Synchronous motors Market research power grids Synchronous generators Synchronization Phase locked loops Frequency control Grid forming

来源：评论

学校读者我要写书评

暂无评论

A Hybrid Model for Building-level Day Ahead power Load Forecasting Based on Gated Recurrent Unit Networks

A Hybrid Model for Building-level Day Ahead Power Load Forec...

引用

Sustainable power and energy Conference (iSPEC)

作者： Hualu Zhang Boya Deng Jie Shi Key Laboratory of Modern Power System Simulation Control and Green Power New Technology of Ministry of Education Northeast Electric Power University Jilin Jilin Nanjing Nanrui Information Communication Technology Co. Ltd. NARI Group Corporation/State Grid Electric Power Research Institute Nanjing

ISBN: (纸本)9781665414401

Accurate forecasting of day-ahead electrical load is a key to optimize the operation of the integrated energy system (IES) and a fundamental function of the cyber-physical system (CPS) of IES. Due to the characteristics of different features, data collected by CPS often have different sampling frequencies, resulting in mining data trends inadequately when making a load forecast. This paper proposes an GRU-based model to combine historical data with different sampling frequencies in forecasting day-ahead building-level load. First, day-level features are clustered by K-means. Hour-levels features are then partitioned according to clustering results and inputted separately into a gated recurrent unit (GRU) based neural network to capture relationships between external features and load fluctuations. The temporal dependencies of minute-level data are captured by the GRU network directly without any external features. Finally, the least square method is used to combine forecasting results at each hour of two models. The simulation results present that the proposed model performs better than a single model when applying to real-world data.

关键词： Load forecasting simulation Neural networks Training data Predictive models Logic gates Data models

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：