检索结果-内蒙古大学图书馆

A fast algorithm for manipulation control process of distribution system planning solution

Journal of Modern power systems and Clean Energy 2019年第6期7卷 1547-1558页

作者： Lin CHENG Yuxiang WAN Liting TIAN Fang ZHANG State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijingChina School of Electrical Engineering Beijing Jiaotong UniversityBeijingChina

Better flexibility and controllability have been introduced into distribution system with the development of new loads and *** a consequence,the connotations and tools for evaluating the planning solution need to be further *** paper proposes a fast algorithm to quantify steady-state voltages and load profiles in distribution system by simulating the manipulation control process of controllable resources,taking the efficiency and ease of use into *** this method,a complex distribution system is decoupled into several simple parts according to the ports of the DC ***,to achieve the qualified voltages and load profiles,the manipulation details of controllable resources are simulated following a certain control sequence in each ***,the analysis results of each part are matched and filtered to obtain a complete *** types of the most commonly controllable resources are considered in this *** effectiveness of the proposed method is demonstrated through a case study based on field data from an actual distribution system.

关键词： controllable resources Distribution system DC interlink Planning Manipulation control process

来源：评论

学校读者我要写书评

暂无评论

Optimal Scheduling of Active-Reactive power for PV-BES system Considering Voltage Support and Frequency Regulation 50

Optimal Scheduling of Active-Reactive Power for PV-BES Syste...

引用

50th Annual Conference of the IEEE Industrial Electronics Society, IECON 2024

作者： Zhang, Jiamei Sun, Kai Department of Electrical Engineering State Key Laboratory of Power System Operation and Control Tsinghua University Beijing China

ISBN: (纸本)9781665464543

The voltage support capability of renewable resources (RES) is emphasized by grid codes for stable and secure operation faced with grid faults. However, there is another problem occurs when the penetration of RES is boosting. The capability occupation due to injected power for voltage support leads to the decrease of output power for loads, which may result in frequency issues when the inertia of the system decreases. To guarantee the voltage and frequency security during fault ride through (FRT) process, this paper proposes an optimal scheduling scheme for PV-BES system considering voltage support and frequency regulation. In the optimal model, in order to map the voltage and frequency constraints into power constraints, the evaluation model of required injected power for voltage support is formulated firstly. Based on center of inertia theorem and time scale characteristics of FRT, the frequency deviation is represented by distributed generator (DG) adjustment. The voltage and frequency constraint are incorporated into the optimal scheduling model and the quasi-steady-state of the PV-BES system during FRT can be analyzed. The proposed method is fully tested, and the results demonstrate that with the proposed method, the voltage and frequency security can be well guaranteed. © 2024 IEEE.

关键词： Renewable energy

来源：评论

学校读者我要写书评

暂无评论

A Modulation Scheme of CLLC Converters for Bidirectional power Transfer with Reduced Switching Frequency Range

A Modulation Scheme of CLLC Converters for Bidirectional Pow...

引用

2024 IEEE Energy Conversion Congress and Exposition, ECCE 2024

作者： Wang, Leheng Chen, Huan Sun, Kai Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing China

ISBN: (纸本)9798350376067

CLLC converters are broadly used in battery energy storage systems (BESS), where the capabilities of bidirectional operation and voltage regulation are desired. In the existing bidirectional power transfer scheme, pulse frequency modulation (PFM) is used to realize the reciprocal gain of forward and backward directions. It leads to not only large frequency modulation range but also asymmetric transfer characteristics. In this paper, a novel modulation scheme of CLLC converters for bidirectional power transfer is proposed. In the proposed backward power transfer scheme, the driving signals of primary and secondary-side switches are aligned at the falling-edge, which brings about symmetrical characteristics as forward scheme. This symmetry further ensures the identical switching frequency in both directions, which simplifies parameter design, minimizes switching frequency range, and improves efficiency. A 10-kW prototype is built and the experimental results validate the effectiveness of the proposed scheme, offering potential for cost-effective and efficient applications. © 2024 IEEE.

关键词： Switching frequency

来源：评论

学校读者我要写书评

暂无评论

Optimal Design of Full-Bridge Three-Level LLC Converter Based on Time-Domain Analysis 2

Optimal Design of Full-Bridge Three-Level LLC Converter Base...

引用

2nd IEEE International power Electronics and Application Symposium, PEAS 2023

作者： Liu, Zengyang Sun, Kai Yi, Zheyuan Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing China

ISBN: (纸本)9798350313765

Fully DC wind turbine generator system is a promising substitute for conventional AC one. In the system, the LLC step-up converter plays a key role. Mode analysis and time-domain expressions can provide more accurate estimation of the resonant performance than the conventional First Harmonic Analysis method. The circuit works at different modes as the load rate varies. This paper categorizes these resonant behaviors into four modes, with time-domain expressions of each mode obtained. The variation regular of these modes is given and is applied in the program to realize recognizing the working mode automatically. The simulation and experiment have verified the effectiveness of the proposed method. © 2023 IEEE.

关键词： fully DC wind turbine generator system LLC converter mode analysis Pareto Front optimization time-domain expression

来源：评论

学校读者我要写书评

暂无评论

Short-Term Photovoltaic Prediction Based on Transfer Learning and LSTM 7

Short-Term Photovoltaic Prediction Based on Transfer Learnin...

引用

7th IEEE Conference on Energy Internet and Energy system Integration, EI2 2023

作者： Zhang, Tianyu Zheng, Kedi Chen, Qixin Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing China

ISBN: (纸本)9798350345094

With the proposal of carbon peaking and carbon neutrality goals, the proportion of renewable energy generation continues to increase and the number of new photovoltaic power stations is growing rapidly. Accurate photovoltaic power prediction is of great significance for the safe, stable and operation of power system. In order to solve the problem of insufficient historical data of newly constructed PV power plants, this paper proposes a short-term PV power prediction model based on Long Short Term Memory and transfer learning. The model uses meteorological data, numerical weather forecast data and PV power as features. According to the transfer learning theory, the Long Short Term Memory model is pre-trained using the historical data of other previously-built PV power plants, and then a small amount of local operation data is used to fine-adjust the model. Case study based on Hebei open source photovoltaic and meteorological data set proves that the proposed transfer learning model can effectively improve the short-term PV power prediction accuracy, and the MAPE can be improved by up to 15%. © 2023 IEEE.

关键词： Long short-term memory

来源：评论

学校读者我要写书评

暂无评论

Influence of Thermal Conductivity of Multi-scale Particles Epoxy Composites on High-Frequency electrical Insulation Property 5

Influence of Thermal Conductivity of Multi-scale Particles E...

引用

5th IEEE International Conference on Dielectrics, ICD 2024

作者： Song, Yan-Hui Dang, Zhi-Min Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing China

ISBN: (纸本)9798350308976

Epoxy, with excellent electrical insulation properties, processing performance, and low price, is commonly used for transformers (110kV and below) and power electronic transformers (high-frequency transformers) as the primary insulating material. Since the thermal conductivity of epoxy resins is only 0.2 W/(m·K), the electrical insulation properties decline significantly at high frequency. Preparing epoxy composites with high thermal conductivity and excellent electrical insulation at high frequencies is a great challenge for industrial production. It is considered that SiO2 (9 eV), BN (5.9 eV), and Al2O3 (7.2-8.8 eV) are thermally conductive particles with good electrical insulation properties. The materials filled with different micron-scale particles have higher thermal conductivity than the nanofilled materials. In this study, 5 μm SiO2, 25 μm BN, and 40 μm Al2O3 were used as fillers, and the filler ratios were calculated according to the Dinger-Funk model, focusing on the effects of the variation of filler content on thermal conductivity and electrical insulation properties. The thermal conductivity of the epoxy composites improved with the increase of filler content up to 1.003 W/(m·K), while the AC breakdown field strength gradually decreased. However, the breakdown time at 20 kHz, 35 kV/mm bipolar square wave appeared to increase and then decrease with the increase of content. Therefore, the optimum content of fillers allows the preparation of efficient epoxy composites as insulating materials for power electronic transformers. This study provides ideas for designing thermally conductive composites operating at high frequency and high voltage fields. © 2024 IEEE.

关键词： epoxy resin high frequency bipolar square wave inorganic particle compounding thermal conductive electrical insulation

来源：评论

学校读者我要写书评

暂无评论

Regional wind power forecasting model with NWP grid dataoptimized

引用

Frontiers in Energy 2017年第2期11卷 175-183页

作者： Zhao WANG Weisheng WANG Bo WANG State Key Laboratory of Operation and Control of Renewable Energy &Storage Systems China Electric Power Research Institute Beijing100192 China Department of Electrical Engineering TsinghuaUniversity Beijing 100084 China State Key Laboratory of Operation and Control of Renewable Energy &Storage Systems China Electric Power Research Institute Beijing100192 China

Unlike the traditional fossil energy, wind, as the clean renewable energy, can reduce the emission of the greenhouse gas. To take full advantage of the environmental benefits of wind energy, wind power forecasting has to be studied to overcome the troubles brought by the variable nature of wind. power forecasting for regional wind farm groups is the problem that many power system operators care about. The high-dimensional feature sets with redundant information are frequently encountered when dealing with this problem. In this paper, two kinds of feature set construction methods are proposed which can achieve the proper feature set either by selecting the subsets or by transforming the original variables with specific combinations. The former method selects the subset according to the criterion of minimal-redundancy-maximal-relevance (mRMR), while the latter does so based on the method of principal component analysis (PCA). A locally weighted learning method is also proposed to utilize the processed feature set to produce the power forecast results. The proposed model is simple and easy to use with parameters optimized automatically. Finally, a case study of 28 wind farms in East China is provided to verify the effectiveness of the proposed method.

关键词： regional wind power forecasting feature set minimal-redundancy-maximal-relevance (mRMR) principal component analysis (PCA) locally weighted learning model

来源：评论

学校读者我要写书评

暂无评论

Low-Carbon Dispatching for Virtual power Plant with Aggregated Distributed Energy Storage Considering Spatiotemporal Distribution of Cleanness Value

引用

Journal of Modern power systems and Clean Energy 2024年第2期12卷 346-358页

作者： Hongchao Gao Tai Jin Guanxiong Wang Qixin Chen Chongqing Kang Jingkai Zhu State Key Laboratory of Power System Operation and Control Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Sichuan Energy Internet Research Institute Tsinghua University Chengdu 200016China Power Dispatching and Control Center of Shanghai Municipal Electric Power Company Shanghai 200122China IEEE

The scale of distributed energy resources is increasing,but imperfect business models and value transmission mechanisms lead to low utilization ratio and poor *** address this issue,the concept of cleanness value of distributed energy storage(DES)is proposed,and the spatiotemporal distribution mechanism is discussed from the perspectives of electrical energy and *** on this,an evaluation system for the environmental benefits of DES is constructed to balance the interests between the aggregator and the power system ***,an optimal low-carbon dispatching for a virtual power plant(VPP)with aggregated DES is constructed,where-in energy value and cleanness value are both *** achieve the goal,a green attribute labeling method is used to establish a correlation constraint between the nodal carbon potential of the distribution network(DN)and DES behavior,but as a cost,it brings multiple nonlinear ***,a solution method based on the convex envelope(CE)linear re-construction method is proposed for the multivariate nonlinear programming problem,thereby improving solution efficiency and ***,the simulation verification based on the IEEE 33-bus DN is *** simulation results show that the multidimensional value recognition of DES motivates the willingness of resource users to ***,resolving the impact of DES on the nodal carbon potential can effectively alleviate overcompensation of the cleanness value.

关键词： Distributed energy storage virtual power plant(VPP) spatiotemporal distribution low-carbon dispatching

来源：评论

学校读者我要写书评

暂无评论

Effects of manganese dioxide additives on the electrical characteristics of Al-doped ZnO varistors

引用

Science China(Technological Sciences) 2011年第8期54卷 2204-2208页

作者： LONG WangCheng HU Jun HE JinLiang LIU Jun ZENG Rong State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China

The effects of manganese dioxide (MnO 2 ) additives on the electrical characteristics of the Al-doped ZnO varistors are investigated. The leakage current densities of the samples decrease first and then increase again with the increase of the amount of MnO 2 additives. Correspondingly, the nonlinear coefficients of the samples keep on increasing and then decrease. In addition, the donor densities increase monotonously with the amount of the doped MnO 2 increasing. The effects of MnO 2 additives on the electrical characteristics of the samples are different from the conclusion of previous literatures. The reasons of the distinct effects are supposed to be related with the donor and interface state densities of the samples.

关键词： ZnO varistots manganese dioxide electrical characteristics low residual voltage ratio simulation

来源：评论

学校读者我要写书评

暂无评论

Forecasted Scenarios of Regional Wind Farms Based on Regular Vine Copulas

引用

Journal of Modern power systems and Clean Energy 2020年第1期8卷 77-85页

作者： Zhao Wang Weisheng Wang Chun Liu Bo Wang State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijingChina Department of Electrical Engineering Tsinghua UniversityBeijingChina

Owing to the uncertainty and volatility of wind energy,forecasted wind power scenarios with proper spatio-temporal correlations are needed in various decision-making problems involving power *** this study,forecasted scenarios are generated from an estimated multi-variate distribution of multiple regional wind *** to the theory of copulas,marginal distributions and the dependence structure of multi-variate distribution are modeled through the proposed distance-weighted kernel density estimation method and the regular vine(R-vine)copula,*** to the flexibility of decomposing correlations of high dimensions into different types of pair-copulas,the R-vine copula provides more accurate results in describing the complicated dependence of wind *** the case of 26 wind farms located in East China,highquality forecasted scenarios as well as the corresponding probabilistic forecasting and point forecasting results are obtained using the proposed method,and the results are evaluated using a comprehensive verification framework.

关键词： Forecasted scenarios wind power distanceweighted kernel density estimation(KDE) regular vine(R-vine)copula spatio-temporal correlation

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：