检索结果-内蒙古大学图书馆

11th Frontier Academic Forum of Electrical Engineering, FAFEE 2024

作者： Ma, Pengyu Li, Benliang Zou, Jun State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China State Power Economic Research Institute Beijing102200 China

ISBN: (纸本)9789819787791

With the development of cities, underground tunnels are more and more widely used, and the reinforced concrete in their walls can be used as the natural grounding body of the tunnels. However, underground tunnels have curved structures, multiple cross-sections and deep-buried structures, and the electrical conductivity of the concrete is different from that of the soil, etc., and the traditional analytical method has limitations in calculating the grounding resistance of the tunnels in these cases. In order to satisfy the needs of practical engineering, this paper adopts a numerical method based on the MoM numerical method to analyze the grounding system of underground tunnels with complex geometries and to calculate the grounding resistance of reinforced concrete systems in underground tunnels. In order to assess the difference between the analytical solution and the exact solution, the article introduces a correction factor to measure the ratio between the two. simulations are carried out for real cases, and the results show that the accuracy of the analytical solution can be improved by introducing the correction factor. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： correction factor grounding resistance numerical method Underground tunnels

来源：评论

学校读者我要写书评

暂无评论

Achieving an Accurate Random Process Model for PV power Using Cheap Data:Leveraging the SDE and Public Weather Reports

引用

CSEE Journal of power and Energy systems 2025年第1期11卷 124-135页

作者： Yiwei Qiu Jin Lin Zhipeng Zhou Ningyi Dai Feng Liu Yonghua Song College of Electrical Engineering Sichuan UniversityChengdu610065China State Key Laboratory of the Control and Simulation of Power Systems and Generation Equipment Tsinghua UniversityBeijing 100087China State Key Laboratory of Internet of Things for Smart City University of MacaoMacao999078China Department of Electrical Engineering Tsinghua UniversityBeijing100087China

Stochastic differential equation (SDE)-based random process models of renewable energy sources (RESs) jointly capture evolving probability distribution and temporal correlation in continuous time. It enabled recent studies to remarkably improve performance of power system dynamic uncertainty quantification and optimization. However, considering the non-homogeneous random process nature of PV, there still remains a challenging question: how can a realistic and accurate daily SDE model for PV power be obtained that reflects its weather-dependent and non-Gaussian uncertainty in operation, especially when high-resolution numerical weather prediction (NWP) or sky imager is unavailable for many distributed plants? To fill this gap, this article finds that an accurate SDE model for PV power can be constructed only using the data from low-resolution public weather reports. Specifically, for each day, an hourly parameterized Jacobi diffusion process recreates temporal patterns of PV volatility. Its parameters are mapped from the day's public weather reports to reflect varying weather conditions using a simple learning model. The SDE model jointly captures intraday and intrahour volatility. Statistical examination shows that the proposed approach outperforms a selection of the latest deep learning-based time series models on real-world data collected in Macao.

关键词： Photovoltaic(PV)power random process stochastic differential equation(SDE) stochastic optimization time series modeling uncertainty quantification weather report

来源：评论

学校读者我要写书评

暂无评论

Suppression of Phase Current Ripple and Torque Harmonics in Four-Module PMSM with Asymmetric Mutual Inductance

引用

IEEE Transactions on power Electronics 2025年

作者： Liu, Kaiyuan Li, Chi Zheng, Zedong Li, Yongdong Tsinghua University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Beijing100084 China

In N-module motors, uniform carrier phase shifting (UCPS) by 2π/N between modules can effectively suppress torque harmonics caused by high-frequency switching of power devices. In multi-module motors with fractional-slot concentrated winding, the mutual inductance between adjacent windings is higher than that between non-adjacent windings. Although the conventional UCPS can reduce the torque sideband harmonics synthesized by the four modules, this asymmetric mutual inductance (AMI) paradoxically increases phase current ripple in each sub-module, leading to higher system losses. Aiming at this problem, this paper derives the mathematical model of N-module motor with AMI, analyzes the limitations of the traditional UCPS method that increases the phase current ripple. For different optimization objectives, two carrier phaseshifting angle optimized strategies are proposed to achieve integrated suppression of torque sideband harmonics and intramodule phase current ripples, with a genetic algorithm improving optimization speed. A threshold coefficient is introduced to achieve a tradeoff between phase current ripple and q-axis current harmonics, which can be adjusted to prioritize objectives based on user requirements. To enhance algorithm adaptability, the paper further investigates model variations under uneven torque distribution in sub-healthy states and proposes an improved comprehensive optimization algorithm, limiting torque sideband harmonics and current ripple in both healthy and sub-healthy conditions. Finally, the proposed algorithm is validated experimentally by a four-module permanent magnet synchronous motor. © 2025 IEEE.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

Semi-empirical equivalent circuit model and evaluation of energy losses for alkaline electrolysis stack in dynamic operations

引用

International Journal of Hydrogen Energy 2025年 138卷 859-873页

作者： Sha, LianDong Lin, Jin Qi, Ruomei Li, Qinghui Li, Wenying Lin, Ruixiao Gao, Danhui Li, Hang Li, Xiaolong Yang, Chenxi Song, Yonghua State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing 100084 China Tsinghua-Sichuan Energy Internet Research Institute Chengdu 610213 China School of Chemistry and Chemical Engineering Southwest Petroleum University Chengdu 610213 China School of Nuclear Science and Engineering North China Electric Power University Beijing 100084 China State Key Laboratory of Internet of Things for Smart City University of Macau 999078 Macao

In various applications of alkaline water electrolysis (AWE) for hydrogen production, the efficiency of AWE stacks is a critical concern. Emerging applications involve significant dynamic operations, necessitating the evaluation of their impact on stack efficiency. However, a quantitative understanding of the power losses within AWE stacks under dynamic conditions remains limited. A significant research challenge exists in the development of models for AWE stacks that can accommodate dynamic operating conditions, and there is a need for a systematic approach to classify and quantify energy losses within the stack. This paper presents a quantitative assessment method for losses in AWE stacks based on a semi-empirical equivalent circuit model (SECM). The losses within the AWE stack are categorized into four types based on their generation mechanisms: overpotential losses, shunt current losses, non-Faradaic losses, and electrochemical cycling losses (cycling losses for short). Using experimental data from 5 MW and 10 kW AWE stacks, the parameters of the SECM observer are identified through a stepwise data-driven approach, resulting in a mean square error of less than 46.4 mV for 5 MW stack and 80.9 mV for 10 kW stack. The constructed SECM observer is employed to simulate the proportion of various losses under different dynamic operating conditions. This paper focuses on the efficiency and loss behaviors of AWE stacks under multi-stack switching strategies. Case studies demonstrate that the current range, ramp rate, regulation period, and duty cycle significantly influence the four types of losses. Based on the SECM observer, recommended parameters for multi-stack switching are provided. This work contributes to accurate assessment of AWE stack efficiency under dynamic operations and provides a methodology for designing AWE stack operating strategies. © 2025 Hydrogen Energy Publications LLC

关键词： Alkaline water electrolysis stack Dynamic operation Efficiency Electrochemical cycling losses Equivalent circuit model Multi-stack switching strategies

来源：评论

学校读者我要写书评

暂无评论

Linear Precoding Design for MIMO-PLC systems

引用

Tsinghua Science and Technology 2015年第2期20卷 155-163页

作者： Jisheng Peng the State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua Uinversity

In this paper, we consider the design of linear precoding in Multiple Input Multiple Output （MIMO） power Line Communication （PLC） systems with finite-alphabet input. First, we derive mutual information of MIMO-PLC systems with impulsive noise. Considering the non-concavity of the objective function and the low-cost requirement of PLC systems, we choose the lower bound of the mutual information as the objective function. Subsequently, we propose a novel approach to design the precoding scheme to reduce computational complexity. Specifically, our work primarily includes the following two contributions：（1） We design the right unitary matrix that is a product of two fixed unitary matrices, which only depends on the modulation mode. Hence, the results can be saved and require less computations. （2） For the power allocation matrix, we first reduce the space of power allocation using constraints of the optimal power allocation policy. Consequently, we propose a non-linear search method to obtain the optimal power allocation in small space. In regards to the computational complexity of the analysis, we conclude that the proposed precoding matrix design scheme has low complexity and is easy to implement. Moreover, the numerical results are proven to demonstrate the performance of the proposed precoding design scheme.

关键词： precoding design MIMO-PLC impulsive noise finite-alphabet input

来源：评论

学校读者我要写书评

暂无评论

Simplified mathematical model of inter-turn short circuit of field windings in hydro-generators and its application

引用

Science China(Technological Sciences) 2013年第4期56卷 898-909页

作者： HAO LiangLiang WU JunYong SUN YuGuang WANG XiangHeng School of Electrical Engineering Beijing Jiaotong University State Key Lab of Control and Simulation of Power Systems and Generation Equipment Tsinghua University

Inter-turn short circuit of field windings is a common electrical fault of *** is an important method of investigating the fault and providing data support for fault ***,huge numbers of pole pairs and damper loops in large hydro-generators would lead to lengthy calculation time,hindering scientific research and engineering *** deal with this problem,we analyze a theoretical basis for a damper winding simplified model and then propose an equivalent treatment *** the analysis of steady-state current harmonic characteristics of generators with different stator winding configurations during the fault,the simplified models suitable for steady-state calculation are derived from two aspects,namely,additional rotor harmonic current frequency characteristics and the relationship of the amplitude as well as the phase of each branch current of the *** calculation and experimental results of the two simplified models are then compared to verify the models' correctness.A calculation example of the Three Gorges left bank VGS generator shows few deviations between the calculation results of the simplified model and the original ***,the calculation time using the simplified model is 1/1500 that using the original model,which provides a more effective tool for on-line fault ***,the sensitivity-verification application of the fault-monitoring scheme based on the stator steady-state unbalanced current RMS is *** result shows that the scheme can monitor two-turn short circuits of field windings in the Three Gorges generator and provide high sensitivity.

关键词： hydro-generator field windings inter-turn short circuit simplified model on-line monitoring

来源：评论

学校读者我要写书评

暂无评论

Estimation of the electromechanical characteristics of power systems based on a revised stochastic subspace method and the stabilization diagram

引用

Science China(Technological Sciences) 2012年第6期55卷 1677-1687页

作者： NI JingMin SHEN Chen LIU Feng State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Beijing 100084China

Estimating low-frequency oscillation modes and the corresponding mode shapes based on ambient data from WAMS measurements has a promising prospect in power system analysis and *** on the stochastic subspace method,this paper proposes a revised stochastic subspace method by introducing reference channels,which can estimate the modes and the mode shapes simultaneously with great computational ***,the accuracy of the estimated results is not *** discriminate the real modes from the spurious ones,the stabilization diagram is introduced.A novel algorithm is designed to deal with the stabilization diagram which can detect the real modes *** conducted on the IEEE-118 system indicate that the proposed method has good performance in terms of both computational efficiency and accuracy,and has the potential of being used on-line.

关键词： electromechanical oscillation ambient data stochastic subspace method reference channels stabilization diagram

来源：评论

学校读者我要写书评

暂无评论

Effect of Different Arresters on Switching Overvoltages in UHV Transmission Lines

引用

Tsinghua Science and Technology 2010年第3期15卷 325-328页

作者：杨鹏程陈水明何金良 State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical EngineeringTsinghua University

The amplitude of switching overvoltages is a key factor for designing the insulation of UHV equipment. The effect of different arresters needs to be studied, since installing arresters is an important way to suppress switching overvoltages in UHV transmission lines. Switching overvoltages on the 1000 kV Huainan-Huxi double-circuit transmission line were simulated for different operating modes and different arrester designs using the electromagnetic transient program PSCAD/EMTDC. With parallel resistors, the switching overvoltages are less than 1.70 p.u. （1.0 p.u.=1100×√ 2 /√3 kV）. If the arrestors are better, the switching overvoltages can be reduced even lower to 1.55 p.u. Without parallel resistors, the arresters can reduce three-phase energizing overvoltages to 1.70 p.u, while the single-phase reclosing overvoltages still exceed the limit. The results show that the parallel resistors cannot be eliminated if the arresters are only installed at each end of the transmission line. Also, better quality arresters significantly lower the switching overvoltages.

关键词： UHV double-circuit transmission line switching overvoltages arresters

来源：评论

学校读者我要写书评

暂无评论

Recent advances on smart grid technology and renewable energy integration

引用

Science China(Technological Sciences) 2013年第12期56卷 3040-3048页

作者： MEI ShengWei CHEN LaiJun State Key Lab of Control and Simulation of Power Systems and Generation Equipments (Dept. of Electrical Engineering Tsinghua University)

With the integration of renewable energy generations and other related changes,the smart grid,or the future electric power system,is confronted with new challenges and ***,it is a promising subject in electrical engineering and much work has been done on *** paper reviews the recent advances on the technologies of smart grid and renewable energy integration,from the aspects of modeling,simulation,protection and control,stability,operation,and planning.

关键词： smart grid renewable energy integration modeling simulation protection and control stability operation planning

来源：评论

学校读者我要写书评

暂无评论

Wavelet-based data compression for wide-area measurement data of oscillations

引用

Journal of Modern power systems and Clean Energy 2018年第6期6卷 1128-1140页

作者： Lin CHENG Xinchi JI Fang ZHANG He HUANG Song GAO State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University State Grid Jiangsu Electric Power Company

This paper proposes a wavelet-based data compression method to compress the recorded data of oscillations in power systems for wide-area measurement systems. Actual recorded oscillations and simulated oscillations are compressed and reconstructed by the waveletbased data compression method to select the best wavelet functions and decomposition scales according to the criterion of the minimum compression distortion composite index, for a balanced consideration of compression performance and reconstruction accuracy. Based on the selections, the relationship between the oscillation frequency and the corresponding optimal wavelet and scale is discussed, and a piecewise linear model of the base-2 logarithm of the frequency and the order of the wavelet is developed, in which different pieces represent different scales. As a result, the wavelet function and decomposition scale can be selected according to the oscillation frequency. Compared with the wavelet-based data compression method with a fixed wavelet scale for disturbance signals and the real-time data compression method based on exception compression and swing door trending for oscillations, the proposed method can provide high compression ratios and low distortion rates.

关键词： Data compression Oscillation Wavelet transform Wide-area measurement system(WAMS)

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：