检索结果-内蒙古大学图书馆

Energy Management for Households Considering Uncertainty in Solar Irradiance With Various Probability Distribution

JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY 2019年第5期14卷 1943-1956页

作者： Liu, Jingwen Wang, Wei Zhang, Yumin Xu, Xingming Shandong Univ Sci & Technol Sch Machine & Elect Engn Tai An 271019 Shandong Peoples R China Shandong Univ Minist Educ Key Lab Power Syst Intelligent Dispatch & Control Jinan 250061 Shandong Peoples R China

The electricity load scheduling problem in a household with roof-top photovoltaic (PV) system can efficiently reduce customers' payments. Compared with previous works in which common flat rate (CFR) has been used, this paper study the case where the time-of-use pricing (TOUP) is adopt. Two conditional equations are constructed for different gains of customers. This is caused by different power direction between the household and the main grid. The two conditional gains equations for the customer are transformed into linear equations by introducing auxiliary variables and linear expression techniques. As a result, established mathematical model to maximize gains for customer is transformed into a mixed integer linear programing (MILP) problem. Thus the resulting MILP model can be easily solved by existing powerful commercial solver. The adjustable and rating power consumption property of appliances are both considered. There are two different mathematic models for them respectively. The impact of reduction of the maximum exchange power between the household and the main grid on gains of the customer, gains of the main grid, load demand during off-peak time and energy exported to the main grid is also studied. The validity and feasibility of the proposed model is illustrated by the case studies.

关键词： Smart household PV system Optimal residential load control Time-of-using pricing

来源：评论

学校读者我要写书评

暂无评论

Source-Grid-Load Synergized Transmission Planning

Source-Grid-Load Synergized Transmission Planning

引用

Chinese Automation Congress (CAC)

作者： Donglei Sun Qingzhi Jian Xueliang Li Long Zhao Yiqun Wang Dong Liu Ying Mu Xueshan Han Mingqiang Wang Economic & Technology Research Institute State Grid Shandong Electric Power Company Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan China

ISBN: (数字)9781728176871

ISBN: (纸本)9781728176888

A source-grid-load synergized transmission planning method is proposed to deal with the large-scale wind power accommodation problem. Through integration of the optimization of demand side response mechanism and thermal power units' flexibility reformation schemes into transmission planning optimization model, the source-grid-load flexibility resources of power systems are optimized to promote wind power utilization. A joint optimization mathematical model for the thermal power units' flexibility reformation schemes, demand side response mechanism and optimization of transmission network is constructed. The proposed mathematical model is transformed into a mixed-integer linear programming model and solved by mixed-integer linear programming algorithm. Case studies are conducted to illustrate the effectiveness of the proposed source-grid-load synergized transmission planning method, and the numerical results show that the proposed method can guarantee the expected wind power utilization.

关键词： Planning Generators power transmission lines Mathematical model Investment power grids Wind power generation

来源：评论

学校读者我要写书评

暂无评论

Estimating the Wind power Integration Threshold Considering Electro-Thermal Coupling of Overhead Transmission Lines

引用

IEEE TRANSACTIONS ON power systemS 2019年第5期34卷 3349-3358页

作者： Dong, Xiaoming Kang, Chongqing Ding, Yuanyuan Wang, Chengfu Shandong Univ Sch Elect Engn Key Lab Power Syst Intelligent Dispatch & Control Minist Educ Jinan 250061 Shandong Peoples R China Tsinghua Univ Elect Engn Dept Beijing 100084 Peoples R China

With regard to wind farms connected to themain system via dedicated overhead transmission lines, the available wind power absorbed by the system relies on not only the power generation capacity but also the power transmission threshold. Thus, this study centers on the close relationship between environmental conditions and power transfer limits that involve the thermal limit and steady-state stability limit. Simultaneous equations representing both overhead conductors' heat balance and power transmission operation are established. In addition, formulations of the maximum transmission power for the steady-state stability limit are derived and then expressed as functions of environmental factors and the line length. The presented approach allows one to analyze the threshold considering not only the thermal limit but also the steady-state stability limit, which could be remarkably different under certain environmental and transmission distance conditions. Then, a scheme to identify the primary limitation and obtain the corresponding threshold value is proposed. Moreover, a simple treatment of wind speed correlation is deployed because of the close distance between a wind farm and its tie-line. Case studies demonstrate that, for a certain wind speed level, the process of transmission rather than generation could become the key factor determining the threshold value.

关键词： Wind power integration electro-thermal coupling power transfer limit thermal limit steady-state stability limit overhead transmission line

来源：评论

学校读者我要写书评

暂无评论

Longitudinal Protection Method based on Voltage Waveform Comparison for AC / DC Hybrid system

Longitudinal Protection Method based on Voltage Waveform Com...

引用

IEEE/IAS Industrial and Commercial power system Asia (I&CPS Asia)

作者： Hongzhe Zhang Wei Cong Hao Kong Ming Chen Zhen Wei Ministry of Education Key Laboratory of Power System Intelligent Dispatch and Control (Shandong University) Jinan China Qingdao Power Supply Company State Grid Shandong Electric Power Company Qingdao China

ISBN: (数字)9781728143033

ISBN: (纸本)9781728143040

When the tie line of the AC/DC hybrid system fails, the change of the electrical quantity on the inverter side is different from that of the traditional infinite AC power source. Sensitivity and reliability of traditional relay protection methods will be affected. A longitudinal protection method for AC / DC hybrid system based on voltage waveform comparison is proposed. The method bases on the conclusion that the waveform characteristics of the reference voltage and the measuring voltage are different in the case of internal and external faults, roughly determine the fault location through the Pearson correlation coefficient. Use longitudinal protection logic to give more accurate judgment results. The simulation results of PSCAD model show that the scheme in this paper can accurately identify the fault of the tie line of the AC/DC hybrid system, and has high reliability and good applicability.

关键词： Voltage measurement Mathematical model Hybrid power systems Inverters Sensitivity Fault location

来源：评论

学校读者我要写书评

暂无评论

Solar power Ramp Event Forewarning With Limited Historical Observations 55

Solar Power Ramp Event Forewarning With Limited Historical O...

引用

55th Annual IEEE/IAS Industrial and Commercial power systems Technical Conference (ICPS)

作者： Zhu, Wenli Zhang, Li Yang, Ming Wang, Bo Shandong Univ Key Lab Power Syst Intelligent Dispatch & Control Jinan 250000 Shandong Peoples R China China Elect Power Res Inst Grade Key Lab Operat & Control Renewable Energy & Beijing 100192 Peoples R China

ISBN: (纸本)9781538675526

Timely and accurate forewarning of solar power ramp events (SPREs) is crucial for a power system operation. In this article, a novel forewarning method for SPREs is proposed based on credal network (CN) and imprecise Dirichlet model (IDM). A new expression of SPRE is proposed, which focuses on the power change caused by meteorological fluctuation. Considering that the single-valued probability may not provide convincing results in case of insufficient ramp event records, probability interval is adopted to reflect the ambiguous correlation between SPREs and meteorological conditions. The meteorological evidences are mapped to ramp events by a CN to enhance the sensitivity of SPRE identification. The structure of the CN is established by the learning algorithm with respect to the relations between SPRE and meteorological conditions, as well as different meteorological conditions. Furthermore, an extended IDM is developed to estimate the interval-valued parameters in the CN. Then, a credal classifier is established to output the ramp forewarning result. The effectiveness of the proposed method is verified through case studies, and obvious improvement on the accuracy of ramp forewarning can be seen.

关键词： Conditional probability credal classification credal network (CN) forecast model imprecise Dirichlet model (IDM) imprecise probability ramp detection ramp forewarning ramp rate solar power ramp event (SPRE)

来源：评论

学校读者我要写书评

暂无评论

An optimal control and sizing strategy for a coordinated WTG-ES system to provide frequency support

引用

INTERNATIONAL JOURNAL OF ELECTRICAL power & ENERGY systemS 2019年第0期113卷 251-263页

作者： Peng, Bo Zhang, Feng Liang, Jun Ding, Lei Wu, Qiuwei Shandong Univ Key Lab Power Syst Intelligent Dispatch & Control Minist Educ 17923 Jingshi Rd Jinan 250061 Shandong Peoples R China Tech Univ Denmark DTU Dept Elect Engn Ctr Elect Power & Energy CEE DK-2800 Lyngby Denmark

In power grids with large wind power integration, long-term wind turbine generator (WTG) de-loading to provide frequency reserves will greatly constrain the economic benefits of a wind farm (WF). Although energy storage (ES) often cooperates with the WF as a combined system to improve the frequency regulation performance, the coordination control inside the combined system and the trade-offs between the expensive investment costs of the ES, the long-term de-loading costs of the WF and the frequency regulation requirements should be further studied. Therefore, in this paper, a fuzzy-based coordinated control and sizing strategy is proposed to achieve dynamic cooperation inside the combined WTG-ES system and optimize the economic performance of the combined system for providing frequency support power. The fuzzy controller is designed to allocate the frequency regulation demand with considering the operation state and the frequency support capability of the WTG-ES system and the type of frequency incidents. Under the proposed control strategy, the WTG can operate at a rate closer to the maximum power point instead of having to maintain a large power reserve level for frequency support;SOC of the ES is separated into several sections with different features and operational rules to make full use of the ES energy capacity and constrain the SOC limit violation problems effectively. Subsequently, based on the proposed coordinated control strategy, an optimization model is presented that determines the optimal WTG de-loading level in different time intervals, ES rating powers and energy capacity, with the objective of minimizing the operation and frequency regulation costs of the combined WTG-ES system. The optimization model is solved by an improved PSO algorithm. Finally, case studies using actual wind power generation and frequency data were conducted to validate the performance of the proposed control and sizing strategy.

关键词： WTG ES Frequency support Reserve Fuzzy controller Optimal sizing

来源：评论

学校读者我要写书评

暂无评论

Robust distributed state estimation of active distribution networks considering communication failures

引用

INTERNATIONAL JOURNAL OF ELECTRICAL power & ENERGY systemS 2020年第0期118卷 105732-000页

作者： Zhang, Tingting Yuan, Peiran Du, Yaxin Zhang, Wen Chen, Jian Shandong Univ Sch Elect Engn Key Lab Power Syst Intelligent Dispatch & Control Minist Educ Jinan 250061 Peoples R China State Grid Langfang Power Supply Co Langfang 065000 Peoples R China

Due to the large scale and three-phase unbalance problem of active distribution networks (ADNs), traditional centralized state estimation (CSE) cannot meet the requirements on estimation accuracy and efficiency for real-time analysis and control of distribution systems. This paper presents a novel consensus-based coordination distributed state estimation (CC-DSE) approach considering communication failures in ADNs. A network partition approach coupled with placement of phasor measurement units (PMUs), which is based on topology analysis, is firstly executed to divide the large-scale distribution network into several sub-regions. Then, the local state estimation (SE) of each sub-region is executed in parallel by improved weighted least squares (WLS) method with revising weights adaptive to residuals without changing the initial objective function, which can mitigate the negative effect of inner-region communication failures. The data coordination is embedded in the iteration of improved WLS of each sub-region estimation by consensus algorithm, which is robust to data missing and bad data caused by inter-region communication failures. The CC-DSE has better performance in accuracy, efficiency and robustness compared with CSE and distributed state estimation (DSE), which is demonstrated by the simulation results of the unbalanced IEEE 123 bus distribution network.

关键词： Communication failures Consensus-based coordination Network partition PMUs Robust distributed state estimation

来源：评论

学校读者我要写书评

暂无评论

Error assessment method of electromechanical-electromagnetic hybrid simulation

Error assessment method of electromechanical-electromagnetic...

引用

作者： Zheng, Zewen Zhang, Hengxu Zheng, Weijie Li, Hao Key Laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education Shandong University Jinan China China Electric Power Research Institute Beijing China

With ultra high voltage direct current (UHVDC) and flexible alternating current transmission systems (FACTS) have been widely applied in power system, the AC/DC power grid is constantly extending which makes its composition more complicated. The independent electromechanical transient simulation and electromagnetic transient simulation cannot meet the need of rapidly developing modern power system in simulation technology. Electromechanical-electromagnetic hybrid simulation not only has the advantages of analysing large systems, but also accurate description of power electronic components. Analysing errors in hybrid simulations can help them to quantitatively analyse different hybrid simulation interface technologies to optimise simulation settings. Concerned fault types, fault location, and point fault cleaning time, an electromechanical-electromagnetic hybrid simulation scenarios probabilistic model based on Monte Carlo is put forward. Then adopt Prony method to quantitatively analyse the hybrid simulation errors. Through a typical example of UHVDC power grid in Shandong province, the error evaluation method of the hybrid simulation is demonstrated in detail. The research shows that this kind of assessment method can well analyse the numerical validity of hybrid simulation. © 2019 Institution of Engineering and *** right reserved.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

An Improved Chimp Optimization Algorithm for Short-term Hydrothermal Scheduling

IAENG International Journal of Computer Science

引用

IAENG International Journal of Computer Science 2022年第3期49卷 666页

作者： Chen, Gonggui Wang, Shumin He, Yongsheng Shang, Wanfeng Long, Hongyu Key Laboratory of Industrial Internet of Things and Networked Control Ministry of Education Chongqing University of Posts and Telecommunications Chongqing400065 China Chongqing University of Posts and Telecommunications Chongqing400065 China State Grid Chongqing Electric Power Company Chongqing400015 China Guangdong Provincial Key Lab of Robotics and Intelligent System Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen Shenzhen518055 China Chongqing Key Laboratory of Complex Systems and Bionic Control Chongqing University of Posts and Telecommunications Chongqing400065 China

The short-term hydrothermal scheduling (STHS) is a complex non-linear, non-convex and high-dimensional mathematical optimization problem. Due to the fact that the original chimp optimization algorithm (ChOA) is likely to fall into local optimum and has the disadvantage of low population diversity, an improved chimp optimization algorithm (IChOA) is proposed to solve the STHS problem. Firstly, Logistic-Tent chaotic mapping is employed to initialize the population and increase the population diversity. Then a new nonlinear convergence factor is introduced to make the optimization search process more applicable to STHS problems. Next, particle swarm algorithm (PSO) and gravitational search algorithm (GSA) are combined to enhance the shortcoming and balance the global search ability and local exploration ability of ChOA. Moreover, Cauchy mutation and opposition-based learning strategy are supplemented as perturbation interference when the optimal position is not updated to improve the ability to leap out of the local optimum. Finally, a graded optimization strategy is adopted for the constraint handing of dynamic reservoir balance and thermal power balance. Three standard hydrothermal power systems are utilized to verify the practicability and validity of the proposed method. Results of simulations reveal that IChOA has significant competitive advantages in addressing the STHS problem. © 2022, IAENG International Journal of Computer Science. All Rights Reserved.

关键词： Particle swarm optimization (PSO)

来源：评论

学校读者我要写书评

暂无评论

Distributed online optimal power flow for distribution system

引用

INTERNATIONAL JOURNAL OF ELECTRICAL power & ENERGY systemS 2020年 120卷 105970-000页

作者： Zhu, Xingxu Han, Xueshan Yang, Ming Xu, Yijing Wang, Shibo Shandong Univ Key Lab Power Syst Intelligent Dispatch & Control Minist Educ Jinan 250061 Shandong Peoples R China State Grid Shandong Elect Power Res Inst Jinan 250003 Shandong Peoples R China

This paper proposes a distributed online OPF algorithm for distribution systems with high integration of electronic-interfaced distributed energy resources (DERs). The algorithm can coordinate the update of DER setpoints on fast time scales only depending on local measurements and boundary information for each distribution area. Comparing with the existing distributed online algorithms that require some special setups (e.g., without considering the constraints on currents), the proposed algorithm can cope with various setups for the objective functions and constraints. The algorithm is based on solving the Taylor approximations of OPF problems by a distributed solution. In this solution, we design a strategy to formulate the second-order Taylor information in a distributed way by decomposing the sensitivities of the OPF targets among different areas;moreover, we design a method to simplify the constraints on DER outputs to accelerate the solution. The validity of the algorithm is verified by case studies, which show that it can continuously drive DER outputs towards the time-varying OPF targets composed of power losses and operation costs of DERs while satisfying the constraints on voltages and currents.

关键词： Distributed optimal power flow Distribution system Distributed energy resource Online algorithm

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：