International Journal of Electrical Power & Energy Systems最新文献

{"title":"Multistep photovoltaic power forecasting based on multi-timescale fluctuation aggregation attention mechanism and contrastive learning","authors":"Liang Yuan ,&nbsp;Xiangting Wang ,&nbsp;Yao Sun ,&nbsp;Xubin Liu ,&nbsp;Zhao Yang Dong","doi":"10.1016/j.ijepes.2024.110389","DOIUrl":"10.1016/j.ijepes.2024.110389","url":null,"abstract":"<div><div>The integration of photovoltaic (PV) power into electrical grids introduces significant uncertainty due to the inherent volatility and intermittency of solar energy, underscoring the need for precise short and medium-term PV power forecasting. Despite the superior performance of Transformer-based time series methods, their application to PV power prediction remains suboptimal. In response to this deficiency, this paper proposes a novel attention mechanism that aggregates fluctuations across multiple time scales. This mechanism enhances the segmentation and extraction of nonlinear correlations between PV power outputs and meteorological factors, assigning variable weights to patterns of change across different time scales. Furthermore, a novel approach for selecting similar days is also developed based on contrastive learning, which enables self-supervised identification of similarities among PV power samples and enhances the model’s attention to local dynamic variations. Comparative analysis with eight state-of-the-art benchmark methods shows that the proposed MFA-attention model achieves lower prediction errors and improved effectiveness.</div><div>© 2017 Elsevier Inc. All rights reserved.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110389"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy","authors":"Junjie Hou ,&nbsp;Qiangqiang Gao ,&nbsp;Yanfang Fan ,&nbsp;Guobing Song ,&nbsp;Xiaofang Wu ,&nbsp;Wentao Yang ,&nbsp;Runbin Cao ,&nbsp;Faxi Peng","doi":"10.1016/j.ijepes.2024.110396","DOIUrl":"10.1016/j.ijepes.2024.110396","url":null,"abstract":"<div><div>The flexible DC transmission project of renewable energy has become an inevitable development trend for large-scale renewable energy grid connection. Its two-terminal weak feed AC system is often composed of 100 % power electronic power equipment. The fault control strategy is used at both ends of the line to change the fault current characteristics, leading to a decrease in the performance of traditional differential protection. Based on analyzing the adaptability of current differential protection in the two-terminal weak feed AC system under traditional control strategy (TCS), this paper proposed an improved differential protection for two-terminal weak feed AC system considering negative sequence control coordination strategy. Firstly, the fault characteristics of the two terminal weak feed AC systems are analyzed. On this basis, the adaptability of differential protection under TCS is analyzed, and the quantization function that can quantify the operation performance of differential protection is given. Secondly, based on the problem of the traditional negative sequence control strategy, an improved control strategy is introduced and the operation performance of differential protection under the improved control strategy is studied. Finally, an improved differential protection scheme based on the change of current amplitude is proposed. Simulation results show that the proposed protection scheme can resist higher fault impedance(300 Ω) and noise interference(25 dB). In addition, the proposed differential protection scheme is suitable for the protection requirements of the two terminal weak feed AC systems in different scenarios and has higher sensitivity.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110396"},"PeriodicalIF":5.0,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced AC/DC optimal power flow via nested distributed optimization for AC/VSC-MTDC hybrid power systems","authors":"Haixiao Li ,&nbsp;Pedro P. Vergara ,&nbsp;Robert Dimitrovski ,&nbsp;Hongjin Du ,&nbsp;Aleksandra Lekić","doi":"10.1016/j.ijepes.2024.110365","DOIUrl":"10.1016/j.ijepes.2024.110365","url":null,"abstract":"<div><div>The deployment of voltage source converters (VSC) to facilitate flexible interconnections between the AC grid, renewable energy system (RES) and Multi-terminal DC (MTDC) grid is on the rise. However, significant challenges exist in exploiting coordinated operations for such AC/VSC-MTDC hybrid power systems. One of the most critical issues is how to achieve the optimal operation of such wide-area systems involving several power entities with as minimal communication burden as possible. To address this issue, an enhanced AC/DC optimal power flow (OPF) is specifically proposed. Firstly, a mixed-integer convex AC/DC OPF model is explicitly formulated to describe the optimal operation of such hybrid power systems. Subsequently, a nested distributed optimization method with double iteration loops is developed to offer optimal system-wide decision-making through a more “thorough” distributed communication architecture. In the outer iteration, the original AC/DC OPF problem is decomposed into several slave problems (SPs) associated with systems (including the AC grid and RESs) and one master problem (MP) associated with the integrated VSC-MTDC grid. Generalized Benders decomposition (GBD) serves to solve the master and slave problems iteratively. Techniques such as multi-cut generation and asynchronous updating are utilized to upgrade the GBD performance of computation efficiency and address communication delays. In the inner iteration, the master problem is continuously decomposed into multiple sub-MPs associated with individual VSCs. The alternating direction method of multipliers (ADMM) is employed to solve these sub-MPs iteratively. Proximal terms and heuristic approaches are embedded to enable parallel computation and handling of integer variables. Numerical experiment results finally validate the effectiveness of the proposed enhanced AC/DC OPF. The constructed AC/DC OPF model exhibits acceptable accuracy in terms of power flow calculation, and the developed nested distributed optimization method showcases decent convergence rate and solution optimality performances.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110365"},"PeriodicalIF":5.0,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mobile base station site as a virtual power plant for grid stability","authors":"Jussi Laimio ,&nbsp;Mika Keski-Heikkilä ,&nbsp;Matti Pärssinen ,&nbsp;Roope Lahti ,&nbsp;Olli Salmela ,&nbsp;Topi Volkov ,&nbsp;Jari Collin ,&nbsp;Petri Rannikko ,&nbsp;Henri Koskela ,&nbsp;Jukka Manner","doi":"10.1016/j.ijepes.2024.110390","DOIUrl":"10.1016/j.ijepes.2024.110390","url":null,"abstract":"<div><div>Energy grids and markets are in transition. Increased use of renewable energy sources (RES) introduces new stability challenges for power grids. Despite the substantial electrical consumption of mobile networks, they are yet to harness their inherent flexibility for aiding in the stability of the power grid. A noticeable research gap exists concerning measuring full activation time for fast frequency reserve (FFR) product while using batteries from mobile network base stations. Our objective is to demonstrate that mobile operators could use their existing infrastructure to participate in the reserve market of a contemporary power grid. Furthermore, it seeks to determine if the full activation time can meet the requirements of an FFR product. The system consists of a live mobile base station site with a mobile connection to the site, local controller, an existing battery, and a power system that, in combination, can function as part of a power grid balancing system. Our main finding indicates that the rectifier reaction time within an installed base station site infrastructure ranges from 5 to 8 s, and the time when the base station is entirely off from the grid varies from 7 to 10 s. This finding is significant since the activation time is too long for the base station power system controller to be used for FFR. The required full activation time for FFR is less than 1.3 s. In conclusion, power system vendors should investigate improvements for their equipment and software products to enable fast reserve market entry for their existing customers and stay competitive.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110390"},"PeriodicalIF":5.0,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel droop coefficient to realize rapid SOC balance for distributed energy storage systems","authors":"Yuanxi Liu,&nbsp;Ling Yang,&nbsp;Maohua Wei","doi":"10.1016/j.ijepes.2024.110398","DOIUrl":"10.1016/j.ijepes.2024.110398","url":null,"abstract":"<div><div>In the realm of isolated direct-current microgrids with varying distributed energy storage unit capacities, a new energy equalization strategy is proposed. This method involves an innovative approach that integrates an improved state-of-charge equalization control integrated with a sigmoid function to adaptively adjust the droop coefficient, aiming to accelerate the state-of-charge equalization rate. Furthermore, a virtual voltage drop equalization control is designed to dynamically adjust the output current of each distributed energy storage unit through a simple proportional–integral controller. This eliminates the influence of line impedance on accurate current distribution, improving overall accuracy. Additionally, a dynamic consistency algorithm is employed to gather average information about the distributed energy storage system, reducing communication line pressure as local nodes only exchange information with neighboring nodes. Integrating the aforementioned modules, the strategy proposed in this paper achieves rapid state-of-charge equalization, precise distribution of output current, and stable maintenance of the bus voltage. Finally, rigorous analysis of experimental results under various operating conditions verifies the feasibility and effectiveness of this control strategy by using the RT-LAB.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110398"},"PeriodicalIF":5.0,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and validation of a power modulation system for residential demand-side management","authors":"Aaron Goldin ,&nbsp;Elizabeth Buechler ,&nbsp;Ram Rajagopal ,&nbsp;Juan M. Rivas-Davila","doi":"10.1016/j.ijepes.2024.110374","DOIUrl":"10.1016/j.ijepes.2024.110374","url":null,"abstract":"<div><div>Residential loads have great potential to provide flexibility and other services to the grid, but many legacy or non-networked loads need additional hardware to enable such functionality. Currently available devices (e.g., smart thermostats or load control switches) that equip legacy loads with energy management features, provide narrow functionality to address specific use cases.</div><div>We propose the Smart Dim Fuse (SDF), a unified system with general purpose hardware, to enable legacy residential loads with versatile grid-interactive functionalities. By combining sensing, power electronics, and load modeling into a single architecture, the SDF offers comprehensive capabilities that would otherwise require a large number of disparate devices that are not inherently compatible. Based on a thoroughly tested prototype, we suggest that such a device can deliver this flexibility at a levelized cost of 0.018-0.052 $/kWh. The prototype power electronics operates at efficiencies between 96.4-98.5% at full load. The system can deliver fast load power modulation with a mean average percentage error below 1.8%.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110374"},"PeriodicalIF":5.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New frequency stability assessment based on contribution rates of wind power plants","authors":"SungHoon Lim ,&nbsp;KangWon Seo ,&nbsp;Jung-Wook Park ,&nbsp;Kwang Y. Lee","doi":"10.1016/j.ijepes.2024.110388","DOIUrl":"10.1016/j.ijepes.2024.110388","url":null,"abstract":"<div><div>In future power systems, various generation units are expected to contribute to frequency stability. Depending on their characteristics, these units will support the frequency stability in diverse ways. Traditionally, power systems have relied on synchronous generators (SGs), ensuring sufficient inertia and providing ancillary services for frequency stability. However, with the integration of multiple wind power plants (WPPs), which have substantially different characteristics, many countries are restructuring their ancillary service markets to accommodate WPPs.</div><div>This study proposes a novel frequency stability contribution rate index to analyze and compare the contribution of SGs and WPPs to frequency stability. To do so, this paper first analyzes the factors from SGs and WPPs, such as inertia, power reserves, resource conditions, and available frequency responses, and compares their roles in supporting frequency stability. The proposed index is then calculated using a multiple linear regression model that incorporates these factors. Therefore, this index provides a comprehensive evaluation of SGs and WPPs in terms of their contribution to frequency stability, offering valuable insights into their roles in supporting three key frequency stability indicators, the rate of change of frequency, frequency nadir, and settling frequency. The effectiveness of the proposed index is verified through case studies on the IEEE 39-bus system. In all cases, the coefficient of determination exceeds 95%, indicating a highly predictive regression model. Furthermore, as the penetration level of WPPs rises from 20% to 60%, the contribution weight of factors related to WPPs increases while that of SGs decreases.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110388"},"PeriodicalIF":5.0,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactive power optimization via deep transfer reinforcement learning for efficient adaptation to multiple scenarios","authors":"Congbo Bi ,&nbsp;Di Liu ,&nbsp;Lipeng Zhu ,&nbsp;Chao Lu ,&nbsp;Shiyang Li ,&nbsp;Yingqi Tang","doi":"10.1016/j.ijepes.2024.110376","DOIUrl":"10.1016/j.ijepes.2024.110376","url":null,"abstract":"<div><div>Fast reactive power optimization policy-making for various operating scenarios is an important part of power system dispatch. Existing reinforcement learning algorithms alleviate the computational complexity in optimization but suffer from the inefficiency of model retraining for different operating scenarios. To solve the above problems, this paper raises a data-efficient transfer reinforcement learning-based reactive power optimization framework. The proposed framework transfers knowledge through two phases: generic state representation in the original scenario and specific dynamic learning in multiple target scenarios. A Q-network structure that separately extracts state and action dynamics is designed to learn generalizable state representations and enable generic knowledge transfer. Supervised learning is applied in specific dynamic learning for extracting unique dynamics from offline data, which improves data efficiency and speeds up knowledge transfer. Finally, the proposed framework is tested on the IEEE 39-bus system and the realistic Guangdong provincial power grid, demonstrating its effectiveness and reliability.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110376"},"PeriodicalIF":5.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A decentralized optimization framework for multi-MGs in distribution network considering parallel architecture","authors":"Dengyin Jiang ,&nbsp;Xiaoqian Zhou ,&nbsp;Qian Ai ,&nbsp;Yuanjun Hou ,&nbsp;Yuan Zhao","doi":"10.1016/j.ijepes.2024.110252","DOIUrl":"10.1016/j.ijepes.2024.110252","url":null,"abstract":"<div><div>In view of centralized optimization facing the shortcomings of heavy communication burden, poor privacy, lack of autonomy or susceptibility to communication failures, a decentralized optimization framework is proposed to apply in parallel architecture particularly constituted by multi-microgrids (MMGs) in a distribution network based on accelerated analytical target cascading (ATC). Accelerated ATC algorithm can be applied to perform decentralized optimization in a sequential manner between distribution network agents and microgrid agents in a faster convergence speed compared with the traditional ATC algorithm. In order to ensure the stability of power flow and to incorporate unit commitment into the problem, a comprehensive economic dispatch model in the form of mixed-integer second-order cone programming (MISOCP) is developed and integrated into decentralized optimization framework. In our proposed decentralized optimization framework, each agent only needs to exchange a small amount of boundary information with its neighboring agents to find the feasible solutions without revealing their private operational information. The novelty of this work includes (1) the application and acceleration of the ATC algorithm in the proposed decentralized optimization framework; (2) the extensive investigation of the solution feasibility of the derived MISOCP problem for various penalty multipliers, scales and objective functions. Three types of microgrids (MGs) for residential, industry and business sectors are connected to the distribution network in parallel, respectively. Aiming at MMGs constructed by three MGs and six MGs in the distribution network, the proposed decentralized optimization framework is validated for the acceleration of ATC algorithm, varying penalty multipliers as well as different types of objective functions in terms of the feasibility of distributed solutions. Case studies based on the modified IEEE 33-bus distribution network are conducted to show the effectiveness of the decentralized optimization framework.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110252"},"PeriodicalIF":5.0,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A topology-guided high-quality solution learning framework for security-constraint unit commitment based on graph convolutional network","authors":"Liqian Gao,&nbsp;Lishen Wei,&nbsp;Shichang Cui,&nbsp;Jiakun Fang,&nbsp;Xiaomeng Ai,&nbsp;Wei Yao,&nbsp;Jinyu Wen","doi":"10.1016/j.ijepes.2024.110322","DOIUrl":"10.1016/j.ijepes.2024.110322","url":null,"abstract":"<div><div>Security-constrained unit commitment (SCUC) is of great importance for the economic and reliable operation of the power system. The computational hardness of SCUC remains a significant issue in the power system and electricity market operations, especially with the rapid expansion of the power system, leading to increased challenges of obtaining a high-quality solution in a fast way. In this sense, this paper proposes a topology-guided high-quality solution learning framework based on graph convolutional network (GCN) and neighborhood search (NS). Firstly, a GCN-based method is presented to learn the potential patterns between commitments and graph data associated with bus feature and power grid topology. Secondly, an adaptive threshold-based method is designed to fix binary variables to achieve model reduction. Thirdly, a customized prediction-based NS is developed to restore the feasibility of the predicted commitment. Case studies with different scales verify the effectiveness and efficiency of the proposed framework for SCUC. Compared with other methods, it demonstrates the superiority of learning based on power grid graph data. In the end, it can be concluded that the feasibility and high-quality of the solution can be guaranteed while reducing most of the computation time.</div></div>","PeriodicalId":50326,"journal":{"name":"International Journal of Electrical Power & Energy Systems","volume":"164 ","pages":"Article 110322"},"PeriodicalIF":5.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}