Coordinated planning for flexible interconnection and energy storage system in low-voltage distribution networks to improve the accommodation capacity of photovoltaic

The increasing proportion of distributed photovoltaics(DPVs)and electric vehicle charging stations in low-voltage distribution networks(LVDNs)has resulted in challenges such as distribution transformer overloads and voltage violations.To address these problems,we propose a coordinated planning method for flexible interconnections and energy storage systems(ESSs)to improve the accommodation capacity of DPVs.First,the power-transfer characteristics of flexible interconnection and ESSs are analyzed.The equipment costs of the voltage source converters(VSCs)and ESSs are also analyzed comprehensively,considering the differences in installation and maintenance costs for different installation locations.Second,a bilevel programming model is established to minimize the annual comprehensive cost and yearly total PV curtailment capacity.Within this framework,the upper-level model optimizes the installation locations and capacities of the VSCs and ESSs,whereas the lower-level model optimizes the operating power of the VSCs and ESSs.The proposed model is solved using a non-dominated sorting genetic algorithm with an elite strategy(NSGA-II).The effectiveness of the proposed planning method is validated through an actual LVDN scenario,which demonstrates its advantages in enhancing PV accommodation capacity.In addition,the economic benefits of various planning schemes with different flexible interconnection topologies and different PV grid-connected forms are quantitatively analyzed,demonstrating the adaptability of the proposed coordinated planning method.

Insights into Nano-and Micro-Structured Scaffolds for Advanced Electrochemical Energy Storage

Adopting a nano-and micro-structuring approach to fully unleashing the genuine potential of electrode active material benefits in-depth understandings and research progress toward higher energy density electrochemical energy stor-age devices at all technology readiness levels.Due to various challenging issues,especially limited stability,nano-and micro-structured(NMS)electrodes undergo fast electrochemical performance degradation.The emerging NMS scaffold design is a pivotal aspect of many electrodes as it endows them with both robustness and electrochemical performance enhancement,even though it only occupies comple-mentary and facilitating components for the main mechanism.However,extensive efforts are urgently needed toward optimizing the stereoscopic geometrical design of NMS scaffolds to minimize the volume ratio and maximize their functionality to fulfill the ever-increasing dependency and desire for energy power source supplies.This review will aim at highlighting these NMS scaffold design strategies,summariz-ing their corresponding strengths and challenges,and thereby outlining the potential solutions to resolve these challenges,design principles,and key perspectives for future research in this field.Therefore,this review will be one of the earliest reviews from this viewpoint.

Autonomous Multi-Factor Energy Flows Controller (AmEFC): Enhancing Renewable Energy Management with Intelligent Control Systems Integration

The transition to sustainable energy systems is one of the defining challenges of our time, necessitating innovations in how we generate, distribute, and manage electrical power. Micro-grids, as localized energy hubs, have emerged as a promising solution to integrate renewable energy sources, ensure energy security, and improve system resilience. The Autonomous multi-factor Energy Flow Controller (AmEFC) introduced in this paper addresses this need by offering a scalable, adaptable, and resilient framework for energy management within an on-grid micro-grid context. The urgency for such a system is predicated on the increasing volatility and unpredictability in energy landscapes, including fluctuating renewable outputs and changing load demands. To tackle these challenges, the AmEFC prototype incorporates a novel hierarchical control structure that leverages Renewable Energy Sources (RES), such as photovoltaic systems, wind turbines, and hydro pumps, alongside a sophisticated Battery Management System (BMS). Its prime objective is to maintain an uninterrupted power supply to critical loads, efficiently balance energy surplus through hydraulic storage, and ensure robust interaction with the main grid. A comprehensive Simulink model is developed to validate the functionality of the AmEFC, simulating real-world conditions and dynamic interactions among the components. The model assesses the system’s reliability in consistently powering critical loads and its efficacy in managing surplus energy. The inclusion of advanced predictive algorithms enables the AmEFC to anticipate energy production and consumption trends, integrating weather forecasting and inter-controller communication to optimize energy flow within and across micro-grids. This study’s significance lies in its potential to facilitate the seamless incorporation of RES into existing power systems, thus propelling the energy sector towards a more sustainable, autonomous, and resilient future. The results underscore the potential of such a system to revolutionize energy management practices and highlight the importance of smart controller systems in the era of smart grids.

Impact of interconnections and renewable energy integration on the Philippine-Sabah Power Grid systems

This study presents a comprehensive impact analysis of the rotor angle stability of a proposed international connection between the Philippines and Sabah,Malaysia,as part of the Association of Southeast Asian Nations(ASEAN)Power Grid.This study focuses on modeling and evaluating the dynamic performance of the interconnected system,considering the high penetration of renewable sources.Power flow,small signal stability,and transient stability analyses were conducted to assess the ability of the proposed linked power system models to withstand small and large disturbances,utilizing the Power Systems Analysis Toolbox(PSAT)software in MATLAB.All components used in the model are documented in the PSAT library.Currently,there is a lack of publicly available studies regarding the implementation of this specific system.Additionally,the study investigates the behavior of a system with a high penetration of renewable energy sources.Based on the findings,this study concludes that a system is generally stable when interconnection is realized,given its appropriate location and dynamic component parameters.Furthermore,the critical eigenvalues of the system also exhibited improvement as the renewable energy sources were augmented.

Prospects for key technologies of new-type urban integrated energy system

In recent years,primary energy consumption in China’s urban areas has increased rapidly,facing the problems of extensive use of energy,high energy consumption and insufficient intensified use of energy resources.Improving multienergy supply,increasing the proportion of clean energy and integrated energy efficiency are the main goals of urban development.The integrated energy system with multi-functional synergy and open trading will become one of the new directions for the development of new urban energy systems.This paper summarizes the main problems faced by the current towns and the characteristics of the new urban energy system,analyzes the development of new urban energy system from three aspects including energy interconnection hub infrastructure construction,energy management platform construction and energy value sharing,and forecasts the future development direction of new urban energy systems.

Application research on large-scale battery energy storage system under Global Energy Interconnection framework

In the context of constructing Global Energy Interconnection(GEI), energy storage technology, as one of the important basic supporting technologies in power system, will play an important role in the energy configuration and optimization. Based on the most promising battery energy storage technology, this paper introduces the current status of the grid technology, the application of large-scale energy storage technology and the supporting role of battery energy storage for GEI. Based on several key technologies of large-scale battery energy storage system, preliminary analysis of the standard system construction of energy storage system is made, and the future prospect is put forward.

Development of the interconnected power grid in Europe and suggestions for the energy internet in China

The European power grid is one of the largest regional interconnected power grids in the world.It realizes a multinational grid operation,which is rare.The total installed capacity of the European power grid is the largest throughout the world.In addition,the integration and utilization of renewable energy in this grid is a great benchmark for other countries and can help promote energy transformation and achieve a high proportion of renewable energy consumption.Based on the analysis of the existing status of the European interconnected power grid and the development history of this power grid,this paper summarizes four key development stages of the European power grid.In addition,the characteristics of each stage and the development prospect of the European power grid are analyzed.On this basis,this paper gives suggestions for the development and construction of China’s energy internet;this can provide valuable reference for further studies on China’s energy internet.

Synergies of carbon neutrality, air pollution control, and health improvement - a case study of China Energy Interconnection scenario

Climate change and air pollution are primarily caused by the combustion and utilization of fossil fuels.Both climate change and air pollution cause health problems.Based on the development of China,it is extremely important to explore the synergies of the energy transition,CO_(2) reduction,air pollution control,and health improvement under the target of carbon peaking before 2030 and carbon neutrality before 2060.This study introduces the policy evolution and research progress related to energy,climate change,and the environment in China and proposes a complete energy-climate-air-health mechanism framework.Based on the MESSAGE-GLOBIOM integrated assessment model,emission inventory and chemical transport model,and exposure-response function,a comprehensive assessment method of energy-climate-air-health synergies was established and applied to quantify the impacts of Chinese Energy Interconnection Carbon Neutrality(CEICN)scenario.The results demonstrate that,by 2060,the SO_(2),NO_(x) and PM_(2.5) emissions are estimated to be reduced by 91%,85%,and 90%respectively compared to the business-as-usual(BAU)scenario.The direct health impacts brought by achieving the goal of carbon neutrality will drive the proactive implementation of more emission reduction measures and bring greater benefits to human health.

Power Optimization Cooperative Control Strategy for Flexible Fast Interconnection Device with Energy Storage

With the wide application of renewable energy power generation technology,the distribution network presents the characteristics of multi-source and complex structure.There are potential risks in the stability of power system,and the problem of power quality is becoming more and more serious.This paper studies and proposes a power optimization cooperative control strategy for flexible fast interconnection device with energy storage,which combines the flexible interconnection technology with the energy storage device.The primary technology is to regulate the active and reactive power of the converter.By comparing the actual power value of the converter with the reference value,the proportional integral(PI)controller is used for correction,and the current components of d and q axes are obtained and input to the converter as the reference value of the current inner loop.The control strategy in this paper can realize power mutual aid between feeders,and at the same time,the energy storage device can provide or absorb a certain amount of power for feeders,so that the power grid can realize stable operation in a certain range.

Research on key technologies of deduction of multinational power trading in the context of Global Energy Interconnection

When transnationalized electricity trade is conducted in the context of Global Energy Interconnection(GEI),the transaction settlement usually has a long cycle and high cost and is influenced by the volatility of the exchange rate.It is thus necessary to overcome the problems associated with the transaction settlement,change in the trading model data,and trading strategy in the transnational transaction deduction.To overcome the problem of trade settlement,this paper proposes the use of a digital currency(energy currency)for the cross-border electricity trading settlement based on the special drawing rights of the International Monetary Fund,which is controlled by the Global Energy Interconnection Development and Cooperation Organization(GEIDCO),to enable the proposed currency to become a stable digital currency.The traders can use the energy coins as a unit of currency for quotes,combined with the data pertaining to the changes in the energy information obtained from the GEI framework and data regarding the optimally extrapolated reference trading indicators.To realize the implementation of the multi-trader concurrent transaction deduction using a microservice architecture,this paper proposes a method of computing the microservice and synchronous interaction among the traders,based on the database table data,because the large amount of computation is required to be accomplished asynchronously with a single process.The key technology behind these cross-national electricity trading simulations can not only enable the GEI transnational traders to performed daily real-time trading,but it also demonstrates the advantages of the rapid settlement of the energy currency and the realization of a stable payment in the global energy interconnection cross-border electricity trading.

New Robust Energy Management Model for Interconnected Power Networks Using Petri Nets Approach

The problematic of energy management, particularly in terms of resources control and efficiency, has become in the space of a few years an eminently strategic subject. Its implementation is both complex and exciting as the prospects are promising, especially in relation with smart grids technologies. The deregulation of the electricity market, the high cost of storage, and the new laws on energy transition incite some significant users (collectivities, cities, regions, etc.) to form themselves into local producers in order to gain autonomy and reduce their energy bills. Thus, they may have their own sources (classic and/or renewable energy sources) to satisfy their needs and sell their excess production instead of storing it. In this idea, the territorial interconnection principle offers several advantages (energy efficiency, environmental protection, better economic balance). The main challenge of such systems is to ensure good energy management. Therefore, power distribution strategy must be implemented by matching the supply and the demand. Such systems have to be financially viable and environmentally sustainable. This allows among others to reduce the electricity bill and limit the systematic use of the national power network, typically using non-renewable sources, and thereby support sustainable development. This paper presents an original model for aid-decision in terms of grid configurations and control powers exchanged between interconnected territories. The model is based on Petri nets. Therefore, an iterative algorithm for power flow management is based on instantaneous gap between the production capability (photovoltaic, wind) and the demand of each user. So, in order to validate our model, we selected three French regions: the PACA region, the Champagne-Ardenne region and the Lorraine region. Due to their policy, their geographical and climatic features, we opted for two renewable sources: “wind” and “photovoltaic”. The numerical simulations are performed using the instantaneous productions of each region and their energy demand for a typical summer day. A detailed economic analysis is performed for two scenarios (with or without interconnections). The results show that the use of renewable energy in an interconnection context (i.e. pooling), offers serious economic and technical advantages.

含高比例新能源的异步互联送端系统直流FLC的阶跃死区控制策略及优化

针对含高比例新能源的异步送端系统直流频率限制控制器(FLC)死区控制及参数优化问题,提出了一种直流FLC阶跃死区控制策略。基于考虑含高比例新能源的多机系统频率响应模型,分析了直流FLC死区参数以及高比例新能源装机容量对送端系统频率响应的影响。加入阶跃决策系统,构建改进型直流FLC阶跃死区控制策略。搭建兼顾直流FLC动作特性以及对送端系统频率偏差抑制效果的改进型直流FLC阶跃死区控制策略参数优化模型。使用群智能算法求解出改进型直流FLC阶跃死区控制器最优参数。仿真结果表明优化后的直流FLC死区控制方法可以显著改善送端系统的频率稳定支撑能力。

分布式储能在成都科幻馆的应用

通过电化学储能在2023年第81届世界科幻大会主场馆——成都科幻馆项目的示范应用,重点从应用场景、并网接入电压、接入系统方案、运行策略等方面分析用户侧分布式储能在民用建筑的应用要点。

考虑电压-无功调节的台区互联装置规划方法

伴随分布式能源广泛接入低压配电网,其对配电网运行灵活性和消纳能力的要求不断提高。利用低压柔性互联装置将独立运行的低压配电台区分区互联,避免传统电压调节和无功补偿装置频繁动作。考虑到柔性互联装置造价昂贵,协同传统电压-无功调节装置,文中提出低压柔性互联装置的选址定容规划方法。首先,分析低压柔性互联装置拓扑和运行方式,建立其潮流模型。其次,建立低压柔性互联装置优化配置的双层规划模型,上层规划以年综合费用最小为目标,下层规划考虑电压-无功协调控制时间序列模型,以运行成本和电压偏差最小为目标,基于粒子群优化算法和混合整数二阶锥规划算法交替求解,得出配电系统最优柔性互联方案和最优运行方式。最后,在IEEE 33节点系统上进行实例分析,验证该双层规划算法的有效性。结果表明,所提方法能有效减少柔性互联装置的过度布置,同时减少由分布式能源频繁波动造成的运行成本。将模型凸化并线性化的方法明显提高了求解效率。

虚拟母线式多端无线能量互联系统混合式多线圈结构设计与效率优化

在面向区域型电能互联应用的虚拟交流母线式多端无线能量互联系统中,双极型线圈较低的耦合系数会导致母线侧线圈损耗过高,系统效率偏低。为此,该文提出一种混合式线圈结构,即利用平面方形线圈替代原来单一式结构中的部分双极型线圈,在保证多线圈交叉解耦的前提下提高耦合系数。在该结构的基础上,对系统参数展开优化设计。基于线圈拆分与等效的思想,提出一种统一化线圈建模方法,以此获取最大效率下线圈匝数、补偿电感和母线电流幅值的最优取值。最后,搭建四端口原理样机验证所提线圈结构和参数优化设计的有效性,优化后的系统其在不同运行模式下的效率均提升8%以上。

计及能量互济的多区域综合能源系统多目标双层优化

多区域综合能源系统(integrated energy system,IES)的能量供需关系复杂,增加了系统规划及运行调度的难度。为此,提出了计及区域能量互济的多目标双层优化策略。其中,规划层选取年化总成本、㶲效率及年碳排放量作为优化子目标,并对子目标赋予权重因子,建立多目标优化模型;调度层以日运行成本最低为目标函数,并计及区域能量互济的作用。分别采用线性权重递减的粒子群优化算法和整数线性规划方法求解规划及调度问题,实现了二者的协同优化。算例分析表明:双层优化策略将IES的运行特性纳入规划过程,提高了规划方案的可行性;应合理配置多目标优化的权重因子,以实现多目标的合理折中;区域能量互济能够优化IES的运行方式,提高综合效益。

计及多时段尺度与地域分层的多能互补系统经济调度

在考虑电热能源互联基础上,提出了计及多时段尺度与地域分层的电热多能互补系统经济调度策略,该策略从单时段和多时段角度出发,综合考虑局域级和区域级的能量平衡关系,以实现电热多能互补系统经济调度为目标。首先,在采集局域级各类能源资源数据与信息的基础上建立母线式电、热能平衡模型;然后,提出区域级能量平衡公共母线式模型,并采用小容量机组等效思想来等效聚合同类型机组;其次,建立典型局域级电热互联能源系统模型;最后,对电热多能互补系统经济调度求解,并输出经济调度结果信息。对电热多能互补系统的经济调度的有效性与合理性通过仿真算例已经得到验证,为区域级电热多能互补系统多能互补利用、资源协调配合、经济高效运行及分析提供参考与理论指导。

考虑互联协同的分布式能源站低碳多目标选址规划研究

“双碳”目标和能源转型的大背景下,区域综合能源系统内部耦合关系不断丰富,对于碳排放的管理不断严格,考虑互联协同的分布式能源站低碳规划问题亟待解决。为此,首先讨论了互联协同分布式能源站空间性能参数矩阵;然后计及负荷-能源站的管线建设以及环境成本、能源站-能源站的互联管线长度、各个分布式能源站规划容量等关键因素,提出了一种考虑互联协同的分布式能源站低碳多目标选址规划模型;最后,讨论了负荷不确定性对分布式能源站选址规划的影响,并且基于基准负荷确定性场景,在某城市实际算例中验证并讨论了考虑低碳需求前后各个分布式能源站的选址结果对比。

Electricity-Heat-Based Integrated Demand Response Considering Double Auction Energy Market with Multi-Energy Storage for Interconnected Areas

With development of integrated energy systems and energy markets,transactive energy has received increasing attention from society and academia,and realization of energy distribution and integrated demand response through market transactions has become a current research hotspot.Research on optimized operation of a distributed energy station as a regional energy supply center is of great significance for improving flexibility and reliability of the system.Based on retail-side energy trading market,this study first establishes a framework of combined electric and heating energy markets and analyses a double auction market mechanism model of interconnected distributed energy stations.This study establishes a mechanism model of energy market participants,and establishes the electric heating combined market-clearing model to maximize global surplus considering multi-energy storage.Finally,in the case study,a typical user energy consumption scenario in winter is selected,showing market-clearing results and demand response effects on a typical day.Impact of transmission line constraints,energy supply equipment capacity,and other factors on clearing results and global surplus are compared and analyzed,verifying the effects of the proposed method on improving global surplus,enhancing interests of market participants and realizing coordination and optimal allocation of both supply and demand resources through energy complementarity between regions.

EID-based Load Frequency Control for Interconnected Hybrid Power System Integrated with RESs

By considering the influence of renewable energy sources(RESs)integration on multi-area interconnected hybrid power systems,this paper proposes an equivalent input disturbance(EID)-based load frequency control(LFC)strategy,which can effectively overcome the factors of random disturbance,model uncertainties and communication delay.First,an equivalent mathematical LFC model of an interconnected system is constructed.Then,the proposed robust controllers,based on the idea of EID,are designed to suppress the randomness and volatility of the renewable energy grid connection and coordinate the frequency fluctuation of the interconnected power system.Finally,the validity and superiority of the established topology structure and the superiority of the proposed strategy are demonstrated by dynamic time domain response experiments under the condition of high penetration of renewable energy.