含可响应分布式电源的智慧能源配网多目标优化调度

分布式电源增加了配电网的灵活性,但同时也给配网调度带来一定挑战。文章针对含有可响应分布式电源的配网多目标优化调度进行研究。首先分析了居民智慧能源的特征以及居民用户、分布式电源、运行商三者的关系;然后考虑了分布式电源的不确定性,建立了风机和光伏的出力模型,从经济性、环保和配网可靠性角度建立了居民智慧能源配网多目标调度优化模型;针对配网负荷多样化的特点,提出了负荷因数模型,计及到多目标优化模型中;最后利用决策算法求解该模型,并在IEEE33节点系统中进行仿真,说明了所提模型和算法的有效性。     

An updated review of energy storage systems: Classification and applications in distributed generation power systems incorporating renewable energy resources

The demand of electric energy is increasing globally, and the fact remains that the major share of this energy is still being produced from the traditional generation technologies. However, the recent trends, for obvious reasons of environmental concerns, are indicating a paradigm shift towards distributed generation (DG) incorporating renewable energy resources (RERs). But there are associated challenges with high penetration of RERs as these resources are unpredictable and stochastic in nature, and as a result, it becomes difficult to provide immediate response to demand variations. This is where energy storage systems (ESSs) come to the rescue, and they not only can compensate the stochastic nature and sudden deficiencies of RERs but can also enhance the grid stability, reliability, and efficiency by providing services in power quality, bridging power, and energy management. This paper provides an extensive review of different ESSs, which have been in use and also the ones that are currently in developing stage, describing their working principles and giving a comparative analysis of important features and technical as well as economic characteristics. The wide range of storage technologies, with each ESS being different in terms of the scale of power, response time, energy/power density, discharge duration, and cost coupled with the complex characteristics matrices, makes it difficult to select a particular ESS for a specific application. The comparative analysis presented in this paper helps in this regard and provides a clear picture of the suitability of ESSs for different power system applications, categorized appropriately. The paper also brings out the associated challenges and suggests the future research directions.     

Energy management system for smart grid: An overview and key issues

Energy crisis and the global impetus to “go green” have encouraged the integration of renewable energy resources, plug-in electric vehicles, and energy storage systems to the grid. The presence of more than one energy source in the grid necessitates the need for an efficient energy management system to guide the flow of energy. Moreover, the variability and volatile nature of renewable energy sources, uncertainties associated with plug-in electric vehicles, the electricity price, and the time-varying load bring new challenges to the power engineers to achieve demand-supply balance for stable operation of the power system. The energy management system can effectively coordinate the energy sharing/trading among all available energy resources, and supply loads economically in all the conditions for the reliable, secure, and efficient operation of the power system. This paper reviews the framework, objectives, architecture, benefits, and challenges of the energy management system with a comprehensive analysis of different stakeholders and participants involved in it. The review paper gives a critical analysis of the distributed energy resources behavior and different programs such as demand response, demand-side management, and power quality management implemented in the energy management system. Different uncertainty quantification methods are also summarized. This review paper also presents a comparative and critical analysis of the main optimization techniques used to achieve different energy management system objectives while satisfying multiple constraints. Thus, the review offers numerous recommendations for research and development of the cutting-edge optimized energy management system applicable for homes, buildings, industries, electric vehicles, and the whole community.     

Future development of the electricity systems with distributed generation

Electrical power systems have been traditionally designed taking energy from high-voltage levels, and distributing it to lower voltage level networks. There are large generation units connected to transmission networks. But in the future there will be a large number of small generators connected to the distribution networks. Efficient integration of this distributed generation requires network innovations. A development of active distribution network management, from centralised to more distributed system management, is needed. Information, communication, and control infrastructures will be needed with increasing complexity of system management. Some innovative concepts such as microgrids and virtual utilities will be presented.     

Towards maximising the integration of renewable energy hybrid distributed generations for small signal stability enhancement: A review

Integrating renewable energy hybrid distributed generation (REHDG) into distribution network systems (DNSs) has become increasingly important because of various technical, economic, and environmental advantages accruing from it. However, the output power of REHDGs from photovoltaic (PV) and wind is highly variable because of its dependency on intermittent parameters such as solar irradiance, temperature, and wind speed. Such variability of generated power from large-scale REHDGs or load introduces small signal instabilities (oscillations). Meanwhile, different locations of integration and sizes of REHDGs in the DNS affect the system oscillation modes by either improving or depriving the small-signal stability (SSS) of the network. Consequently, a significant number of research has been conducted on the planning of optimal allocation of REHDGs in DNS. In this regard, this paper reviews the existing planning models, optimisation techniques, and resources' uncertainty modelling employed in REHDGs allocations in terms of their capability in obtaining optimal solutions and enhancing SSS of the system. Planning models with optimisation algorithms are evaluated for modelling renewable resource uncertainties and curtailing SSS variables. Research works on planning of optimal allocation of these generations attain minimum cost, but were unable to satisfy the SSS requirements of the system. The existing models for the planning and design of optimal timing, sizing, and placement of REHDGs will need to be improved to optimally allocate REHDGs and satisfy the SSS of the DNS after the integration.     

Investigation of the distributed generation penetration in a medium voltage power distribution network

This paper investigates the results of the distributed generation penetration in a weak medium voltage power distribution network. The connected distributed generation resources are in their entirety small hydroelectric plants. Their locations are predetermined. Specifically, the influence of distributed generation on the network branch currents and voltage profile as well as on the short‐circuit level at the medium voltage busbars of the infeeding substation are examined using a commercial‐grade software package. The arising problems are explored and alternative technical solutions to deal with them are proposed. Finally, an initial proposal for an optimum distributed generation penetration in the predetermined network positions is given. A real‐world study case, rather than a simplified academic network, is selected to be analysed in order to specify, as accurately as possible, the arising practical problems and to use this experience in the future in the development of a fast and reliable method for the determination of optimal distributed generation allocation in random network positions. Copyright © 2009 John Wiley & Sons, Ltd.     

计及逆变型分布式电源的有源配电网单相接地故障分析

风电、光伏等可再生能源以逆变型分布式电源(IIDG)形式并网后,使配电网成为有源配电网,其接地故障分布特点与传统配电网不同。文章通过分析恒功率控制型和低电压穿越控制型IIDG故障电流特性,建立其故障等值模型,然后,针对不接地系统建立计及IIDG的单相接地故障分析模型,分析并网变压器中性点不同接地方式和IIDG的接入位置下,故障点电流以及IIDG至故障点间线路零序电流特征分布,最后,通过PSCAD/EMTDC建立含IIDG接入的配电网故障仿真模型,验证了单相接地故障建模及分析方法的有效性。     

Energy supply performance and environmental load‐reduction effect of a cogeneration system for an apartment building using distributed heat storage technology

In order to make distributed generation systems for apartment buildings economically viable, it is essential to develop an efficient and low‐cost heat supply system. We are developing a new cogeneration system (Neighboring CoGeneration system: NCG system). The key concept of this system is to install a heat storage unit for the hot water supply, floor heating, and bath heating in each house, and to connect the heat storage units by a single‐loop hot water pipe. The system leads to time leveling of the total heat supply and reduced installation costs. Furthermore, it is expected that the cogeneration can operate according to electrical demand because of the large heat storage capacity of the system. In this study, a dynamic simulation model is developed to evaluate the performance and environmental load‐reduction effect of the NCG system for 50 households. The results show that the NCG system can supply sufficient heat for peak demand in winter and reduce annual CO₂ emissions by 23% on average. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 42(8): 745–757, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20376     

The research agenda on social acceptance of distributed generation in smart grids: Renewable as common pool resources

The rapid developing literature on ‘smart grids’ suggests that these will facilitate ‘distributed generation’ (DG) preferably from renewable sources. However, the current development of smart (micro)grids with substantial amount of DG (“DisGenMiGrids”) suffers from a focus on mere ‘technology’. Ongoing problems with deployment of renewable energy have shown that implementation is largely determined by broad social acceptance issues. This smart grid development is very important for further renewables deployment, but again there is a tendency to continue the neglect of social determinants.Most technical studies apply implicit and largely unfounded assumptions about the participation in and contribution of actors to DisGenMiGrid systems. This lack of understanding will have severe consequences: smart grids will not further renewables deployment when there are hardly actors that are willing to become part of them. This review is a first attempt to address the social construction of smart electricity grids. As institutional factors have proved to be the main determinants of acceptance, these will also be crucial for further renewables deployment in micro-grid communities. Elaboration of the institutional character of social acceptance and renewables’ innovation calls for an institutional theory approach involving Common Pool Resources management, because these socio-technical systems aim to optimise the exploitation of natural resources. Citizens/consumers and other end-users increasingly have the option to become more self-sufficient by becoming co-producers of electricity.They may optimise the contribution of DG when they cooperate and insert their renewable energy in a cooperative microgrid with mutual delivery. Moreover, the option to include ‘distributed storage’ capacity (electric vehicles) in these microgrids, enables an increasing share of renewables deployment. However, all these options should be institutionally opened. This requires much self-governance and flexible overall regulation that allows microgrids.The research agenda should focus on how such new systems become institutionally embedded, and how they are socially constructed.     

计及环境效益的虚拟电厂经济性优化调度

虚拟电厂（Virtual power plant, VPP）能有效减小新能源对电网的冲击,提高供电可靠性。本文在分析了VPP各分布式电源（Distributed generator, DG）发电成本的基础上,构建了计及环境效益的含风力发电、光伏发电、小水电和微型燃气轮机发电的VPP经济性优化调度模型,设计了基于小水电季节特性的VPP运行策略。以各时段内VPP实际出力跟踪计划出力、同时VPP发电成本和环境成本最小为目标,通过粒子群算法计算得到VPP各DG的出力。讨论了丰水期、平水期和枯水期VPP完成计划出力时微型燃气轮机出力系数,比较了丰水期、平水期和枯水期VPP发电成本和环境成本,并基于火力发电的环境成本计算了丰水期、平水期和枯水期VPP环境效益。实验结果验证了所建模型和运行策略的合理性,并表明VPP能有效平抑新能源出力偏差,降低DG发电总成本。     

Review on recent optimization strategies for hybrid renewable energy system with hydrogen technologies: State of the art,trends and future directions

The world is currently facing a power shortage due to the inadequacy of conventional energy sources and increased energy requirements in almost all sectors of human life. To mitigate this issue, the researchers have taken the considerable interest of researchers over the past decade in enhancing energy efficiency and viability. A hybrid renewable energy system (HRES) can efficiently produce clean energy to meet energy demand. Thus, it is extensively employed to improve power system quality, reliability, and economy, rather than solely relying on non-renewable energy sources. Nevertheless, RE sources' uncertain and intermittent nature, like wind speed and solar radiation, is associated with HRES. This problem can be solved with proper optimization by coupling HRES with energy conversion and storage devices, e.g., electrolyzer, fuel cell, and hydrogen tank, which can admirably balance power generation and energy demand. The literature is rich in employing optimization techniques on HRES with hydrogen technologies (HRES-H₂). However, a gap is found in the overall research progress of optimization approaches, considering HRES coupled with H₂ equipment. Therefore, the current study comprehensively reviews all the optimization approaches applied in this field worldwide. Further, a text mining-based software VOSviewer is used to investigate the scientific landscape of the literature body to figure out the current trends and future scope of HRES-H₂. It has been investigated that the researchers are focusing on: techno-economic optimization of HRES-H₂, developing sophisticated hydrogen infrastructure to reduce the overall cost of hydrogen fuel, introducing AI-based multi-objective optimization techniques to make the HRES-H₂ system more reliable and economically viable, and the impact of renewable and hydrogen technologies on the reduction of global warming. Lastly, an insightful of the current review highlighting the present shortcomings and opportunities of clean energy and hydrogen has been discussed, and suggestions are provided.     

Optimization of the structure of autonomous distributed hybrid power complexes and energy balance management in them

The paper offers a method for developing a universal system of automated design of an optimal structure of autonomous distributed hybrid energy complexes (ADHEC) and the means for regulation of the energy balance therein, i.e. control of the power flows circulating in the mentioned system. ADHEC will not only help unload the existing power system, but can also be used to produce “green” hydrogen. In general, the design of the optimal structure of ADHEC includes the following stages (subtasks): data research and creation of a statistical database of electric loads of consumers, the wind speed in the region under consideration, the hydroelectric potential of mountain and lowland rivers, and the solar energy, as well as the research and development of a database of converters of wind and water energy into electrical energy. The paper focused on the task of designing the optimal structure of the distributed hybrid generation system that will ensure the desired level of power generation at a minimal cost and with necessary functional reliability.     

Towards a future with large penetration of distributed generation: Is the current regulation of electricity distribution ready? Regulatory recommendations under a European perspective

The European Energy Policy promotes renewable energy sources and energy efficiency as means to mitigate environmental impact, increase security of supply and ensure economic competitiveness. As a result, the penetration levels of distributed generation (DG) in electricity networks are bound to increase. Distribution networks and distribution system operators (DSOs) will be especially affected by growing levels of DG. This paper reviews the current regulation of distribution in the European Union Member States, focusing on those aspects that might hinder the future integration of DG. Several regulatory issues that may hinder a successful integration of DG have been identified. Recommendations to improve the current situation are proposed. Regarding economic signals sent to DG, connection charges and cost-reflective use-of-system charges together with incentives to provide ancillary services are the key aspects. Concerning DSOs regulation, unbundling from generation and supply according to the European Electricity Directive, incentives for optimal planning and network operation considering DG, including energy losses and quality of service, and innovation schemes to migrate to active networks are the most relevant topics.     

Modelling and optimization of the smart hybrid renewable energy for communities (SHREC)

The future energy system in community level should be more ‘smart’ to secure reliability, enhance market service, minimize environmental impact, reduce costs and improve the use of renewable energy source (RES). Therefore, this paper proposes an energy integration system – smart hybrid renewable energy for communities (SHREC). It considers both thermal (heating and cooling) and electricity market in a large community level and highlight the interactions between them through utilizing RES, combined heat and power (CHP) and energy storages. A planning model based on CHP modelling is developed for the SHREC system. A linear programming (LP) algorithm is developed to optimize the SHREC system in a weekly period and the results are compared with an existing energy optimization software. We also demonstrate the model in a sample SHREC system during three typical weeks with cold, warm and mid-season weather in the year 2011. The results indicate that the developed modelling and optimization method is more efficient and flexible for the smart hybrid renewable energy systems.     

Internalisation of external cost in the power generation sector: Analysis with Global Multi-regional MARKAL model

The Global MARKAL-Model (GMM), a multi-regional “bottom-up” partial equilibrium model of the global energy system with endogenous technological learning, is used to address impacts of internalisation of external costs from power production. This modelling approach imposes additional charges on electricity generation, which reflect the costs of environmental and health damages from local pollutants (SO₂, NO_x) and climate change, wastes, occupational health, risk of accidents, noise and other burdens. Technologies allowing abatement of pollutants emitted from power plants are rapidly introduced into the energy system, for example, desulphurisation, NO_x removal, and CO₂ scrubbers. The modelling results indicate substantial changes in the electricity production system in favour of natural gas combined cycle, nuclear power and renewables induced by internalisation of external costs and also efficiency loss due to the use of scrubbers. Structural changes and fuel switching in the electricity sector result in significant reduction of emissions of both local pollution and CO₂ over the modelled time period. Strong decarbonisation impact of internalising local externalities suggests that ancillary benefits can be expected from policies directly addressing other issues then CO₂ mitigation. Finally, the detailed analysis of the total generation cost of different technologies points out that inclusion of external cost in the price of electricity increases competitiveness of non-fossil generation sources and fossil power plants with emission control.     

Regulatory framework and business models for charging plug-in electric vehicles: Infrastructure,agents, and commercial relationships

Electric vehicles (EVs) present efficiency and environmental advantages over conventional transportation. It is expected that in the next decade this technology will progressively penetrate the market. The integration of plug-in electric vehicles in electric power systems poses new challenges in terms of regulation and business models. This paper proposes a conceptual regulatory framework for charging EVs. Two new electricity market agents, the EV charging manager and the EV aggregator, in charge of developing charging infrastructure and providing charging services are introduced. According to that, several charging modes such as EV home charging, public charging on streets, and dedicated charging stations are formulated. Involved market agents and their commercial relationships are analysed in detail. The paper elaborates the opportunities to formulate more sophisticated business models for vehicle-to-grid applications under which the storage capability of EV batteries is used for providing peak power or frequency regulation to support the power system operation. Finally penetration phase dependent policy and regulatory recommendations are given concerning time-of-use pricing, smart meter deployment, stable and simple regulation for reselling energy on private property, roll-out of public charging infrastructure as well as reviewing of grid codes and operational system procedures for interactions between network operators and vehicle aggregators.