Application of Power Electronics Converters in Renewable Energy

Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.

Research on the Impact of New and Renewable Energy Replacing Fossil Energy Resource under Constraint of Carbon Emissions

For studying new and renewable energy as a substitute for fossil energy in primary energy consumption and its impact on carbon emissions to cope with economic uncertainties, a multi-sector DSGE model was employed to simulate the dynamic impact on carbon emissions and macroeconomic development. The structural adjustment of energy consumption and the carbon emissions mitigation policy were considered in the model. The simulation results showed that using new and renewable energy instead of fossil energy is an optimal choice for the firms to comply with the regulations of carbon emission mitigation policy. Structural adjustment of energy consumption is the best route to achieve the dual goal of economic development and carbon emission reduction. Unexpected sharp fall in free carbon quota has a negative impact on the economy.

Development Plan of New and Renewable Energy Industry in China for Year 2000-2015

This paper presents the guidelines and basic ideas for working out the development plan of new and renewable energy based upon China’s conditions, the foundation of industrialization development, targets of development for year 2000-2015 and the main tasks of industrialization system construction.

Special Issue on New Concepts and Advances in Photocatalytic Materials for Sustainable Energy

The use of solar energy to drive the chemical and energy processes,and the chemical storage of solar energy are the key elements to move to a low-carbon economy,sustainable society and to foster energy transition.For this reason,there is a fast-growing scientific interest on this subject,which is part of the general effort for a solar-driven chemistry and energy,the chemistry of the future.To realize this

New and Renewable Energy Development in China's Rural and Remote Area

This paper analyses the present situation of new and renewable energy development in China’s rural and remote areas and gives the development objectives and tasks which could be fulfilled in the future. At last, it is summed up that exploiting new and renewable energy is the national key strategy for rural economic development.

The Program for the Development of Chinese New and Renewable Energy (1996-2010) Worked Out

The State Science and Technology Commission, State Economic and Trade Commission, and State Planning Commission of China have jointly worked out the Program for the Development of Chinese New and Renewable Energy recently.

An Overview on Advanced Grid-connected Inverters Used for Decentralized Renewable Energy Resources

并网逆变器是分散式可再生能源接入配电网的重要接口,随着分布式可再生能源渗透率的不断提高,并网逆变器在传统配电网中的地位越发突出。为了高效完成可再生能源分散式并网,并有效降低并网逆变器对电网的冲击,一些在装置上、结构上和功能上更加先进的并网逆变器成为了迫切的需求。针对现有的一些先进并网逆变器进行比较、分析和研究,从装置级、功能级和控制级的角度对现有先进并网逆变器进行综述。给出一些在结构上能更加灵活地将可再生能源分散接入配电网的硬件电路。研究一些适用于可再生能源分散接入的,使并网逆变器能虚拟同步发电机完成自治运行、电能质量治理、系统阻抗检测、网络阻抗控制等辅助控制功能。同时还对并网逆变器的并网同步算法和电流跟踪控制策略进行了探讨。最后,提出一个适合于可再生能源分散并网的先进并网逆变器框架。

Application of Renewable Energies in the Construction of New Rural Residences

Based on the significance of renewable resources in relieving energy crisis,application of renewable resources for reducing energy consumption of rural housings and carbon emission of traditional energies are believed as an inevitable choice for the construction of a conservation-minded society.Taking easily-acquired and low-cost solar energy,biomass energy and rainwater for example,strategies of applying renewable resources in rural housings are discussed.And the research focuses on the application of solar energy PV Power System and solar energy photo-thermal power system in rural residence,significance of power system such as methane and waste reusing for the integrated utilization of biomass energy and residence,and also recycling and cooling effects of intermediate water.

Assessment on Fault Diagnosis and State Evaluation of New Power Grid:AReview

1 Introduction The proposal of the concept of“New Power System”aims to illustrate the transform direction of the traditional power system,acting as the development core of the future new power grid.To achieve this,the proposed strategic targets of“carbon neutralization and carbon peaking”must be implemented and insisted[1].The core feature of the new power system is that renewable energy plays a leading role and becomes the main source of energy supply,meanwhile,the goal of green energy utilization has also been put forward on the agenda.Green energy utilization includes two aspects,one is the exploitation and promotion of various green energy technologies,and the other is the digitalization of energy management.Under this trend,stochastic and fluctuating energy sources such as wind power and photovoltaic power replace deterministic controllable power sources such as thermal power,bringing challenges to power grid regulation and dispatching,as well as flexible operation.The large-scale integration of renewable energy and increasingly high proportion of power electronic equipment tend to bring about fundamental changes in the operation characteristics,safety control,and production mode of the power system.

Path selection and mechanism innovation of improving railway energy efficiency–from foreign experience and Chinese practice

Purpose–Under the dual pressure of resources and environment,many countries have focused on the role of railways in promoting low-carbon development of integrated transportation and of even the whole society.This paper aims to provide a comprehensive study on methods to improve railway energy efficiency in other national railways and achievements made by China’s railways in the past practice,and then to propose ways in which in the future China’s railways could rationally select the path of improving energy efficiency regarding the needs of the nation’s ever-shifting development and carry out the re-engineering for mechanism innovation in energy conservation and emission reduction process.Design/methodology/approach–This paper first studies other national railways that have tried to promote the improvement of railway energy efficiency by the ways of technology,management and structural reconstruction to reduce energy consumption and carbon emissions.Among them,the effect of structural energy conservation and emission reduction has become more prominent.It has become the main energy conservation and emission reduction measure adopted by foreign railway sectors.The practice of energy conservation and emission reduction of railways in various countries has tended to shift from a technical level to a structural one.Findings–Key aspects in improving energy efficiency include re-optimization of energy structure,reinnovation of energy-saving technologies and optimization of transportation organization.Path selection includes continuing to promote electrified railway construction,increasing the use of new and renewable energy sources,and promoting the reform of railway transportation organizations.Originality/value–This paper provides further challenges and research directions in the proposed area and has referential value for the methodologies,approaches for practice in a Chinese context.To achieve the expected goals,relevant supporting policies and measures need to be formulated,including actively guiding integrated transportation toward railway-oriented development,promoting innovation in energy-saving and emission reduction mechanisms and strengthening policy incentives,focusing on improving the energy efficiency of railways through market behavior.At the same time,it is necessary to pay attention to new phenomena in the railway industry for track and analysis.

适应新型电力系统的电力互替品市场——(一)理念与构想

新型电力系统重塑了能源生产消费结构,电力市场机制也需随之改变。首先,分析指出提升系统调节能力是新型电力系统下市场机制设计的首要目标;围绕该目标给出了市场机制应具备的特点,包括利于激发调节动力、释放调节能力、接纳各种新型调节资源等。其次,对世界各国现货市场普遍采用的分时交易机制进行了分析,指出其与新型电力系统存在诸多不适应之处,包括市场主体调节贡献无法被量化表征,市场主体连续运行特性与分时交易机制相矛盾、调节能力难以完全释放,以及难以满足海量柔性资源直接参与电力市场的需求等。为此,文中舍弃分时交易的方式,转而提出整体交易机制与电力互替品概念,介绍了形成与交易电力互替品的主要思路,并以电力互替品为核心构想了新型市场机制。该机制可通过调节责任划分量化各主体调节贡献,激发市场主体的调节动力;同时,也能促进市场主体主动优化自身运行方式,释放调节能力;具有易于扩展的优势,可轻松接纳新型电力系统下层出不穷的各类新型主体。

电力电量平衡视角下新型电力系统极端场景研究及应对综述

全球气候变化加剧背景下极端天气事件频发,受能源转型政策、地缘政治影响一次能源供应与负荷水平均呈现强不确定性。中国正处于可再生能源占比不断提升的新型电力系统建设阶段,极端场景下电力电量平衡问题凸显并呈现出加剧趋势。基于此,从极端场景基本内涵、模拟与生成技术、在电力系统中的应用以及应对措施等角度入手,总结电力电量平衡视角下新型电力系统中的极端场景研究。首先,归纳了极端场景的定义与特性,指出了极端场景与极端事件、最恶劣场景等概念之间联系,归纳了极端场景集的构建方法;随后,针对极端场景小样本特性,梳理了极端场景的直接与间接生成方法;探讨了极端场景在电力系统中的应用方法与具体应用领域;最后,结合现有研究与实际工程案例从4个层面提出了极端场景的应对策略,并指出了极端场景的后续研究方向,为后续建设灵活可靠、供需平衡的电力系统提供了思路。

考虑实时备用率的中长时间尺度新能源发电备用的方法

在新型电力系统中,考虑到中长期时间尺度下新能源出力具有较强规律性,提出了中长时间尺度新能源纳入备用的实时备用率的确定方法。根据实时备用率将新能源可信出力纳入备用,建立多电源电力生产模型。所建模型以生产成本最小为目标函数,考虑电源运行成本、新能源弃电成本、切负荷惩罚成本及机组出力、功率平衡、逻辑变量等约束条件。采用时间迭代将中长时间生产模拟化简为短期优化问题,利用CPLEX求解。以改进IEEE-24节点系统作为算例,优化结果表明新能源电源采用实时备用率的方法纳入备用时,电力系统生产运行总成本更低;新能源渗透率越高,纳入新能源为备用的经济效益越明显;风电和光伏独立确定备用率时,备用成本和污染排放更低。

适应新型电力系统的电力互替品市场——(二)商品形态及形成机理

当前的电力现货市场基础理论是在新能源占比极低情况下提出的,其所依据的“分时交易”假设无法适应新型电力系统新能源占比日渐趋高、调节需求日益增加的新情况。为此,文中舍弃“分时交易”的基本假设,将功率曲线作为有机整体进行交易,探讨商品形态及形成机理。首先,分析对比“分时交易”与系列论文提出的“整体交易”中商品的形态,揭示“分时交易”中电力商品在各时段同质的假设在实际中不能成立的根本原因。其次,从市场组织者角度出发,探讨电力互替品的性质与形成过程,指出电力除具备生产使用价值外,还具有平衡价值,并定义互替电量、调节电量分别对这两种价值进行表征与量化。进而,从市场主体角度出发,以电力互替品的形成成本最小为目标,提出市场主体自主优化形成电力互替品的方法。进一步指出,各主体还可互补聚合形成电力互替品,适应海量分散的新型市场主体进入市场。最后,算例从量、质、价三个方面展示电力互替品的形成过程,分析了影响电力互替品形成成本的关键因素。电力互替品的形成过程,正是市场主体从计划式的“被动提供灵活性”变为市场化的“主动提供灵活性”的过程,也正是系统调节能力的挖掘提升过程。

新型电力系统应对极端事件的风险防范与应急管理关键技术

保障电力安全是贯彻落实总体国家安全观的基本要求。当前,我国电力系统正向新型电力系统演进,新能源不确定性、设备低抗扰与弱支撑性等特征变化叠加日益严峻的极端事件威胁,使得提升电力系统弹性、防范电力安全风险成为一项复杂且具有挑战性的工作。该文在详细介绍新型电力系统弹性提升所面临挑战的基础上,从“风险评估—投资规划—预防准备—响应恢复”4个层面归纳新型电力系统应对极端事件的电力风险防范与应急管理技术,系统分析各层面的关键技术与研究重点。最后,对保障新型电力系统电力安全的实现路径进行展望,提出进一步深入研究的方向。

可再生能源综合系统现状与未来发展趋势研究

通过分析中国能源结构现状与能源转型面临的主要挑战,结合未来能源需求,研究适合中国国情的低碳、低成本的能源转型现实路径,提出以可再生能源为主体、多能源互补、“冷热电”联供、集“源网荷”于一体的新型能源系统解决方案——可再生能源综合系统;然后对可再生能源综合系统的现状与关键技术进行了研究,并分析了其未来发展趋势。研究结果表明:围绕用户侧构建分层次、分场景的以可再生能源为主体的集“冷热电”“源网荷”于一体的新型能源系统,是中国实现能源转型的系统解决方案。

促进我国可再生能源发展的税收政策研究

大力发展可再生能源是推进能源革命的客观要求,而我国可再生能源发展面临既要大规模开发,又要高水平消纳,更要保障电力安全可靠供应等多重挑战,因而亟需充分发挥税收政策的激励作用。现行税收政策在促进可再生能源开发、利用以及新型电力系统核心技术创新等方面仍然存在一些不足之处。未来需要从优化可再生能源开发的增值税和企业所得税优惠政策、出台可再生能源消纳利用的税收支持政策、加大新型电力系统核心技术创新税收支持力度等方面,完善支持绿色低碳发展的税收政策体系,促进我国可再生能源高质量发展。

考虑新能源随机性的新型电力系统图深度学习稳定指标概率分布评估模型

新型电力系统的新能源大规模随机性出力特点导致目前在线暂态稳定扫描结论面临失效风险,这一问题从元件建模精度、系统拓扑适应性和计算速度三个方面同时对现有方法提出挑战。因此提出了基于重概率化改进的置信带方法和图深度学习的稳定指标概率分布及置信带评估模型,通过图深度学习模型快速评估少量采样点,再由重概率化置信带方法扩增结果,利用标签共现知识引导时域仿真对准确率进行增强,最后使用置信带方法给出随机出力下的稳定概率分布和区间形式的评估结论。该方法优点在于利用了图深度学习的拓扑适应能力和快速计算特点,且不受元件建模精度限制,置信带计算结论具有可靠的理论背景,能够评估稳定概率分布。在IEEE-39和IEEE-300节点系统上的评估精度验证表明,所提方法能够高精度地预测指定方式暂态稳定指标,并给出可靠的概率评估结论。

水电高占比下风电接入对系统稳定性影响

随着绿色清洁高效能源基地的构建,以水电为主体的水风互补成为我国西南能源开发的重要特征。为研究在典型水电系统中接入风电对系统稳定性带来的影响,首先,针对水风互补系统以转矩分析法分析了风电接入对系统频率和功角稳定性的影响,并通过算例和Prony分析验证了风速与风电渗透率对系统稳定性的影响。结果表明,风电的接入在一定程度上可以削弱传统水电系统的超低频振荡,而风电接入互联送端系统会导致区域等值惯量的下降,进而使系统区域间低频振荡风险加剧。其次,考虑风电的接入会诱发区域间低频振荡,在风电系统中引入风电的附加综合虚拟惯性与阻尼控制。算例与Prony分析验证了该控制策略能有效提高系统稳定性。最后,在区域间大规模风电接入场景下,利用改进的鲸鱼算法对风电的附加控制器参数进行了优化;结果表明,参数的整定有效提高了系统的频率以及功角稳定性。

适应新型电力系统的多维协同电力市场体系

构建适应新型电力系统的电力市场体系,既是实现能源电力转型的必然要求,也是实现“碳达峰·碳中和”目标的重要途径。在全面分析新型电力系统结构改变给电力系统带来的变化与挑战的基础上,构建了适应新型电力系统的目标、时间、空间、价值、主体多维协同的电力市场体系。围绕安全保供、低碳转型与经济的多目标协同,中长期、现货与实时运行的多时间协同,多层次全国统一电力市场的多空间协同,安全-绿色-经济的多价值协同,新型市场主体快速发展下的多主体协同五方面关键问题,提出了多维协同的市场设计思路和核心机制。最后,给出了建设全国统一电力市场的实施路径和建议。