电解CO_2储存可再生电能的N-甲基吡咯烷酮/四丁基高氯酸铵电解液研究

将CO_2转化为甲醇,用作燃料或基础化工原料,是实现CO_2资源化利用的重要途径之一。研究设计了一种新型双室隔膜电解池,能够在N-甲基吡咯烷酮(NMP)/四丁基高氯酸铵(TBAP)溶液中,以可再生电能为能源,用电化学催化还原的方法将CO_2转化为CO,然后用工业制甲醇的传统方法将CO氢化还原为甲醇。循环伏安测试结果表明,CO_2在Au电极上发生了电还原反应;恒电位电解测试结果表明,阴极电流密度最高可达6.6 m A×cm^(-2);气相色谱检测结果表明,阴极气相反应产物主要为CO,生成CO的电流效率最高可达93%。由于CO_2电还原反应自身有H_2O生成,阴极表面有H2析出。扫描电镜(SEM)检测表明,Au电极表面没有附着物生成。在N-甲基吡咯烷酮/四丁基高氯酸铵溶液中电还原CO_2,具有电解液性质稳定、电极不中毒的优点,因而具有潜在的工业化应用前景。

电梯可再生电能评估与节电效果研究

在传统的电梯能耗模型的基础上引入工作场所、有效提升高度等影响因子，并结合统计学原理重新建模分析，提出一套科学、完整的电梯可再生电能的预测和评估方案，为建筑电气设计人员提供可靠的数据参考，为电梯节能的可行性、可观性提供技术支撑。

基于物联网的系统差动保护方法实现

介绍了对未来可再生电能传输与管理系统保护及运行改进,该系统使用固态变压器连接住宅交流和直流微电网到配电系统,并使用故障隔离设备隔离故障线路,提出一种电流差动保护方案来检测基于FREEDM的微电网网络中的故障,该方法使用相量测量单元进行数据同步并最小化测量误差,并采用物联网技术和Wi-Fi通信方案在设备间进行数据监测和互连。然后通过一个仿真FREEDM系统进行测试,在不同位置施加了不同类型和不同故障电阻的故障来证明所提出的保护方法在检测故障状态方面的有效性,利用安全性、可靠性和准确性指标对所提出方法的性能进行了调查。最后设计、实施和测试了FREEDM系统的原型,使用Proteus软件模拟器和实验室进行了测试。测试结果证明,所提出的保护方案以快速、可靠和准确的方式检测和隔离故障状态的效率,该保护方案对于所有故障实现了高达98.825%的准确率。

高压微网孤岛运行时频率稳定控制策略研究

当采用大量电力电子设备的微网孤岛运行时,使用P/f下垂控制存在负荷快速分配与频率稳定控制之间的矛盾,为此,提出改进的P/和Q/V下垂控制策略,将电压和相角偏差作为前馈量加入功率控制环节,实现电压和相角的二次调整,提高潮流变化时系统的动态适应性。仿真分析表明,所提出的控制策略不仅可实现负荷快速分配,而且相比P/f下垂控制具有更小的频率偏差,为高压微网孤岛运行时频率稳定控制提供了一种新方法。

应用于智能微网的SVPWM固态变压器研究

固态变压器(SST)是美国北卡大学所兴建的新型智能微网示范工程FREEDM的核心设备。本文以FREEDM的先进理念为背景,对SST的工作原理、主要创新功能和拓扑结构进行了分析,建立一个基于我国电力系统参数的三相交-直-交型SST模型,探讨该模型输入AC-DC整流单元、中间DC-DC变换单元和输出DC-AC逆变单元各部分的实现方式和控制策略,并引入空间电压矢量PWM(SVPWM)控制技术,提高SST的性能。通过Matlab/Simulink仿真分析表明,该SST模型能够实现单位输入功率因数和电能双向流动,输出三相工频正弦交流电压,具有良好的抗干扰性能,对FREEDM中国化具有重要意义。

孤岛微网中固态变压器间环流抑制研究

在未来可再生电能传输和管理微网(future renewable electric energy delivery and management,FREEDM)中固态变压器间会因输出电压偏差及输出阻抗的不匹配而产生环流,孤岛模式下尤为严重,为此,在下垂控制器中引入固态变压器(solid state transformer,SST)间输出电压偏差反馈调节,减小输出电压相角差和幅值差;采用基于模糊控制理论的瞬时环流反馈,进行动态虚拟阻抗调节,使得SST输出阻抗按额定功率精确匹配。仿真及分析表明,电压偏差反馈调节配合动态虚拟阻抗控制可以有效地抑制SST间环流,同时提高SST输出电压的稳定性。

我国电力能源现状及其发展趋势

“十五”以来,随着我国经济形势的迅猛发展,带动了电力行业在需求上的新变化。特别是今后几年、十几年,我国的电力需求和可再生电能的发展必将出现一个新的快速发展时期。

铜配合物衍生铜-氧化亚铜催化剂的原位电合成及其对二氧化碳电还原制备C2产物催化性能的研究

二氧化碳(CO2)是主要的温室气体,同时也是廉价、无毒、丰富、可再生的C1资源1。将CO2转化为高附加值化学品具有碳资源合理利用和环境保护双重意义,近年来引起国内外的广泛关注。然而,由于CO2热力学稳定、动力学惰性,其转化利用存在热力学和动力学的双重难题。采用电化学方法将CO2转化为液体燃料和高附加值化学品,是具有重要应用前景的技术路线之一2。随着可再生电能发电量不断增加,可以利用可再生电源将CO2转化为化学品和燃料,符合可持续发展的要求。目前,CO2电催化还原产物主要为C1产物,如CO、甲酸、甲醇等3–5。由于C–C偶联在电催化还原CO2过程中很难实现等原因,将CO2转化为C2产物比转化成C1产物难度大得多。

电动汽车碳排放计算与跟踪评估的探讨

电动汽车作为新能源的交通工具给人类社会提供新型驱动动力,同时减少二氧化碳排放;但电动汽车在制造以及使用过程中排放了多少二氧化碳,不同型号与驱动性能各异的电动汽车碳排放量能否到达国家碳排放减排要求?首先我们计算传统汽车与电动汽车的100公里碳排放,合理评估电动汽车使用中的碳排放,最后推导出一个电动汽车碳排放与跟踪评估公式;这一公式引入一个可再生能源用电系数,通过公式对比纯电动汽车与HEV在生命周期结束时二氧化碳排放情况。电动汽车能效的提升,充电电能来源追踪,这都需要综合考虑,以上可指导电动汽车类型选择及使用过程中碳跟踪与评估。

美国科学家利用微生物生产“纯”甲烷

大部分甲烷来自于天然气这种化石燃料。斯坦福大学和宾夕法尼亚州立大学的科学家正在采取更环保的方法,利用微生物将可再生电能转化为碳中和甲烷。

Thinking about Renewable Portfolio Standard to be Implemented in China

This paper briefs the basic objective of pursuing Renewable Portfolio Standard (RPS), puts forward a thinking about the scope and three modes of RPS-implementation in China and enumerates other possible measures, such as public bidding on concession, exemption from value-added tax, to promote wind power exploitation and development.

Advances in designing heterojunction photocatalytic materials

Under the background of increasing energy crisis and global warming,semiconductor-based photocatalysis has received tremendous attention due to its potential application in green energy production,CO_(2) reduction and pollutant degradation.The photocatalytic activity of semiconductors,however,remains low due to issues like fast recombination of photo-generated electron-hole pairs,limited electron mobility,restricted optical absorption or insufficient active sites.Designing appropriate heterojunctions is proved to be a promising method to address most of these issues and thus to improve the photocatalytic performance.In this review,the working mechanism of various heterojunctions is presented systematically.The most recent advances of strategies in designing and preparing efficient heterojunction photocatalysts are further summarized and some perspectives on the future directions in this field are provided.

Water electrolysis based on renewable energy for hydrogen production

As an energy storage medium,hydrogen has drawn the attention of research institutions and industry over the past decade,motivated in part by developments in renewable energy,which have led to unused surplus wind and photovoltaic power.Hydrogen production from water electrolysis is a good option to make full use of the surplus renewable energy.Among various technologies for producing hydrogen,water electrolysis using electricity from renewable power sources shows greatpromise.To investigate the prospects of water electrolysis for hydrogen production,this review compares different water electrolysis processes,i.e.,alkaline water electrolysis,proton exchange membrane water electrolysis,solid oxide water electrolysis,and alkaline anion exchange membrane water electrolysis.The ion transfer mechanisms,operating characteristics,energy consumption,and industrial products of different water electrolysis apparatus are introduced in this review.Prospects for new water electrolysis technologies are discussed.

Optimized PI controller for 7-level inverter to aid grid interactive RES controller

With the huge rise of energy demand,the power system in the current era is moving to a new standard with increased access to renewable energy sources(RESs)integrated with distribution generation(DG)network.The RESs necessitate interfaces for controlling the power generation.The multilevel inverter(MLI)can be exploited for RESs in two diverse modes,namely,the power generation mode(stand-alone mode),and compensator mode(statcom).Few works have been carried out in optimization of controller gains with the load variations of the single type such as reactive load variation in different cases.Nevertheless,this load type may be unbalanced hence,to overcome such issues.So,a sophisticated optimization algorithm is important.This paper aims to introduce a control design via an optimization assisted PI controller for a 7-level inverter.In the present technique,the gains of the PI controller are adjusted dynamically by the adopted hybrid scheme,grey optimizer with dragon levy update(GD-LU),based on the operating conditions of the system.Here,the gains are adjusted such that the error between the reference signal and fault signal should be minimal.Thus,better dynamic performance could be attained by the present optimized PI controller.The proposed algorithm is the combined version of grey wolf optimization(GWO)and dragonfly algorithm(DA).Finally,the performance of the proposed work is compared and validated over other state-of-the-art models concerning error measures.

Coping with climate change and China's wind energy sustainable development

Greenhouse gas emissions are the main cause of today's climate change. To address this problem, the world is in an era of new round energy transformation, and the existing energy structure is being reformed. In this paper, according to the Chinese government's action plan for coping with climate change, the China's wind energy sustainable development goals and development route are discussed, and the countermeasures and suggestions are put forward. Wind energy is currently a kind of important renewable energy with matured technology which can be scale-up developed and put into commercial application, and in this transformation, wind energy will play a key role with other non-fossil energy sources. The development and utilization of wind energy is a systematic project, which needs to be solved from the aspects of policy, technology and management. At present, China is in the stage of transferring from "large wind power country" to "strong wind power country", opportunities and challenges coexist, and the advantages of China's socialist system could be fully used, which can concentrate power to do big things and make contribution in the process of realizing global energy transformation.

Issues and Solutions for China's Photovoltaic Power Industry

Solar energy is an important renewable energy.Developing photovoltaic power will not only relieve the energy supply-demand contradiction and optimize the energy structure,but also help to restructure this industry.This paper analyzes the status quo and the development prospects of China's photovoltaic power industry and its existing issues,and puts forward some suggestions and solutions for its healthy and orderly development.

Safety and effective developing nuclear power to realize green and low-carbon development

This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety,environmental protection, enhancement of nuclear power technology, nuclear waste treatment, and disposal, as well as nuclear power plant decommissioning. Based on the safety record and situation of the existing power plants in China, the current status of the development of world nuclear power technology, and the features of the independently designed advanced power plants in China, this paper aims to demonstrate the safety of nuclear power. A nuclear power plant will not cause harm either to the environment and nor to the public according to the real data of radioactivity release, which are obtained from an operational nuclear plant. The development of nuclear power technology can enhance the safety of nuclear power. Further, this paper discusses issues related to the nuclear fuel cycle, the treatment, and disposal strategies of nuclear waste, and the decommissioning of a nuclear power plant, all of which are issues of public concern.

Perspectives of China’s wind energy development

Wind energy is a kind of clean renewable energy, which is also relatively mature in technology, with largescale development conditions and prospect for the commercialization. The development of wind energy is a systematic project, involving policy, law, technology, economy, society, environment, education and other aspects. The relationship among all the aspects should be well treated and coordinated. This paper has discussed the following relationships which should be well coordinated: relationship between wind resources and wind energy development, relationship between the wind turbine generator system and the components, relationship between wind energy technology and wind energy industry, relationship between off-grid wind power and grid-connected wind power, relationship between wind farm and the power grid, relationship between onshore wind power and offshore wind power, relationship between wind energy and other energies, relationship between technology introduction and self-innovation, relationship among foreign-funded, joint ventured and domestic-funded enterprises and relationship between the government guidance and the market regulation, as well as giving out some suggestions.

Energy Flexibility in the Power System： Challenges and Opportunites in Philippines

Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study to provide an overview of the current condition of the Philippines＇ power system and discuss the energy flexibility in the Philippines＇ power system. A further discussion and recommendation is conducted in the end of the paper.

Impact of renewable power market penetration on coal power generation capacity growth

Since renewable energy sources are growing in importance, how well they can penetrate the energy market for power generation will be a very important factor in the role the coal industry will play in the future. This paper examined the displacement of coal power plant capacity from 2010 to 2050 by renewables with respect to three drivers assumed under various conditions： the American Recovery and Reinvestment Act （ARRA）, Greenhouse Gas （GItG） policy, and varying plant capital cost cases. The results by 2050 illustrate that renewable market penetration captures anywhere from 1.9% to 6.4% of potential coal power generation capacity additions. Renewable power generation capacity additions is expected to outpace coal power plant additions by 89% with respect to ARRA in 2050, however with no GHG policy coal power generation capacity build-outs will outpace renewables by as high as 809%. Finally, coal power generation is still projected to be the largest single energy source contributor to the electricity market making up 28.0% of total available capacity, while renewables are expected to only make up 16.3% of total available capacity.