Earth energy evolution, human development and carbon neutral strategy

Energy is the basis of human development and the impetus of society progress. There are three sources of energy: energy of celestial body outside the Earth, the Earth energy and energy of interaction between the Earth and other celestial bodies. Meanwhile, there are three scales of co-evolution: the evolution of the Sun-Earth-Moon system on an ultra-long time scale has provided energy sources and extra-terrestrial environmental conditions for the formation of the Earth system;the evolution of the Earth system on a long time scale has provided the material preconditions such as energy resources and suitable sphere environment for life birth and the human development;on a short time scale, the development of human civilization makes the human circle break through the Earth system, expanding the extraterrestrial civilization. With the co-evolution, there are three processes in the carbon cycle: inorganic carbon cycle, short-term organic carbon cycle and long-term organic carbon cycle, which records human immoderate utilization of fossil energy and global sphere reforming activities, breaking the natural balance and closed-loop path of the carbon cycle of the Earth, causing the increase of greenhouse gases and global climate change, affecting human happiness and development. The energy transition is inevitable, and carbon neutrality must be realized. Building the green energy community is a fundamental measure to create the new energy system under carbon neutrality target. China is speeding up its energy revolution and developing a powerful energy nation. It is necessary to secure the cornerstone of the supply of fossil energy and forge a strong growing pole for green and sustainable development of new energy. China energy production and consumption structure will make a revolutionary transformation from the type of fossil energy domination to the type of new energy domination, depending on a high-level self-reliance of science and technology and a high-quality green energy system of cleaning, low-carbon, safety, efficiency and independence. Energy development has three major trends: low-carbon fossil energy, large-scale new energy and intelligent energy system, relying on the green innovation, contributing the green energy and constructing the green homeland.

Application of Fault Location Mode Based on Travelling Waves for Neutral Non-effective Grounding Systems

Fault location for distribution feeders short circuit especially single-phase grounding fault is an important task in distribution system with non-effectively grounded neutral.Fault location mode for distribution feeders using fault generated current and voltage transient traveling waves was investigated.The characteristics of transient traveling waves resulted from each short circuit fault and their transmission disciplinarian in distribution feeders are analyzed.This paper proposed that double end travelling waves theory which measures arriving time of fault initiated surge at both ends of the monitored line is fit for distribution feeders but single end traveling waves theory not.According to different distribution feeders,on the basis of analyzing original traveling waves reflection rule in line terminal, Current-voltage mode,voltage-voltage mode and current-current mode for fault location based on traveling waves are proposed and aerial mode component of original traveling waves is used to realize fault location.Experimental test verify the feasibility and correctness of the proposed method.

Progress, challenge and significance of building a carbon industry system in the context of carbon neutrality strategy

Carbon dioxide storage and utilization has become an inevitable trend and choice for sustainable development under the background of global climate change and carbon neutrality.Carbon industry which is dominated by CO_(2) capture,utilization and storage/CO_(2) capture and storage(CCUS/CCS)is becoming a new strategic industry under the goal of carbon neutrality.The sustainable development of carbon industry needs to learn from the experiences of global oil and gas industry development.There are three types of“carbon”in the earth system.Black carbon is the CO_(2) that has not been sequestered or used and remains in the atmosphere for a long time;grey carbon is the CO_(2) that has been fixed or permanently sequestered in the geological body,and blue carbon is the CO_(2) that could be converted into products for human use through biological,physical,chemical and other ways.The carbon industry system covers carbon generation,carbon capture,carbon transportation,carbon utilization,carbon sequestration,carbon products,carbon finance,and other businesses.It is a revolutionary industrial field to completely eliminate“black carbon”.The development of carbon industry technical system takes carbon emission reduction,zero carbon,negative carbon and carbon economy as the connotation,and the construction of a low-cost and energy-efficient carbon industry system based on CCUS/CCS are strategic measures to achieve the goal of carbon neutrality and clean energy utilization globally.This will promote the“four 80%s”transformation of China's energy supply,namely,to 2060,the percentage of zero-carbon new energy in the energy consumption will be over 80%and the CO_(2) emission will be decreased by 80%to ensure the carbon emission reduction of total 80×10^(8) t from the percentage of carbon-based fossil energy in the energy consumption of over 80%,and the percentage of CO_(2) emission from energy of over 80%in 2021.The carbon industry in China is facing three challenges,large CO_(2) emissions,high percentage of coal in energy consumption,and poor innovative system.Three strategic measures are proposed accordingly,including:(1)unswervingly develop carbon industrial system and ensure the achievement of carbon neutrality as scheduled by 2060;(2)vigorously develop new energy sources and promote a revolutionary transformation of China’s energy production and consumption structure;(3)accelerate the establishment of scientific and technological innovation system of the whole CO_(2) industry.It is of great significance for continuously optimization of ecological environment and construction of green earth and ecological earth to develop the carbon industry system,utilize clean energy,and achieve the strategic goal of global carbon neutrality.

Major biological events and fossil energy formation: On the development of energy science under the earth system framework

In geological history, one major life explosion and five mass extinction events occurred. These major biological and environmental events affected the evolution of the Earth ecosystem and controlled the formation of organic-rich strata. The life explosion occurred in Cambrian and the five mass extinction events happened at the end of Ordovician, Late Devonian, end of Permian, end of Triassic, and end of Cretaceous, respectively. They are corresponded to the formation of multiple suites of organic-rich strata globally, which are crucial to the formation, evolution and distribution of the fossil energy on Earth. China’s energy is characterized by "unlimited new energy, rich in coal but insufficient in oil and gas ", and it is determined to rely on new energy sources to achieve " energy independence " and carbon neutrality. From the perspective of the Earth system evolution, we investigate the multiple relationships between energy and Earth, energy and environment, as well as energy and human beings, and carry out comprehensive research on energy. Energy science refers to the science of studying the various energy sources formation and distribution, evaluation and selection, production and utilization, orderly replacement, development prospects, etc. in temporal and spatial scales based on the evolution of the Earth system. The connotation of energy science includes three core contents:(1) The relationship between the Earth and energy, including the formation of energy in the Earth system and the feedback of energy consumption to the Earth’s climate and environment;(2) The relationship between the Earth environment and the human beings, including the Earth environment breeding human beings and human activities transforming the earth environment;(3) The relationship between the energy and the human beings, including the development of energy technology by human beings and the progress of human society driven by energy utilization. The energy science focuses on the formation and development of fossil energy, development and orderly replacement of new energy, exploration and utilization of energy in deep earth and deep space, and energy development strategy and planning. The proposal of energy science is of great significance for improving the discipline system, promoting energy development, clarifying the development direction of energy transition, driving the carbon neutral geology research and constructing a habitable Earth.

Estimate Totel Number of the Earth Atmospheric Particle with Standard Atmosphere model

The total number of atmospheric particle (AP) is an important datum for planetary science and geoscience. Estimating entire AP number is also a familiar question in general physics. With standard atmosphere model, considering the number difference of AP caused by rough and uneven in the earth surface below, the sum of dry clean atmosphere particle is . So the whole number of AP including water vapor is . The rough estimation for the total number of AP on other planets (or satellites) in condensed state is also discussed on the base of it.

Over Voltage Fault due to Disconnection of Consumer’s Transformer Neutral Wire

Practically,the load currents in three phases are asymmetric in the power system.It means that the impedances are different in all three phases.If the consumer’s transformer neutral cut off and/or was disconnected from the neutral of power supply source,then there will be some trouble and failure occurred.The current in the neutral wire drops down to zero when the neutral wire is cut off and the phase currents of all three-phase equal to each other since there was no return wire.The currents are equal but the voltages at the phase consumers are different.Especially for residential single-phase consumers,the voltage at the consumers of the phase varies differently for three phase systems when the neutral wire was disconnected at consumer side and even the voltage at the consumers one or two of those three phases becomes over nominal voltage or reaches nearly line voltage.In this case,the electronic appliances in that phase will be fed by high voltage than the rated value and they can be broken down.In the power system of UB(Ulaanbaatar)city,there are some occasional such kind of failures every year.Obviously,many electronic appliances were broken down due to high voltage and the electricity utility companies respond for service charge of damaged parts.

从离子型稀土镁盐富集物中提取稀土工艺初探

以MgO为沉淀剂沉淀MgSO_(4)稀土浸出母液时,得到的稀土镁盐富集物REO总量较低,需要进一步除去杂质以沉淀富集稀土。以离子型稀土镁盐富集物为原料,进行碳化—酸溶—中和除杂—沉淀等工艺初步探索研究。结果表明:REO在碳化过程中的损失很少甚至可以忽略不计,有24.33%~30.9%MgO由稀土镁盐富集物转化进入碳化后液,在中和除杂过程中Fe去除率约99.5%,Al去除率约98.6%。以碳化后液为沉淀剂沉淀中和除杂后液得到碳酸稀土,经过灼烧,获得了符合《GB/T 20169—2015离子型稀土矿混合稀土氧化物》标准质量要求的稀土氧化物,该工艺总渣率为19.81%~23.22%,REO总收率平均89.43%。为了从离子型稀土镁盐富集物中提取稀土的工艺形成成套工艺技术,获取最优的工艺技术参数,有待于后续深入研究和优化。

A Novel Single Phase Grounding Fault Protection Scheme Without Threshold Setting for Neutral Ineffectively Earthed Power Systems

The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes.When the detected feature parameter value exceeds the setting value,the protection will trip.However,the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems(NIEPS)due to wide variations in operating conditions and the complexities of fault cases.In this paper,a novel single phase grounding fault protection scheme without threshold setting is proposed.The fault detection is achieved based on operating states rather than setting values.A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states.The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space.The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated.If the distance to the fault state is shorter than that to the non-fault state,a fault is detected.Otherwise,the feeder is considered normal.A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions,non-linear loads,and complex fault cases.Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.

Fault Feeder Identification in Non-effectively Grounded Distribution Network with Secondary Earth Fault

Secondary earth faults occur frequently in power distribution networks under harsh weather conditions.Owing to its characteristics,a secondary earth fault is typically hidden within the transient of the first fault.Therefore,most researchers tend to focus on a feeder with single fault while disregarding secondary faults.This paper presents a fault feeder identification method that considers secondary earth faults in a non-effectively grounded distribution network.First,the wavelet singular entropy method is used to detect a secondary fault event.This method can identify the moment at which a secondary fault occurs.The zero-sequence current data can be categorized into two fault stages.The first and second fault stages correspond to the first and secondary faults,respectively.Subsequently,a similarity matrix containing the time-frequency transient information of the zero-sequence current at the two fault stages is defined to identify the fault feeders.Finally,to confirm the effectiveness and reliability of the proposed method,we conduct simulation experiments and an adaptability analysis based on an electromagnetic transient program.

矿山供电系统单相接地故障区段定位方法

中性点非有效接地的矿山高压供电系统发生单相接地故障后,故障暂态过程交叉干扰严重,故障信号呈现出很强的非线性、非平稳性、高时变性和复杂性,故障定位难度很大。针对此难题,提出了一种基于分布散度的故障区段定位方法。首先,通过等效电路分析了故障特性,研究并采用Choi-Williams分布(Choi-Williams Distribution,CWD)时频能量谱克服故障信号中多频率成分交叉干扰。然后,采用改进KL散度表征故障区段上下游信号时频分布差异,处理上下游信号CWD时频能量谱中重叠部分,消除故障区段上下游信号相似成分的不利影响。在此基础上,借助零序电流信号CWD-KL散度构建了故障定位判据。最后,仿真测试与对比分析验证了所提方法的有效性与优越性。

面向高电缆化率配电网的中性点接地技术探讨

随着城镇化的飞速发展,配电网系统的电缆比例不断提高,电缆开始逐渐替代传统的架空线路。然而,现有许多变电站的中性点接地方式仍基于纯架空线路设计,难以适应高电缆化率配电网系统的需求。文章针对配电网中性点接地方式进行了系统研究,详细阐述其类型、特性以及对电力系统的作用。针对高电缆化率配电网,提出中性点接地方式的选择建议,为保障配电网的安全稳定运行提供参考。

一起10 kV单相接地引发三相短路故障的辨识与分析

针对一起10 kV中性点非有效接地系统中由单相接地引发两相异地接地短路,最终发展为三相短路的事故案例,通过故障录波及现场故障信息情况进行辨识分析,得出了故障原因,并提出了防范措施及建议。

直流输电接地极对地表电位分布的影响

为消除直流输电的单极运行方式给我国交流电网的安全运行带来的威胁,采用有限元法分析了直流输电单极运行时接地极附近的地表电位分布特征,并通过简化的大地电阻率数学模型,定性分析了地形、大地各层电阻率、接地极设计和多个接地极共同作用等对地表电位分布的影响。因大地导电条件复杂,传统方法很难计算出有实际意义的可能流过变压器中性点的电流值,故根据等效阻抗的概念和逆向求解的思路,提出一种计算流过变压器中性点直流电流的新方法。

10kV电压互感器损坏的仿真计算研究

针对近年来提出的在中性点不接地系统中调节参数避免铁磁谐振的理论,分析中性点不接地电网发生单相接地时产生串联和并联谐振的条件,得出并联谐振电路能更好地反应系统的实际情况。在电力系统电磁暂态仿真软件(ATP-EMTP)中,按JDZJ-10电压互感器的试验参数进行仿真计算分析。仿真结果表明,减小10kV系统中的对地容抗参数不能避免谐振,只是谐波的次数更低,还会导致单相故障发生瞬间故障相电容上冲击电流增大和故障消失瞬间故障相的电压互感器的过电流增大。

检修的共用接地极线路分流电流实测分析

共用接地极在土地占用、建设投资等方面具有很好的经济性和使用价值。但共用接地极在检修和运行过程中可能会存在一些问题,特别是在接地极线路检修时,运行直流系统可能会出现不平衡运行或单极大地回线运行方式;检修接地极线路会有电流流过,对检修人员的安全造成威胁。为充分掌握检修的接地极线路电流分流水平,对3个共用接地极的6个换流站的接地极线路分别进行试验测量。通过统计比较的方法对测量数据进行分析,得到了接地极线路和换流变中性点的分流百分比以及分流电流的变化趋势;同时分析得出影响检修接地极线路分流电流的因素主要包括:挂接的检修接地的位置、接地极电阻、入地电流水平等。依据实测数据计算分析得到的结果,为共用接地极的直流系统检修时的运行方式安排提供了工程数据参考,对保障检修人员的安全具有重要意义。

基于TSC控制技术的快速响应自动消弧装置

自动消孤装置是由一种基于晶闸管投切电容(TSC)控制技术的自动调谐消弧线圈、接地变压器和互感器等组成的成套设备。它可对线路的单相接地故障做出快速响应,并精确补偿接地电流。此装置很好地解决了3个技术难点:第一,线路对地容抗的精确测量,误差在2%以下;第二,根据线路电容电流和人工中性点电压的变化来智能判别单相接地故障;第三,采取串联小电抗,过零投切和加装风机等措施,以确保晶闸管的安全运行。可编程逻辑控制器(PLC)、触摸屏式人机界面(HMI)和过零触发板构成了该装置的控制系统。模拟试验和实际应用表明该装置能够取得理想的效果。

中性点接地方式对供电可靠性的影响分析

单相接地占配网故障的80%,而中性点接地方式决定了单相接地故障的处理流程,对供电可靠性有决定性影响。文章针对中性点采用小电流接地、小电阻接地方式的架空线路网络与电缆网络,分析了接地方式影响配网供电可靠性的主要因素,建立了基于中性点接地方式的用户平均故障停电时间、用户平均故障停电次数、用户平均故障短时停电次数等供电可靠性指标的计算模型,并利用现场数据进行计算对比,旨在从供电可靠性方面为配电网中性点接地方式的选择提供参考。

碳中和背景下的水资源利用与保护

实现水资源高效智慧的利用与保护,是国家推进能源结构调整,促进低碳技术发展和环境保护,应对全球气候变化,实现“碳达峰、碳中和”战略目标的共性关键基础。为此,本文从水资源科技发展对碳中和的重大促进作用视角出发,回顾总结了水资源利用与保护的历史和战略发展趋势,阐明了水资源利用对开拓清洁能源应用潜力、促进国家能源结构低碳化的关键作用,研究了水资源利用与保护对于缩减碳源、提高碳汇的天然优势,并从规划运行智慧化、生态能源一体化、空间利用充分化、设计建造绿色化和改造发展统筹化等五大发展方向,系统凝练了智慧水利信息网络及反馈调控、多源信息监测体系及一体化模式、特殊地下空间利用及地下蓄能设施、生态水利工程及零碳水电站系统、中小型水电站改造并网及离网型水风光互补系统等高效智慧利用与保护水资源的技术方法。研究成果对长江黄河等重要流域保护、推进国家水资源利用重大战略工程实践、助力实现碳达峰、碳中和“3060”目标均具有重要促进意义。

用注入法实现小电流接地系统单相接地选线保护

介绍一种小电流接地系统单相接地选线的新原理，其适合小电流接地系统的各种情况，并通过实验室模拟试验，且已应用于８０９８单片机实现的微机选线保护。

配电混合线路双端行波故障测距技术

该文提出利用线路故障产生的暂态行波实现配电架空线、电缆混合线路单相接地及相间短路故障测距,分析了故障初始行波模分量的暂态特征。研究发现,尽管中性点非有效接地系统单相接地故障后线路稳态线电压保持不变,但其故障暂态过程仍产生行波线模分量,这样单相接地及相间短路故障均可利用参数比较稳定的行波线模分量作为测量信号。分析表明行波在配电混合线路传播过程中发生复杂的折、反射,应该利用双端行波测距法测量故障距离。针对架空线和电缆波速度不一致的问题,给出了基于时间中点的故障点搜索算法。分析了电压、电流行波在线路末端的反射规律,为选择合适的行波测量信号提供了理论基础。现场试验表明文中所述方法可行有效。