Results 1 to 10 of about 997,849 (169)
考虑谐波谐振和电压稳定的海上风电场无功优化配置方法 [PDF]
海上风电经长距离高压交流海底电缆接入电网,海底电缆容升效应显著,容易引起工频过电压,同时电力电子器件和线路电容引起的谐波谐振问题也严重影响着电网电能质量,因此进行海上风电场无功配置时应充分考虑过电压和谐波谐振问题。针对上述问题,建立了海上风电场谐波模型,对海上风电场的谐波模态阻抗进行扫描,继而分析海上风电场的谐振特性;然后研究了海上风电场无功特性,计算各种发电出力水平和并网点电压下的风电场无功缺额;接着以降低综合成本为目标,以静态电压稳定裕度、最小补偿容量、谐波谐振及过电压为约束 ...
马明, 梅桂华, 杜婉琳*, 王玲
core +1 more source
张北可再生能源柔性直流电网工程投运以来,交直流系统中数次出现次、超同步振荡问题。对2022年某日振荡发生时现场录波采集到的交直流振荡波形数据进行分析,录波数据分析表明,交流侧的次同步(43.75 Hz)、超同步(56.25 Hz)振荡,在dq坐标系下均表现为6.25 Hz振荡,同时在直流电压和直流电流中也出现了6.25 Hz的振荡频率。初步判断振荡发生的原因是:风电场功率快速变化时,站间骤然变化的直流电压引起了直流电流发生振荡,直流电流通过直流通路造成MMC子模块电容电压产生振荡 ...
林畅 +5 more
core +1 more source
带电更换1000 kV耐张绝缘子时的工器具和人体电场分布研究
利用组合工器具带电更换1 000 kV耐张绝缘子会改变绝缘子串的电压分布、影响带电工作人员体表电场分布,为分析绝缘子串不同位置进行更换作业时的整体电压和电场分布规律,文中根据实际1 000 kV耐张塔输电线路建立了三维模型,利用有限元法进行电场仿真分析;并使用子模型法重点分析了组合工具在不同位置时工具本体的最大电场值,以及人体在不同位置使用组合工具时的体表场强分布。分析结果表明,组合工具越靠近导线端,对绝缘子的电位分布及人体电场分布的影响越大,与没有组合工具短接绝缘子时进行比较,从铁塔端到靠近导线端 ...
普子恒 +4 more
doaj
近年来电池储能以其响应速度快、能量密度高等优点,在电力系统中发挥重要作用。为满足实际应用的要求,电池储能系统需要将电池或电池组并联从而达到较高的可用容量,但并联电池在实际中受内阻、容量、荷电状态 (SOC)等影响将出现电流不平衡现象,一定程度上制约了电池充放电电流和使用条件,影响了电池性能。针对并联电池组支路电流采集过程繁琐且状态估计复杂的情况,以电池的二阶等效电路为基础,结合回路电流法建立了并联电池组的仿真模型。模型能够根据锂电池的性能参数及状态方程实现并联支路电流的计算,进而估计并联电池组的状态 ...
张彩萍 +5 more
core +1 more source
Political Cycles, Electricity Policy, and Mexico's Economy
ABSTRACT Electricity reform in Mexico should stimulate economic growth, improve energy efficiency, and reduce greenhouse gas emissions. This article evaluates the successes and failures of reform and draws lessons across political cycles by analyzing changes in political dynamics—often tied to policy reversals—and the legal framework during the pro ...
David Bonilla
wiley +1 more source
电力市场的目标、结构及中国电力市场建设的关键问题讨论 [PDF]
中国电力改革与市场化建设逐步进入深水区,面临着多方面目标难以协调、不同阶段的改革目标不一致、电力市场设计缺乏整体性与系统性等问题。首先提出和分析了电力市场的终极目标和路径目标,将社会福利分配结构纳入市场结构中形成广义的市场结构概念,然后结合中国国情讨论了如何通过市场设计让市场和政府协调发挥作用,最后对中国当前电力市场建设中的中长期与现货市场衔接、省内与省间市场衔接、计划与市场衔接等关键问题进行了分析,并给出了建议的解决思路。从经济学角度分析、讨论中国电力市场改革面临的一些关键问题,旨在寻求长期的 ...
肖谦, 喻芸, 荆朝霞
doaj +1 more source
ABSTRACT The Janus structure of ZnIn2S4 (ZIS) endows it with an intrinsic built‐in electric field that effectively drives photogenerated charge separation. However, this very structure also renders the predominant (001) facet (In–S termination) catalytically inert due to its low electron density and high energy barrier for the hydrogen evolution ...
Qingao Zhou +8 more
wiley +1 more source
ABSTRACT Piezocatalytic technology utilizes mechanical strain or stress‐induced piezoelectric phenomena to produce robust internal electric fields, markedly improving the separation efficiency of e−‐h+ pairs. This method has emerged as a focal point in catalysis by removing reliance on conventional light or electrical energy via its mechanical‐to ...
Yue Zhou +5 more
wiley +1 more source
Fermi Surface Structure Revealed by Quantum Oscillations in Half‐Heusler Semimetal LuAuSn
ABSTRACT The Fermi surface structure in the half‐Heusler semimetallic compound LuAuSn was systematically investigated using quantum oscillation studies of high‐quality single crystals and first‐principles calculations. Clear bulk quantum oscillation signals were observed for multiple complementary physical properties, including magnetization, Hall ...
Yue Lu +12 more
wiley +1 more source
ABSTRACT Narrowband near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) featuring low full‐width at half maximum (FWHM) and high conversion efficiency are crucial for chemical content evaluation, light therapy, and bioimaging.
Chunshen Li +4 more
wiley +1 more source

