Results 31 to 40 of about 26,852 (162)
提出了一种由直流后备式熔断器和直流真空负荷开关串联组成的直流组合电器,对其直流开断特性进行了仿真和实验研究。新型直流组合电器可完成直流电流的全范围开断:当开断额定电流和过载电流时,采用真空直流负荷开关利用人工电流过零法开断电流,此时后备式熔断器不动作;当开断大过载电流和短路电流时,采用后备式直流熔断器直接开断大电流,也可以将大电流限制至较低幅值再采用真空直流负荷开关进行分断。实验结果证明,该直流真空负荷开关可以在5 ms内成功开断200 A至1.7 k A的直流电流,直流后备式熔断器可以开断1.7 k ...
刘思远 +7 more
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Studies on the Anodic Oxidation of Aluminum (I) : Anodic Oxidation of Aluminum in Aqueous Solutions Containing Sulfuric Acid and Some Organic Acids [PDF]
Anodic oxidation of aluminum in aqueous solutions containing sulfuric acid and one of various organic acids was examined. The organic acids used were sulfosalicylic acid, salicylic acid, benzoic acid and benzenesulfonic acid.
新美 洪一 +2 more
core +1 more source
ABSTRACT Photocatalytic molecular oxygen (O2) activation provides a sustainable approach to produce singlet oxygen (1O2) for organic contaminants detoxification. However, the charge carriers‐involved pathway usually suffers from unsatisfactory 1O2 production efficiency owing to energy loss caused by photogenerated hole‐mediated superoxide species (•O2−
Yan‐Biao Shi +8 more
wiley +1 more source
直流滤波器是特高压直流输电工程直流场重要成套设备之一,笔者在总结前期特高压直流输电工程系统研究结论的基础上,研究分析了+800 kV特高压直流输电工程直流滤波器设计需要考虑的关键问题,包括滤波器形式,直流侧谐振,要考虑的典型故障;介绍了用于计算直流滤波器典型故障的模型和方法。以云广+800 kV特高压直流输电工程为例,对直流侧谐振进行了校核,对直流滤波器设备暂态定值进行了计算。研究结果表明,云广±800 kV特高压直流输电工程直流滤波器设计是合理的,可满足直流系统安全可靠运行要求。
田邑安, 张万荣, 行鹏, 胡宇
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On the Characteristics of the Transistor, and the Mechanisms of the Operation of Transistor Chopper [PDF]
On the basis of Ebers-Moll equations of the transistor, I have studied the methods for the indication of the characteristics of the transistor, with aid of the X-Y recorder.
中川 孝之
core +1 more source
ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao +11 more
wiley +1 more source
换流站直流转换开关及直流旁路开关的操作机构大多由交流断路器改造而来,其防跳回路按照固定开关于分闸状态的原则设计,并不能完全适应直流系统的运行要求。文章概述了直流转换开关及直流旁路开关的结构及原理,从直流系统运行要求、最大转换电流及转换失败要求两个方面,分析了直流转换开关及直流旁路开关的设备运行要求。基于配合保障直流系统可靠性和可用率的要求分析了常规直流转换开关及旁路开关防跳回路设计存在的不足,指出直流转换开关和旁路开关的防跳设计应遵从固定于合闸状态的原则,并给出了防跳回路的改进设计。
余爽 +6 more
doaj
The study of bidirectional DC-DC converter in the DC microgrid [PDF]
作为新能源的有效利用方式之一的直流微电网没有无功功率的损耗,不需要跟踪频率和相位,可靠性和可控性有较大程度的提高,更适合分布式能源的接入和应用。双向DC-DC变换器承担着母线与储能之间能量双向流动的重要作用。同时,它还可以作为直流微电网之间的互联元件,具有十分重要的研究价值。 本文针对全桥拓扑结构的双向DC-DC变换器展开较为深入的研究。 首先,详细分析了在移相控制方式下,双向DC-DC变换器的在降压方向和升压方向的工作原理及零电压开关(ZVS,Zerovoltageswitching)的具体过程 ...
纪承承
core
ABSTRACT With the continuous advancement of materials science and technology, the rare metal gallium has increasingly emerged as a promising alternative to the toxic metal mercury. Although existing research has predominantly focused on the high electrical conductivity and excellent deformability of liquid metal (LM), its intrinsic fluidic property ...
Feifan Guo +6 more
wiley +1 more source
介绍了直流输电工程采用的直流滤波器的类型与构成,分析了±800 kV特高压直流输电工程换流器在直流侧产生的谐波的特点,并与±500 kV高压直流输电工程做了比较。以实际的±800 kV特高压直流输电工程为例,对换流器在直流线路上产生的等效谐波干扰电流进行了计算,对不同直流滤波器设置方案下的滤波效果进行了比较,并以计算结果为依据提出了较为合理的±800 kV特高压直流输电工程直流滤波器设置方案,为最终确定实际工程直流滤波器方案具有一定的参考作用。
张万荣, 任军辉, 王蔚华
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