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特高压输电线路端电压控制域的计算方法研究 被引量:3
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作者 陈霞 孙海顺 +5 位作者 隋先超 文劲宇 李小平 孙建波 李淼 李大虎 《电力系统保护与控制》 EI CSCD 北大核心 2011年第6期45-49,共5页
采用特高压现有无穷大电势源等值法获取端电压二维控制域时,会得出投入容性无功补偿将降低特高压沿线电压这一'错误'结论,对此研究证明:变压器中压侧绕组等效阻抗为负是造成二维电压运行下限上移的主要原因。提出了一种新的等... 采用特高压现有无穷大电势源等值法获取端电压二维控制域时,会得出投入容性无功补偿将降低特高压沿线电压这一'错误'结论,对此研究证明:变压器中压侧绕组等效阻抗为负是造成二维电压运行下限上移的主要原因。提出了一种新的等值电势源法,即将华中电网和华北电网分别等效成含内阻抗的电势源。采用该等值方法时,无功补偿装置的投切所引起的电压控制域的变化趋势与电压无功理论相符,同时还可以考虑线路输送功率变化时,由线路功率和两端母线电压共同形成的三维控制域。 展开更多
关键词 特高压输电 端电压控制域 母线电压法 等值电势源 三维控制域
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Numerical modeling of the 2D time-domain transient electromagnetic secondary field of the line source of the current excitation 被引量:4
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作者 刘云 王绪本 王贇 《Applied Geophysics》 SCIE CSCD 2013年第2期134-144,235,共12页
To effectively minimize the electromagnetic field response in the total field solution, we propose a numerical modeling method for the two-dimensional (2D) time- domain transient electromagnetic secondary field of t... To effectively minimize the electromagnetic field response in the total field solution, we propose a numerical modeling method for the two-dimensional (2D) time- domain transient electromagnetic secondary field of the line source based on the DuFort- Frankel finite-difference method. In the proposed method, we included the treatment of the earth-air boundary conductivity, calculated the normalized partial derivative of the induced electromotive force (Emf), and determined the forward time step. By extending upward the earth-air interface to the air grid nodes and the zero-value boundary conditions, not only we have a method that is more efficient but also simpler than the total field solution. We computed and analyzed the homogeneous half-space model and the fiat layered model with high precision--the maximum relative error is less than 0.01% between our method and the analytical method--and the solution speed is roughly three times faster than the total-field solution. Lastly, we used the model of a thin body embedded in a homogeneous half-space at different delay times to depict the downward and upward spreading characteristics of the induced eddy current, and the physical interaction processes between the electromagnetic field and the underground low-resistivity body. 展开更多
关键词 Time-domain transient electromagnetics secondary field DuFort-Frankel finite-difference method numerical modeling.
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Electricity Sector Transitions in an after War Country: A Review of Afghanistan's Electricity
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作者 Mir Sayed Shah Danish Najib Rahman Sabory +4 位作者 Sayed Mir Shah Danish Tomonobu Senjyu Gul Ahmad Ludin Ahmad Samim Noorzad Atsushi Yona 《Journal of Energy and Power Engineering》 2017年第7期491-496,共6页
Afghanistan electricity sector has experienced many ups and downs of transitions from 1893 to date. With the growing global interest in Afghanistan rehabilitation, this paper presents an over view of Afghanistan elect... Afghanistan electricity sector has experienced many ups and downs of transitions from 1893 to date. With the growing global interest in Afghanistan rehabilitation, this paper presents an over view of Afghanistan electricity sector which includes the historical development trends, power generation potential, sustainable energy exploitation, electricity policy transition and immature policies experiences, and the legacy of the war. The lack of access to the basic information about Afghanistan power sector was one of the serious concerns of international donors and investors. Still, this information somehow has been kept in official documents wrap up. In this collection, the Afghanistan's electricity sector is pictured as a reference for Afghanistan electricity. It can be opening toward primary sources of Afghanistan electricity sector of the lessons learned and asset for researchers interesting in this topic. 展开更多
关键词 Afghanistan electricity electricity sector development Afghanistan renewable energy
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Electricity Sector Development Trends in an After-war Country: Afghanistan Aspiration for an Independent Energy Country
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作者 Mir Sayed Shah Danish Najib Rahman Sabory +4 位作者 Sayed Mir Shah Danish Tomonobu Senjyu Gul Ahmad Ludin Ahmad Samim Noorzad Atsushi Yona 《Journal of Energy and Power Engineering》 2017年第8期553-557,共5页
The rapid change in economic growth and human civilization has led to a dramatic increase in energy utilization and electricity demand. That faces nations with the challenge of maintaining cost-effective and clean pow... The rapid change in economic growth and human civilization has led to a dramatic increase in energy utilization and electricity demand. That faces nations with the challenge of maintaining cost-effective and clean power energy production. This paper aims to present Afghanistan electricity sector development and energy resources exploitation in a broad context. With the global growing interest in Afghanistan rehabilitation, this paper presents energy development trends in Afghanistan. Besides, the future outlook up to 2032 and the challenges that face electricity sector are highlighted. This study tries to emerge the historical development, current status, and future direction of Afghanistan electricity sector till 2032, in a precise collection. 展开更多
关键词 Afghanistan electricity electricity development trends electricity sector challenges electricity policy.
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电机检修工(高级)技能鉴定内容及要求
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《云南电业》 2004年第6期47-47,共1页
直流电路。鉴定比重:3。(1)掌握星形和三角形电阻连接的等效变换:(2)能用电势源和电流源的等效变换、结点电位法及戴维南定理分析求解简单的电阻电路。
关键词 大型电机 检修 直流电路 电势源 电流 电机检修工 技能鉴定
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