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基于支路暂态能量函数的特高压区域电网间容量交换能力研究 被引量:5
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作者 云雷 刘涤尘 +2 位作者 廖清芬 汪如松 黄涌 《电力自动化设备》 EI CSCD 北大核心 2012年第3期7-12,共6页
随着特高压电网的逐步建成,大区电网间必将存在大容量的有功功率传输,提出基于支路暂态能量函数的分析方法对电网间极限交换容量进行计算分析。在多机系统COI坐标系统方程的基础上构建电力系统支路暂态能量函数模型,并验证了系统扰动后... 随着特高压电网的逐步建成,大区电网间必将存在大容量的有功功率传输,提出基于支路暂态能量函数的分析方法对电网间极限交换容量进行计算分析。在多机系统COI坐标系统方程的基础上构建电力系统支路暂态能量函数模型,并验证了系统扰动后的总暂态能量守恒的原则,通过电网中各支路能否消纳发电机转子动能来判定系统的稳定性。在CEPRI 8机36节点系统中对扰动后网络中各区域支路的暂态能量函数分布特性进行了验证分析,并在此基础上求出电网区域间最大传输功率。应用该方法对电网间的极限交换容量进行校核计算。仿真结果验证了该方法的有效性。 展开更多
关键词 支路暂态能量 容量交换能力 能量守恒 特高压输电 暂态分析
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基于改进电压灵敏度分析的大区电网间容量交换能力评估 被引量:3
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作者 董飞飞 刘涤尘 +4 位作者 吴军 黄涌 宋春丽 赵一婕 潘旭东 《电网技术》 EI CSCD 北大核心 2013年第7期1862-1867,共6页
提出基于断面交换容量–电压变化比的灵敏度分析方法,对大区电网间潮流断面上的交换容量–电压稳定性进行分析,得出系统薄弱通道和敏感节点。对基于交换容量最敏感节点的电压灵敏度变化趋势进行样条插值,对样条插值所得的离散值进行非... 提出基于断面交换容量–电压变化比的灵敏度分析方法,对大区电网间潮流断面上的交换容量–电压稳定性进行分析,得出系统薄弱通道和敏感节点。对基于交换容量最敏感节点的电压灵敏度变化趋势进行样条插值,对样条插值所得的离散值进行非齐次指数函数拟合后求导,得出电压灵敏度的变化率函数,根据电压稳定临界点的判别条件计算交换容量极限,并以电压稳定裕度指标进行校验。对"三华"特高压电网的容量交换能力评估的应用表明,所提方法正确、有效,且具有较高的精度。 展开更多
关键词 电力系统 静态电压稳定 改进电压灵敏度 电压稳定裕度 容量交换能力
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基于静态频率稳定性分析的电网容量交换能力评估 被引量:3
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作者 董飞飞 《陕西电力》 2013年第1期1-5,共5页
电力系统静态频率特性识别与计算对于维持电力系统稳定具有十分重要的意义。使用最小二乘法对仿真计算得到的静态频率特性系数进行曲线拟合,依据拟合得到的静态频率特性系数的曲线变化趋势预测不同交换容量下的频率偏差限制点,在静态频... 电力系统静态频率特性识别与计算对于维持电力系统稳定具有十分重要的意义。使用最小二乘法对仿真计算得到的静态频率特性系数进行曲线拟合,依据拟合得到的静态频率特性系数的曲线变化趋势预测不同交换容量下的频率偏差限制点,在静态频率稳定性分析的基础上进行电网容量交换能力评估。通过算例仿真验证了该方法的有效性。 展开更多
关键词 电力系统 频率稳定 静态频率特性系数 曲线拟合 容量交换能力
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Continuous Separation of Cesium Based on NiHCF/PTCF Electrode by Electrochemically Switched Ion Exchange 被引量:1
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作者 孙斌 郝晓刚 +3 位作者 王忠德 张忠林 刘世斌 官国清 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第5期837-842,共6页
Nickel hexacyanoferrate (NiHCF) film was synthesized on porous three-dimensional carbon felt (PTCF) substrate by repetitious batch chemical depositions, and the NiHCF/PTCF electrode was used as electrochemically switc... Nickel hexacyanoferrate (NiHCF) film was synthesized on porous three-dimensional carbon felt (PTCF) substrate by repetitious batch chemical depositions, and the NiHCF/PTCF electrode was used as electrochemically switched ion exchange (ESIX) electrode in a packed bed for continuous separation for cesium ions. The morphologies of the prepared electrodes were characterized by scanning electron microscopy and the effects of solution concentration on the ion-exchange capacity of the electrodes were investigated by cyclic voltammetry technique. Cycling stability and long-term storage stability of NiHCF/PTCF electrodes were also studied. The NiHCF/PTCF electrodes with excellent ion-exchange ability were used to assemble a diaphragm-isolated ESIX reactor for cesium separation. Continuous separation of cesium and regeneration of NiHCF/PTCF electrode based on the diaphragm-isolated reactor were performed in a laboratory-scale two-electrode system. 展开更多
关键词 nickel hexacyanoferrate electrochemically switched ion exchange cesium separation porous carbon felt
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Use of Mussel Shells as a Soil Amendment:Effects on Bulk and Rhizosphere Soil and Pasture Production 被引量:10
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作者 E.LVAREZ M.J.FERNNDEZ-SANJURJO +1 位作者 N.SECO A.NUEZ 《Pedosphere》 SCIE CAS CSCD 2012年第2期152-164,共13页
Large quantities of mussel shells (66000-94000 t year^-1), an alkaline material that can be used as a soil amendment, are generated as waste in Galicia, NW Spain. A field trial was carried out by planting different ... Large quantities of mussel shells (66000-94000 t year^-1), an alkaline material that can be used as a soil amendment, are generated as waste in Galicia, NW Spain. A field trial was carried out by planting different pasture species in a Haplic Umbrisol using a randomized block design with four blocks and six treatments (not amended control or soil amended with lime, finely ground shell, coarsely ground shell, finely ground calcined shell or coarsely ground calcined shell) to compare the effects of lime and mussel shells additions on a soil with a low cation exchange capacity and high AI saturation. The trial was established in March 2007, and samples of plants and soil were collected when plots were harvested in summer 2008 (separating the bulk and rhizosphere soil). The soils were analyzed for pH, total C, total N, available P, exchangeable cations, effective cation exchange capacity and available micronutrients. Dry matter yield was measured in all plots and plants were analyzed for nutrients. Application of mussel shells and the commercial lime resulted in an increase in pH and exchangeable Ca and a decrease in exchangeable Al and Al were most noticeable in the rhizosphere. The amendment of Ca in the plant. saturation. The stability of pH over time was high. These effects also had a positive effect on dry matter yield and concentration 展开更多
关键词 dry matter production exchangeable A1 LIMING pasture quality soil nutrients
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Retention and Mobility of Copper and Lead in Soils as Influenced by Soil Horizon Properties
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作者 B.CERQUEIRA E.F.COVELO +1 位作者 M.L.ANDRADE F.A.VEGA 《Pedosphere》 SCIE CAS CSCD 2011年第5期603-614,共12页
The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption phenomena.Cu2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitant... The mobility and bioavailability of heavy metals in soils is largely governed by sorption and desorption phenomena.Cu2+ and Pb2+ are among the most potentially toxic heavy metals and they are present,often concomitantly,in many polluting spills and in agrochemicals.The objective was to assess and compare the competitive sorption and desorption capacities and sorption hysteresis of Cu2+ and Pb2+,as well as their migration through the profiles of four natural soils:a Humic Umbrisol,an Umbric Cambisol,an Endoleptic Luvisol and a Humic Cambisol.In all horizons Pb2+ was invariably sorbed and retained to a greater extent than Cu2+.The sorption and retention of Cu2+ were most in?uenced by pH,e?ective cation exchange capacity(CECe) and Mn oxide content.On the other hand,the fixation capacity of Pb2+ was most in?uenced by pH,CECe,and Mn oxide and organic matter contents.pH and CECe were the individual soil properties most markedly in?uencing Cu2+ and Pb2+ sorption and retention.In all the horizons Pb2+ exhibited greater hysteresis than Cu2+.In each soil the hysteresis in the A horizon was greater than that in the B horizon,except in the Bt horizon of the Endoleptic Luvisol,due to its high pH and vermiculite content.Based on migration indices,Pb2+ was less mobile than Cu2+ in the studied soils. 展开更多
关键词 DESORPTION heavy metal HYSTERESIS migration SORPTION
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