超高压线路近端故障的快速距离保护

提出了一种针对超高压线路近端故障的快速距离保护新算法.该方法利用积分算法响应速度快、计算工作量小的特点,基于微分方程模型,结合工频变化量原理,有效地实现了超高压长线路近端故障的正确快速动作.基于RTDS数模仿真平台,对500 k V线路的多种故障形式进行了数模仿真试验,验证了该算法在超高压线路近端故障时可靠快速的动作性能.     

基于干扰观测器的多光伏光柴混合系统协调控制研究

提出了一种基于干扰观测器的多光伏光柴混合系统协调控制方法,并与采用最大功率跟踪控制而不加协调的多光伏系统的供电效果进行了对比.仿真结果证明,该方法减小了光柴混合系统的频率偏差,并且使各个光伏系统获得了较大功率输出.     

含分布式能源的配电网规划

概述了分布式电源对配电网的影响,分析了分布式电源在配电网中的优化配置以及含分布式能源的配电网的无功优化模型,总结了在规划过程中的算法,最后针对配电网的规划提出了相关建议.     

四角切圆煤粉锅炉燃烧温度场的数值模拟

四角切向燃烧煤粉锅炉的炉内过程是一个非常复杂的湍流流动与燃烧化学反应过程.利用流体力学软件"F luent"对此锅炉燃烧情况进行数值模拟,得出炉内的温度场.通过对锅炉燃烧温度场的模拟预测温度场的趋势,结果完全符合炉膛燃烧的规律.锅炉燃烧温度场的模拟对于锅炉的安装和改造有指导意义.     

交直流配电网中电动汽车充换储一体站规划

首先,以马尔可夫和速度-流量模型对快充车辆和电动公交进行时空负荷预测,结合快充站、换电站和梯级储能站的充放电功率构建充换储一体站(CSSIS)模型.然后,建立含CSSIS的交直流潮流模型,构建计及电动汽车到站行驶时间、排队等待时间和交直流配电网电压偏差的多目标选址模型,采用动态权重结合二进制遗传算法进行求解.其次,采用Voronoi图划分CSSIS服务范围,以综合投资成本最小为目标建立优化模型来确定最终站址,通过排队论优化充电机数量,以系统节点电压和CSSIS功率平衡为约束来确定站内设备容量.最后,通过算例验证了所提模型和方法的有效性.     

水平管内流型转换区湿气流经多孔板的压降特性

较之于传统的单孔板,多孔板有压损系数小、整流、低噪声等多方面优点,在湿气流量测量中具有重要应用价值。以空气和水为两相工质,在水平管内湿气流型转换区对小孔分别呈圆形和矩形的2个多孔板的压降特性进行了实验。结果表明:圆孔、槽孔多孔板的湿气压降特性无明显差别;多孔板的气相压降倍率与气相、液相弗劳德数均密切相关;与实验结果相比,现有均相流模型的预报结果均偏高,现有分相流模型的预报结果均偏低;通过气相、液相弗鲁德数双参数对孔板湿气压降模型进行修正,可明显提高压降关联式的预报准确度;基于均相流模型双参数修正所得的多孔板压降关联式的预报精度最优,对圆孔多孔板、槽孔多孔板的预报偏差分别在±7%、±10%以内。     

基于相变蓄热技术的高过载配电变压器研制与应用

本文中作者提出了一种基于相变蓄热技术的高过载变压器,采用石蜡蓄热方式显著提升其抗过载发热能力,并通过试验验证了其实用价值。     

基于数字化工厂的制造业信息化集成平台

分析了现代制造企业信息化平台的问题,研究了数字化工厂DFS功能特点,及其在CAX / PDM /ERP信息系统平台中的必要性,提出了完整的制造企业信息化集成平台,探索了基于数据库的数字化工厂系统与PDM系统间的集成技术.     

Comparative study of bis-piperidiniummethyl-urea and mono-piperidiniummethyl-urea as volatile corrosion inhibitors for mild steel

Bis-piperidiniummethyl-urea (BPMU) and mono-piperidiniummethyl-urea (MPMU) were developed as novel volatile corrosion inhibitors (VCIs). Their vapor corrosion inhibition property was evaluated by volatile inhibiting sieve test (VIS) and vapor inhibiting ability test (VIA). Volatile weight-loss test in a closed space was used to compare their volatility. Electrochemical impedance spectroscopy of a volatile corrosion inhibitor monitor (VCIM) was applied to study the effect of BPMU and MPMU on the corrosion inhibition of mild steel in thin electrolyte layer. The results show that BPMU has the better protection effect compared with MPMU. Adsorption of BPMU and MPMU on steel surface was investigated by X-ray photoelectron spectroscopy (XPS). It was shown that one BPMU molecule has two N atoms to coordinate with one Fe atom, and that one MPMU molecule has one N atom to coordinate with one Fe atom. The quantum chemical parameters were obtained by PM3 semi-empirical method. BPMU has the smaller HOMO-LUMO energy gap and the smaller net positive charge intensities of 4N and 8N atoms in its molecule.     

A novel electrochemical testing method and its use in the investigation of the self-repairing ability of temporarily protective oil coating

A novel electrochemical method using a wire beam electrode was developed to investigate self-repairing ability of temporarily protective oil coating. Results showed that inhibited oil coatings had the ability of self-repairing, and oil-soluble inhibitors had direct effect on the self-repairing ability of oil coating. The degradation processes that were related to the underfilm corrosion of oil coating could also be realized by investigating the self-repairing ability of oil coating.