110kV电缆终端塔支架平台设计改进

通过某种电缆终端塔在运行中出现的问题,对塔材的布置形式和受力进行了分析,找出故障的根本原因,提出设计改进措施,供设计运行人员参考。     

精密微细漆包线产品的节能工艺改造

苏州圣利线缆有限公司是一家专业生产漆包铜圆线的企业,原生产设备能耗高、不环保。企业通过采用二次触媒催化燃烧技术对漆包工艺进行技术改造,降低用电单耗,提高生产效率,消除了污染排放,提升了产品的市场竞争力,节电效果十分明显。     

投影能量函数在天津电网在线安全分析的应用

介绍了投影能量函数理论在天津电网在线安全分析系统中的应用.利用投影变换,将复杂的故障后电力系统动态过程转化为相点在一维空间中的简单运动进行研究.通过研究故障后系统最小投影动能与失稳发电机组有功出力之间的关系,提出一种计算暂态稳定约束下发电极限的方法.该方法已应用于天津电网在线安全分析系统中,对有危害故障提供预防控制调整方案.在华北2007年方式计算电网上的分析结果表明了该算法的有效性.     

广东电网光传输色散受限系统研究

随着电网业务的不断拓展,电力通信传输系统的传输速率越来越高、距离越来越长。如何在高速率长距离的情况下,保证传输信号的质量已经成为当务之急。文章介绍了高速率、长距离情况下的光传输色散受限系统,并结合广东电网的实际线路,对色散补偿技术进行实例分析,解决了现网中出现的一些线路故障,为今后电力专网工程建设和维护提供技术指导。     

新型电励磁磁通切换电机励磁绕组结构分析

励磁绕组连接方式对电励磁磁通切换电机电磁特性影响很大。对所提出的2种新型电励磁磁通切换电机,分析了其工作模式和“磁通切换原理”,利用有限元分析方法比较了2种电机的电磁特性：定子磁链、反电势、气隙磁密、定位力矩、电磁转矩、转矩密度。重点比较了励磁绕组连接方式对电机漏磁和功率密度的影响。结果表明,电励磁磁通切换电机具有较高正弦度的双极性磁链和全周期工作模式,适合运行在无刷交流场合。拓扑2具有更小的漏磁和更高的励磁电流利用率,其转矩密度为拓扑1的2倍。分析结果为所提出电励磁磁通切换电机在航空起动／发电机系统、风力发电系统等领域的应用提供了理论背景。     

An innovative technique to evaluate network equivalent for voltage stability assessment in a widespread sub-grid system

The equivalent two-bus network models currently available are obtained by lumping all the series impedances and shunt admittances of transmission lines within a series equivalent impedance, to assess voltage stability of multi-bus power system. This paper reports the development of an equivalent pi-network model using a new methodology considering series and shunt parts of line loss separately obtained from the operational parameters of optimal power flow solution of the original multi-bus power network, which can be applied to assess the overall voltage stability status of the system accurately by developing the concept of a generalized global voltage stability margin (GVSM). Simulation results for a typical longitudinal power supply (LPS) system and a robust practical (Indian Eastern Grid) system establish that the pi-equivalent model obtained by the proposed method is highly promising for assessing voltage stability of any power system at any operating point in global scenario in a better way as compared to available series equivalent model. Continuation power flow (CPF) method has also been adopted here to verify the potential of the proposed method for voltage stability assessment. In the proposed equivalent network the generators have been modeled more accurately considering optimal operating criteria.     

Prediction parameters of dimensioning of insulators under non-uniform contaminated conditions by multiple regression analysis

Surface tracking on solid insulators is one of the most severe breakdown mechanisms. Accurate assessment of real insulation conditions can be achieved by using the statistical techniques that assist the measurement and monitoring of contamination severity, flashover voltage and leakage current.To address the uncertainties that surround the exact physical mechanisms underlying the mathematical models, it has been shown that it is possible to include in the assessment of insulator performance contamination accumulation that is predicted by using a short historical of chemical components and atmospheric conditions. The results from this work are useful to predict the contamination severity, flashover voltage as a function of contamination severity, leakage current as a function of applied voltage, arc length and contamination severity, and especially to predict the flashover current.     

基于可靠性的配电网规划思路和方法 讲座六 可靠性与费用的关系

规划人员在考虑配电网应具有良好的可靠性时,面临的主要挑战是如何处理可靠性与费用的关系。基于可靠性规划最终的问题就是要在定额资金的范围内获得尽可能高的供电可靠性,或以尽可能少的费用获得特定水平的供电可靠性。重点介绍了基于成本效益的可靠性改进方法(CERI),是能有效处理可靠性与费用关系的一种方法,该方法简单实用、无需建模和复杂计算。介绍了可靠性的投资分配的基本概念以及CERI的6个基本步骤,最后给出了一个应用示例。     

电网故障诊断的一种完全解析模型

现代大规模互联电网提高了电力系统运行的稳定性和经济性,同时也给电网的故障诊断增加了难度。对电网保护配置和断路器动作规则进行深入分析,提出一种新的电网故障诊断模型——完全解析模型,并为基于此模型的故障诊断提出一种实用有效的求解方法。在完全解析模型中,故障假说（即可疑故障设备的故障情况）与保护、断路器的动作情况及拒动和误动情况一同表示成逻辑变量,而保护配置和断路器动作规则以逻辑方程组形式进行充分表达,逻辑方程组的每个解析解对应一个故障模式（设备故障状态和保护动作、断路器跳闸状态及拒动/误动情况）,是对故障情形的完整解释。本模型对故障诊断规则和保护、断路器的动作逻辑进行完全解析,并完整保留了故障设备、保护动作和断路器跳闸之间的耦合关系,克服了已有解析模型的缺陷。算例表明,保留完整耦合关系的完全解析模型可有效提高故障诊断的准确性和容错能力。     

基于轨迹灵敏度的模型参数校正方法研究

针对大规模电力系统数值仿真参数的校正,采用轨迹灵敏度分析获得对系统轨迹影响较大的参数,以缩小误差参数的搜索范围。对已经选择出来的待校正参数集,可采用非线性最小二乘法和粒子群算法识别待校正参数值。仿真实验表明：两种算法具有各自的优势和不足。