区域模型软件CFAST(Consolidated Model of Fire Growth and Smoke Transport)是经过美国核管会检验和验证的五款可用于核电评估的火灾模拟软件之一。本文针对火灾条件下的电缆温升,考虑了电缆芯的材料热特性,提出了改进的电缆温度预测...区域模型软件CFAST(Consolidated Model of Fire Growth and Smoke Transport)是经过美国核管会检验和验证的五款可用于核电评估的火灾模拟软件之一。本文针对火灾条件下的电缆温升,考虑了电缆芯的材料热特性,提出了改进的电缆温度预测一维热传导模型。同时,针对ICPMP(International Collaborative Project to Evaluate Fire Models for Nuclear Power Plant Applications)标准实验5种火灾工况,通过该实验的数据对改进模型进行了验证,得到了其优于原模型结论。展开更多
高压电力电缆接头温度是反映电缆运行状况的重要指标,对接头温度进行精确预测可提高电缆安全运行水平。采用最小二乘支持向量机建立适用于电缆接头的温度预测模型,并给出了预测方法的具体步骤。模型以电缆接头的历史温度、环境温度、湿...高压电力电缆接头温度是反映电缆运行状况的重要指标,对接头温度进行精确预测可提高电缆安全运行水平。采用最小二乘支持向量机建立适用于电缆接头的温度预测模型,并给出了预测方法的具体步骤。模型以电缆接头的历史温度、环境温度、湿度和线芯/护层电流比为输入样本,电缆接头的表面温度为输出。为了提高预测精度,采用粒子群优化算法对模型的标准化参数和正则化参数进行动态寻优。以上海某110 k V电缆接头为例进行预测,结果表明,提出的方法能较好地预测电缆接头温度,预测精度高,为电缆温度监测和预警系统提供可靠的判断依据。展开更多
In this paper a methodology is proposed to model the stochastic electro-thermal degradation accumulation in cables.The cable life and the reliability are predicted by estimating the accumulated electro-thermal degrada...In this paper a methodology is proposed to model the stochastic electro-thermal degradation accumulation in cables.The cable life and the reliability are predicted by estimating the accumulated electro-thermal degradation during seasonal load cycles.The degradation is considered,in a novel approach,as stochastic in nature due to variations in the manufacturing process of insulation raw material and in operational and environmental conditions.The methodology is based on estimation of life by using combined electro-thermal life model,simulation of degradation accumulation process under electro-thermal stress in each season of the year based on Miner’s cumulative damage theory and reliability prediction from a probabilistic point of view.A case study is demonstrated on 10 k V XLPE cables which are directly buried in the UK and China.Results show that,the electro-thermal life of the cable is 56 and 69 years in China and the UK,respectively at 50%failure probability,or the life of the cable in the UK would be 13 years longer than in China,when other stresses such as mechanical and environmental are also considered and assumed to be the same.展开更多
文摘区域模型软件CFAST(Consolidated Model of Fire Growth and Smoke Transport)是经过美国核管会检验和验证的五款可用于核电评估的火灾模拟软件之一。本文针对火灾条件下的电缆温升,考虑了电缆芯的材料热特性,提出了改进的电缆温度预测一维热传导模型。同时,针对ICPMP(International Collaborative Project to Evaluate Fire Models for Nuclear Power Plant Applications)标准实验5种火灾工况,通过该实验的数据对改进模型进行了验证,得到了其优于原模型结论。
文摘高压电力电缆接头温度是反映电缆运行状况的重要指标,对接头温度进行精确预测可提高电缆安全运行水平。采用最小二乘支持向量机建立适用于电缆接头的温度预测模型,并给出了预测方法的具体步骤。模型以电缆接头的历史温度、环境温度、湿度和线芯/护层电流比为输入样本,电缆接头的表面温度为输出。为了提高预测精度,采用粒子群优化算法对模型的标准化参数和正则化参数进行动态寻优。以上海某110 k V电缆接头为例进行预测,结果表明,提出的方法能较好地预测电缆接头温度,预测精度高,为电缆温度监测和预警系统提供可靠的判断依据。
文摘In this paper a methodology is proposed to model the stochastic electro-thermal degradation accumulation in cables.The cable life and the reliability are predicted by estimating the accumulated electro-thermal degradation during seasonal load cycles.The degradation is considered,in a novel approach,as stochastic in nature due to variations in the manufacturing process of insulation raw material and in operational and environmental conditions.The methodology is based on estimation of life by using combined electro-thermal life model,simulation of degradation accumulation process under electro-thermal stress in each season of the year based on Miner’s cumulative damage theory and reliability prediction from a probabilistic point of view.A case study is demonstrated on 10 k V XLPE cables which are directly buried in the UK and China.Results show that,the electro-thermal life of the cable is 56 and 69 years in China and the UK,respectively at 50%failure probability,or the life of the cable in the UK would be 13 years longer than in China,when other stresses such as mechanical and environmental are also considered and assumed to be the same.
