当配电系统三芯电缆因其他线路故障或电力抢修而需施加较大的应急负荷时,其线芯温度达到最高限值前,允许过载的时间是电缆运行监测部门亟待解决的问题。文中以10 k V三芯电缆为研究对象,首先建立电缆暂态热路模型,并将应急负荷作用下电...当配电系统三芯电缆因其他线路故障或电力抢修而需施加较大的应急负荷时,其线芯温度达到最高限值前,允许过载的时间是电缆运行监测部门亟待解决的问题。文中以10 k V三芯电缆为研究对象,首先建立电缆暂态热路模型,并将应急负荷作用下电缆暂态温升分为稳态分量和五个热时间常数不同的暂态分量。其次借助数据拟合的方法确定不同暂态分量的参数,得到应急负荷作用下电缆应急时间的计算表达式。最后设计了加载不同应急负荷时三芯电缆的暂态温升实验。实验结果表明,本方法能够准确地计算电缆的应急时间,为三芯电缆的应急能力评估和电力应急调度提供依据。展开更多
Long alumina .fibers with 60 cm in length were pre- pared by sol - gel method. The spinning sol was ob- tained by mixing aluminum nitrate, oxalic acid, and polyvinylpyrrolidone with a mass ratio of 10： 3： 2. Fourier...Long alumina .fibers with 60 cm in length were pre- pared by sol - gel method. The spinning sol was ob- tained by mixing aluminum nitrate, oxalic acid, and polyvinylpyrrolidone with a mass ratio of 10： 3： 2. Fourier transform infrared （ FTIR ） spectra, X-ray diffraction （XRD） , and scanning electron microscopy （SEM） were used to characterize the properties of the gel and ce- ramic fibers. The fibers with uniform diameter and smooth surface were obtained by sintering at 1 200℃ for 1 h, and their main phase was indentified as α-Al2O3.展开更多
文摘当配电系统三芯电缆因其他线路故障或电力抢修而需施加较大的应急负荷时,其线芯温度达到最高限值前,允许过载的时间是电缆运行监测部门亟待解决的问题。文中以10 k V三芯电缆为研究对象,首先建立电缆暂态热路模型,并将应急负荷作用下电缆暂态温升分为稳态分量和五个热时间常数不同的暂态分量。其次借助数据拟合的方法确定不同暂态分量的参数,得到应急负荷作用下电缆应急时间的计算表达式。最后设计了加载不同应急负荷时三芯电缆的暂态温升实验。实验结果表明,本方法能够准确地计算电缆的应急时间,为三芯电缆的应急能力评估和电力应急调度提供依据。
基金supported by the Natural Science Foundation of Shaanxi in China ( No. 2010K10 - 21)
文摘Long alumina .fibers with 60 cm in length were pre- pared by sol - gel method. The spinning sol was ob- tained by mixing aluminum nitrate, oxalic acid, and polyvinylpyrrolidone with a mass ratio of 10： 3： 2. Fourier transform infrared （ FTIR ） spectra, X-ray diffraction （XRD） , and scanning electron microscopy （SEM） were used to characterize the properties of the gel and ce- ramic fibers. The fibers with uniform diameter and smooth surface were obtained by sintering at 1 200℃ for 1 h, and their main phase was indentified as α-Al2O3.
