Effects of un-transposed UHV transmission line on fault analysis of power systems     

王安宁  陈青  周占平 《天津大学学报(英文版)》2008,14(3):231-234

The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method with the symmetrical distributed parameter circuit model as the equivalent circuit of the un-transposed ultra high voltage (UHV) transmission line were studied under both normal operation and fault, and the corresponding problems arising were pointed out. By contrast with electromagnetic transient and power electronics (EMTPE) simulation results with the asymmetrical distributed parameter circuit model of un-transposed line, it is shown that the conventional method cannot show the existence of negative and zero sequences before fault happening and there are many errors on voltage and current after fault happening which are different with fault types. The error ranges of voltage and current are 2.13%-81.13% and -7.82%-86.15%, respectively.  相似文献   

如何将物理语言转化成物理过程     

周占平 《中学生数理化(高中版)》2010,(6):80-81

在物理解题中很多同学有同样的感受,拿来题的时候不会做,无法下手,当老师讲解时就容易听懂,或是老师提示一下就明白了.这种问题的原因是自己看题时挖掘不出有用的条件,不能将题目给出的物理语言转化成物理过程和已经学习过  相似文献