【作者】 凌代俭；

【导师】 卫志农；

【作者基本信息】 河海大学 ， 机械电子工程， 2001， 硕士

【摘要】 本文主要论述了电力系统中母线上发生三相对称短路时，其动稳定和热稳定的校验问题。 首先，对于电源容量为“无限大”的系统中发生三相对称短路时，短路电流及其峰值出现时间进行了数值计算和分析，讨论了短路电流计算中的几个基础性的理论问题，并得到了一些新的结论。 其次，在电路中短路电流计算的基础上，（1）进行母线的短路动稳定校验计算：采用模拟退火算法（SA算法）计算了矩形母线短路电动力的最大值及其取极值的条件，获得了更为一般的结果，进而通过短路电动力的频谱分析，给出了铜质母线的有关短路校验计算数据；（2）进行母线的短路热稳定校验计算：讨论了热稳定校校的几种常用计算方法，从导体或电器的发热机理出发，运用人工神经网络理论对母线的热稳定问题进行计算，通过算例比较，证明该方法用于热稳定计算是可行的。 最后，讨论了电力系统谐波的产生原因及其危害，分析了电力谐波对短路动稳定校验的影响，通过对含有谐波的短路电动力的频谱分析，得到相应的动稳定校验参数。更多还原

【Abstract】 This paper discusses the short-circuit verifying of wires in dynamic stability and heat withstand while the wires are chosen in the design of power system.Firstly, the numerical analysis on the short-circuit currents and their time appearing maximum values is taken in the three-phase symmetry short-circuit of "infinity" system in power capacity. Some new conclusions are got after discussing some basic theoretical questions.Secondly, the following two subjects are discussed according to the calculation of short-circuit current: (l)To verify the dynamic stability condition of wires by using simulated annealing algorithm (SA), the paper calculates the maximum value of rectangle wires’ short-circuit electrodynamic stress and gets the conditions of their having the maximum value. Furthermore, some concerned data about the verifying of copper wires are given by analysing vibration spectrum of the electrodynamic stress; (2)In order to get the heat withstand conditions of wires, the paper discusses some common calculation methods, and then tries to study the problem applying artificial neural network (ANN) based on heat principle of metals. The model is shown to be feasible.Finally, the headwaters of harmonic current and its harms to power system are discussed, the influences of harmonic currents to short-circuit verifying are analyzed, some parameters are gained according to the analyse on vibration spectrum of the electrodynamic stress.更多还原