架空送电线路临界档距及其判别

在输电线路工程设计中，电线应力计算与气象条件和代表档距有关。往往在不同的代表档距范围内要选用不同的气象条件和控制应力进行计算，这就提出一个不同档距范围的分界点即所谓临界档距的问题。由于临界档距的概念比较抽象，因此判别起来不是很直观。从理论分析的角度对临界档距的概念、计算公式的推导和判别方法作出详细的阐述，供输电线路设计人员参考。

Critical Span and Its Determination for Over-head Transmission Lines

In the design of transmission lines, the stress of a transmission line depends on both span and the weather conditions in the area. The stress is usually calculated based on different weather conditions for different spans. As a result, the problem of critical span appears. The existing critical span is difficult to determine since its concept is metaphysical. The concept of critical span and its calculation formula are presented in detail in this paper to offer reference for designers.