半波长线路过电压分析与保护方法

Overvoltage Analysis and Protection Method for Half-wavelength Lines

半波长线路的输电距离远,电气特征与现有特高压线路存在较大差异。由于线路沿线电压最大值位置在线路中间,常规的过电压保护无法满足半波长线路的要求。本文对半波长线路稳态运行电压特性做了深入的分析,研究了半波长线路稳态运行过电压的影响因素,并推导出了线路沿线电压最大值位置与线路功率传输的关系。在此基础上,提出了一种适用于半波长线路的过电压保护方法。EMTP仿真表明,该方法可以准确计算出沿线电压最大值,并保护线路全长。

The transmission distance of half-wavelength lines is comparatively longer,therefore,their electrical charac？teristics are obviously different from those on the existing high-voltage transmission lines.As the position of the maxi？mum voltage locates in the middle of transmission lines,the conventional over-voltage protection cannot satisfy the re？quirement of half-wavelength lines.In this paper,the steady-state voltage characteristics of half-wavelength lines are ana？lyzed in depth,and the influencing factors of over-voltage of half-wavelength lines under steady-state operation are stud？ied.In addition,the relationship between the maximum voltage position and line transmission power is deduced.On this basis,an overvoltage protection method for half-wavelength lines is proposed. EMTP simulations show that this method can accurately calculate the maximum voltage along the transmission line and protect the full length of the line .