半波长交流输电的串并联补偿仿真分析

现有研究结论认为半波长交流输电线路本身无需安装无功补偿设备，然而稳态运行时半波长交流输电沿线电压分布具有其特殊性。过电压的极值和出现位置与输送功率、功率因数等密切相关。本文首先采用特高压交流线路工程参数，通过数字仿真手段分析了半波长交流线路的沿线电压分布特性，在电压和电流相量图的辅助下，着重研讨了在半波长交流线路的两端而不是线路本身进行串联补偿和并联补偿来改善沿线电压分布特性、减少线路损耗的可行性。仿真分析结果表明：半波长交流输电线路两端是需要无功补偿的；串联补偿和并联补偿都能降低半波长线路的线损率，还能改变半波长沿线电压分布；与常规线路不同，半波长线路的并联补偿能更有效地抑制稳态过电压，控制更简单。

Simulation and analysis of series and parallel compensation of half wavelength ac transmission system

The results of existed study show that there is no requirement for reactive compensation by Half Wavelength Al-ternating Current Transmission (HWACT) lines themselves. However, the characteristics of steady-state voltage distribution of HWACT lines are distinctive. The over-voltage maximum and its position are closely related with both transmission power and power factor. In this paper, based on parameters of existed ultra-high voltage AC transmission lines, steady-state voltage distribution characteristics of an HWACT line are firstly analyzed through digital simulation. Then with the aid of the voltage and current phasor diagram, both series compensation and shunt compensation at the terminals of the HWACT line instead of itself are proposed to improve the voltage distribution characteristics and to reduce power losses. The simulation and analysis results finally show that there are re-quirement for reactive compensation at the terminals of HWACT lines. Both series compensation and shunt com-pensation might reduce the power losses of the HWACT lines and modify the steady-state voltage distribution. The shunt compensation is more effective and easier to mitigate the steady state over-voltage of the HWACT line than the series compensation.