半波长输电系统运行特性的全电磁暂态仿真研究

Electromagnetic Transient Simulation of Operating Characteristics of UHV AC Half-wavelength Transmission System

为了同时准确模拟半波长输电线路波传播过程及其落点电网的运行特性，建立了含特高压半波长输电工程的华东大规模交直流混联电网的全电磁暂态仿真模型，建立其稳态运行方式，研究了半波长线路稳态运行特性；通过模拟半波长输电线路区内故障和区外交直流电网发生的严重故障，分析了半波长输电系统暂态运行特性及其与交直流相互影响。研究表明，半波长线路区内故障比区外故障对电网系统的影响更加严重，线路的首端和末端发生故障时，发生换相失败的直流回数和次数较多，故障后系统均能恢复稳定运行；半波长线路安装避雷器后能够提高系统的稳定性，减少直流换相失败的回数和次数，提高线路的输送能力。

In order to simulate the wave propagation process of half wave-length AC transmission （HWACT） lines and the operating characteristics of its connected power grids accurately and simultaneously, we established whole electromag- netic transient simulation model of HWACT and large scale AC/DC hybrid power grid in East China. Moreover, we established the steady-state operation mode, and simulated the steady-state operation characteristics of the HWACT line. By simulating the faults in the HWACT line and the faults of the AC/DC power grid, the transient operating characteris- tics of the HWACT and its interaction with AC and DC were analyzed. Research shows that the fault of HWACT lines is more serious than fault of power system; the system can be restored to stable operation after the failure. When the fault occurs at both ends of the line, the times of commutation failures are higher. After installing arresters on HWACT lines, the stability of the system can be improved, the times of DC commutation failures can be reduced, and the transmission capacity of the lines can be improved. This paper provides a research method for HWACT technology.