骨干网架电力恢复研究

Research on power restoration of backbone grid

电力系统恢复研究是保证电力故障区域快速、安全、稳定恢复的重要课题,其中电力线路恢复时的过电压校验是保证供电恢复方案是否可行的关键步骤。针对供电恢复路径恢复过程的过电压问题,利用仿真软件MATLAB/Simulink建立符合实际的仿真模型,研究骨干网架恢复供电路径时线路末端过电压幅值的影响因素。以大量仿真实验结果分析,验证了空载线路长度和三相非同期合闸及断路器三相非同期合闸对线路尾端过电压幅值的影响显著。并且基于仿真结果进一步考虑以骨干电网供能系统特点,研究了线路尾端带负荷合闸对降低过电压的效果。结果表明输电线路尾端带适当的负荷合闸不仅能有效降低空载线路合闸瞬间的暂态过电压和抑制线路末端的工频过电压,空充合闸时通过负荷控制,可使仿真波形更平稳,更有利于消除毛刺现象。

The research of power system restoration is an important subject to ensure the fast, safe and stable restoration of power failure area. Overvoltage verification during power line restoration is the key step to ensure the feasibility of power supply restoration scheme. Aiming at the problem of overvoltage in the process of restoring power supply recovery path, a detailed simulation model is established by using the simulation software MATLAB/Simulink to study the influencing factors of the overvoltage amplitude at the end of the line when the backbone grid restores power supply path. A large number of simulation results show that the length of no-load line and three-phase asynchronous closing and three-phase asynchronous closing of circuit breaker have significant influence on the amplitude of the line tail overvoltage. Based on the simulation results, considering the characteristics of the backbone power supply system, the effect of load closing at the end of the line on reducing overvoltage is studied. The results show that proper load closing at the end of transmission line can not only effectively reduce the transient overvoltage at the closing moment of no-load line and suppress the power frequency overvoltage at the end of line, but also make the simulation waveform more stable and more conducive to eliminating burr phenomenon through load control at the closing time of no-load line.