非全相运行事故的分析及故障处置建议
Analysis of Non-Full-Phase Operation Incidents and Recommendations for Fault Handling
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摘要: 非全相运行作为电力系统中一种典型的异常工况,易引发零序电流增大、中性点电压偏移等问题,对电网安全稳定运行构成显著威胁。本文结合某220kV变电站母线倒闸操作中线路非全相故障的实际案例,系统梳理了故障发生、告警上报、现场检查与调度处置的全过程;并结合母联断路器非全相运行的等效模型,对纵向故障下的零序网络特性进行了理论分析。研究结果表明,非全相运行产生的零序电流分布受中性点接地方式、网络结构及负荷水平共同影响,处置不当易导致保护误动。最后,本文分别针对线路/主变断路器和母联断路器非全相故障,提出了层次清晰、操作性强的调度处置流程与注意事项,旨在为现场运行与调度指挥提供参考,提升电网应对非全相故障的安全控制能力。Abstract: Non-full-phase operation, as a typical abnormal condition in power systems, can easily lead to increased zero-sequence currents and neutral point voltage shifts, posing a significant threat to the safe and stable operation of the power grid. This paper systematically reviews the entire process—from fault occurrence and alarm reporting to on-site inspection and dispatch handling—based on an actual case of a line non-full-phase fault during bus switching operations at a 220kV substation. It also conducts a theoretical analysis of zero-sequence network characteristics under longitudinal faults using an equivalent model of non-full-phase operation for bus tie circuit breakers. Research findings indicate that the distribution of zero-sequence currents generated by non-full-phase operation is jointly influenced by neutral grounding methods, network structure, and load levels. Improper handling may easily lead to protection misoperation. Finally, this paper proposes clear, operationally feasible dispatch handling procedures and precautions for non-full-phase faults in line/main transformer circuit breakers and bus tie circuit breakers, respectively. These aim to provide reference for on-site operation and dispatch command, enhancing the grid''s safety control capabilities in responding to non-full-phase faults.
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