电压互感器零序电压回路典型故障的分析与研究

Analysis and Research on Typical Faults of Zero Sequence Voltage Circuit of Voltage Transformers

电力系统运行中电压互感器的零序电压回路易造成继电保护拒动或误动,甚至引发严重电力事故,监视和安全保障措施仍需完善。针对这一问题,文章通过分析研究零序电压回路的接地故障、铁磁谐振影响、电压互感器极性接线错误和断线的现象,并经现场多次实践,结合工程实际采用提高元器件额定电压、加装专用的消谐器、增加零序电压回路的阻尼、采用零序电压滤过器等改进方法和措施,有效消除事故隐患,以期电力系统更安全更可靠运行。

In the operation of power system, the zero sequence voltage circuit of voltage transformers can easily cause the refusal or malfunction of relay protection, and sometimes serious accidents. Surveillance and security safeguards still need to be refined.In response to the problem, this paper analyzes and studies the ground fault of the zero sequence voltage circuit, the influence of ferromagnetic resonance, the wrong polarity wiring and disconnection of voltage transformers. After many field practices, improved methods and measures, such as increasing the rated voltage of components, installing special harmonic eliminators, increasing the damping of the zero sequence voltage loop, and adopting zero sequence voltage filters, are adopted to effectively eliminate hidden dangers of accidents, so that power system will operate more securely and reliably.