摘要
对110 kV线路距离保护有关圆阻抗与四边形阻抗相结合的原理在电力系统应用中出现的问题进行了分析和探讨。经实例分析发现,四边形阻抗元件在现场应用中无法整定退出,当本线路保护不需要作为下一级线路变压器远后备保护时,会造成距离Ⅲ段保护范围扩大,当下一级线路变压器中、低压侧发生故障时,可能导致本线路距离Ⅲ段保护超范围动作。针对此问题,提出在保护装置定值项目中增加四边形阻抗元件投退控制字,从而解决保护超范围动作问题,为继电保护装置的安全可靠运行提供运行维护经验,为保护装置的制造、研发提供参考和借鉴。
The paper analyses and discusses the problems existed in the application of combining the circular and quadrilateral impedance for 110 kV line distance protection in power system. The case study found that the quadrilateral impedance element can not be applied in the field setting out. When the line protection does not require as the remote backup protection of the transformer in the next line, the protection range of the distance zone-Ⅲ will be expanding. Thus, when the faults occurs in the middle and low voltage side of the transformer in next line, the distance zone-Ⅲ protection in local line will act beyond protection range. Aiming at this problem, adding the investment return control word of quadrilateral impedance element for the setting project of protection devices is proposed to solve the problem, which provides maintenance experience for safe and reliable operation of the protection devices, and also provides the reference for the R＆D of the protection devices.
出处
《陕西电力》
2011年第8期79-81,89,共4页
Shanxi Electric Power
关键词
距离保护
四边形阻抗
远后备距离
上抛圆阻抗
distance protection
quadrilateral impedance
remote backup distance
up-parabolic circular impedance
