距离Ⅲ段保护特性研究与整定计算

Distance Section Protection Characteristic Research and Setting Calculation

当110 k V线路电源侧距离保护作为YND11型变压器低压侧故障远后备时,整定阻抗不能简单地取线路阻抗与变压器阻抗之和,针对圆特性、多边形特性及圆、四边形组合特性构成的相间距离Ⅲ段保护在作为变压器远后备和躲负荷能力方面进行了深入研究,并总结出各特性构成的相间距离Ⅲ段保护在负荷阻抗角不同的情况下,计算躲负荷可靠系数的方法,该方法应用于实际工作,使计算距离保护动作特性躲负荷可靠系数变得简单,取得了良好的效果。

When 110 kV line distance relay serves as remote backup as YND11 type transformer fault on transformer low side backup, setting impedance is not simply the sum of line impedance and transformer impedance. The capability of distance relay on transformer remote backup and load conservation are analyzed in detail for relays of circular, polygon and circular-quadrilateral combined characteristics. The load conservation coefficient calculation method is summarized for different types of distance relays under different load impedance angles. The field test results show the simplicity and validity of proposed calculation method.