基于工频故障分量的自适应接地距离保护

用工频故障分量推导单相接地模型线路经过渡电阻接地时的附加阻抗，用来修正距离保护的测量阻抗，并根据送电侧和受电侧的不同情况决定是否补偿．该方法能准确计算出线路故障阻抗的电阻分量和电抗分量。使四边形特性距离保护的电阻线和电抗线易于整定，避免下倾的电抗线缩小保护的范围和电阻线的躲负荷性能的复杂分析，从而解决保护的拒动和超越问题．算例验证这种距离保护有令人满意的性能，提高了保护的可靠性和灵敏度．

An Adaptive Algorithm of Ground Distance Protection based on Power Frequency Fault Components

Based on the single-phase earthed model, this paper calculates the additional impedance caused by transition resistance, and revises the measurement impedance of distance protection. Compensation is provided depending on different conditions of the sending and receiving ends. This approach can be used to accurately measure the resistance component and reactance component of fault line impedance, which makes the resistance line and the reactance line of quadrilateral characteristic distance relay easier to set. In this case, it can save the reduction in the protection areas due to declining reactance lines amt avoid complex analysis of resistance line dodging load performance. Thereby overreaching and under-reach problems of distance relay can be solved. The numerical examples prove that this distance protection has perfect performances and the reliability and sensibility are thus improved.