基于改进故障点法的电压凹陷评估

针对传统故障点法选取故障点带有盲目性的问题,提出了基于解析式的改进故障点法。算法考虑了电网传输线上的故障分布和故障类型,并根据电压凹陷深度和故障距离的关系曲线对传输线分区,将每个区间作为一个故障点,因此在每条传输线上只要设置较少数量的故障点,通过每个故障点的故障概率分布评估不同电压凹陷深度区间的凹陷频次。并由电压凹陷深度和故障距离的曲线确定不同电压限值的临界点,进而确定电网的凹陷域。提出的改进故障点法用于评估IEEE 30节点标准测试系统的电压凹陷频次,验证了该方法的正确性和实用性。所提方法适用于任何规模电网发生对称故障和不对称故障时的电压凹陷频次评估。

Assessment of voltage sag based on improved fault positions method

An improved fault positions method based on analytical expression is proposed for fault position selection to overcome the blindness of traditional methods.Considering the fault distribution and fault types of transmission lines,it divides the transmission lines according to the relationship curve between the voltage sag depth and fault distance and takes each division as a fault position.Thus fewer fault positions are set and their frequency of voltage sag is assessed by fault probability distribution.It calculates the critical points of different voltage threshold by the relationship curve to determine the vulnerable area.The application to IEEE 30-bus test system validates its correctness and practicality.It works for both symmetric and asymmetric faults of power grid of any size.