基于故障分量的分相阻抗差动保护新原理

Novel Principle Investigation of Segregated Phase Impedance Differential Protection Based on Fault Components

提出了一种基于故障分量的分相阻抗差动保护新原理。该原理分别提取线路两端保护安装处的故障分量进行阻抗计算,然后利用这2个阻抗之差构成阻抗差动判据。该原理无需进行采样数据同步处理,耐受电容电流和过渡电阻的影响。电流幅值差动保护判据以线路两侧的电流幅值差为动作量,幅值和为制动量,在发生电压互感器断线时,可作为阻抗差动保护判据的补充判据。仿真结果验证了该原理的正确性和有效性。

A novel principle of segregated phase impedance differential protection based on the fault components is proposed. The impedance differential criterion is created with the difference between two impedances which are calculated from fault component data at both ends of the line, respectively. By this principle, it is unnecessary to synchronize sampled data, and the influence of capacitive current and fault resistance can be ignored. The current amplitude differential criterion is proposed to supplement the impedance differential criterion. It takes the difference of two current amplitudes calculated at both ends as the operating component, and the sum of these two current amplitudes as the restraint component. The simulation results show the correctness and validity of the principle.