基于故障分量综合阻抗的输电线路纵联保护

提出了一种基于故障分量综合阻抗的纵联线路保护新原理。利用故障时线路两端故障分量电压相量和与故障分量电流相量和的比值，来判断线路上是否发生了故障。在外部故障时，该比值反映输电线路上的容抗，其模值较大；内部故障时，该比值反映系统电源阻抗和线路阻抗，其模值相对较小，据此可以区分线路上的内部和外部故障。新原理易整定，本身具有选相能力，不受电容电流的影响，可以用于带或不带电抗器补偿的线路，理论上与过渡电阻无关。EMTP仿真和动模数据验证了该原理的有效性。

A Novel Transmission Line Pilot Protection Based on Fault Component Integrated Impedance

Based on the ratio between the sum of two terminals fault component voltage phasor of the transmission line and the sum of two terminals current phasor of the same line, which is defined as fault component integrated impedance, a new transmission line pilot protection principle is proposed. When an outer fault occur, the fault component integrated impedance reflect the capacitance impedance of the line, its value is large, and when an internal fault occur, the fault component integrated impedance reflect the impedance of the system source and the line, its value is relative small. According to such a characteristic, whether there is fault in the line can be distinguished. The criterion is not influenced by the capacitive current and fault resistance, and can be applied in the line with or without shunt reactor. Also, it can be easily set. Simulation with EMTP and dynamic model data shows that the presented principle has high sensitivity and reliability.