故障全量的分相复合阻抗输电线路纵联保护原理

提出了一种基于故障全量的分相复合阻抗输电线路纵联保护原理,它根据线路两端电压、电流故障全量差的比值引入分相阻抗,并以计算得到的阻抗数值判断故障是否发生在区内.在区外故障时,分相阻抗等于线路全长的正序阻抗;在区内故障时,分相阻抗明显偏离上述正序阻抗.该原理为幅值判据,不仅易于整定、具有自选相功能,而且性能可靠、动作灵敏、适应性强,EMTP数字仿真和动模试验结果验证了其有效性.

Transmission Line Pilot Protection Principle of Fault Total Content Based on Composite Impedance of Individual Phase

A transmission line pilot protection principle based on the composite impedance of indi-vidual phase is proposed. The individual phase impedances are calculated from the fault total con-tent differences of the voltages and currents at both terminals of the line, and then used for jud-ging if the fault is occurs at the line. If the fault is outside of the protected area, the individual phase impedances just equal to the positive sequence impedance of whole length of the transmis-sion line, while they will obviously differ from the determined value in case of the fault inside of the protected area, which refers an amplitude criterion. The proposed protection with independent phase selection possesses identity of reliable performance, sensitive operation, and strong adapta-tion. The EMTP simulation and the dynamic simulation test results indicate the effectiveness of the presented principle.