Self-synchronization longitudinal current differential protection method suitable for power transmission line

• Main Authors: GAO HOULEI, HUANG JIAKAI
• Format: Patent
• Language: Chinese; English
• Published: 17.11.2017
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The present invention discloses a self-synchronization longitudinal current differential protection method suitable for a power transmission line. The method includes the following steps that: fault condition detection and fault time point extraction are realized according to the fault features of the line; with the fault time points of two ends of the protected line adopted as time reference, current data are synchronized, and therefore, excellent effects can be realized in the vicinity of a zero crossing point; and according to the influence of the reflection and reflection process of traveling waves, noise interference and the like, seven consecutive sampling points are detected, and it is confirmed that a fault occurs when at least four points change suddenly, and therefore, the reliability of protection and the precision of the time point of the fault are both guaranteed. The method of the invention does not depend on synchronous clocks and does not need to adopt extra equipment; and the method fully uti