POWER TRANSMISSION LINE DISTANCE PROTECTION CURRENT TRANSFORMER SATURATION IDENTIFICATION METHOD AND SYSTEM

摘要

Disclosed are a power transmission line distance protection current transformer saturation identification method and system. According to the present invention, a distance protection locking criterion and a distance protection opening criterion are constructed on the basis of an incomplete differential locking criterion, an incomplete differential opening criterion, a working voltage locking criterion, a working voltage opening criterion, and a current harmonic unlocking criterion, thereby ensuring that, in case of a reverse direction fault and current transformer saturation in a half-switch wiring or annular wiring mode, distance protection is still reliable and free of maloperation, and ensuring that, in case of a forward direction fault and various reverse direction to forward direction faults, distance protection can still operate reliably.