LOAD COMPENSATION IN DISTANCE PROTECTION OF A THREE-PHASE POWER TRANSMISSION LINE

摘要

The present invention relates to a load compensation method for phase-to-ground loops in distance protection, comprising following steps: estimating a first reactive reach (ac) assuming zero fault resistance or with a positive sequence current; estimating a second reactive reach (a0) with a zero sequence current; estimating a third reactive reach (a2) with a negative sequence current; estimating import or export condition; estimating a fourth reactive reach for import (ai) or export (ae) condition based on the first, second and third reactive reach; and estimating a fault impedance based on the estimated fourth reactive reach.