Compensation of incorrect measurement results as a result of conduction unbalance during distance calculation after short-circuit tripping

Conventional distance protection relays face the challenge of accurately calculating fault distances for unbalanced or non-transposed lines. The unbalance of the lines results in significant deviations during distance calculation. Previous studies have presented methods that compensate these deviations, for example by compensating for coupling effects. Often, these methods require complex relay configurations or need information from multiple measurement points. This paper, in contrast, introduces a new algorithm that calculates the measurement deviations for all fault loops in a conductor-selective way without the use of additional measurements. This method is universally applicable to different line and tower constructions, including non-transposed and special-transposed lines. The method works in the natural system and includes capacitive coupling effects, allowing for accurate correction of distance calculation results after short circuit tripping. Experimental results have validated that the proposed method reduces the deviations significantly and increases the accuracy of fault localization.