Differential protection of inter-system transmission lines with charge capacity compensation

Energetics. Electrical engineering

The goal of the article was to investigate the dynamic properties of longitudinal differential protection of power lines with charge capacity compensation and to develop recommendations for increasing the sensitivity of protection. As a result of the study, it was established that the minimum tripping current of the protection is inadmissible for providing selective operation due to the condition of sensitivity in idle switching modes of the OL. Therefore, an increase in the main braking signal is necessary in order to achieve the required sensitivity and speed. The article presents the results of an evaluation of the effectiveness of the methods proposed earlier in [1] for improving the efficiency of protection. The use of additional braking due to compensation of unbalance currents caused by distributed capacitance of the OL allows to significantly increase the sensitivity of protection.