A reliable approach to eliminate distributed capacitive current of transmission lines

Transmission lines with high voltage generate a distributive capacitive current which have negative impact on differential current protection during faulty conditions. In order to remove the harmful and negative effects of distributed capacitive current on differential current protection, a novel scheme based on Bergeron's model is proposed in this article. Differential criterion is built with the same amount of currents that is computed from both ends to the set point. Implementation of the differential current protection under low sampling frequency proved that the criterion is correct for practical execution. The calculation of distributed current at the set point has been achieved using a unique procedure of cubic spline data interpolation point at each sampling interval under low sampling frequency. PSCAD simulation results in frequency domain show that this novel scheme for differential current protection is not affected by harmful effects of distributed capacitive current as compared to traditional differential current protection. Moreover, novel scheme has certain advantages such as high sensitivity, fast action speed and high reliability.