An algorithm for sensitive directional transverse differential protection with no voltage inputs

• A new algorithm based on phase-change of double-line currents is proposed for radial networks.
• The algorithm improves sensitivity of Transverse Differential Protection in the case of low consumption.
• By usage of current register locking technique protection sensitivity is enabled in the case of fault from open circuit regime.
• Algorithm's features are tested in several specific cases, such as close-in faults, high-resistance faults, cross-country faults, etc.

Transverse differential protection of double lines in double-fed networks has been discussed by many papers. This paper investigates algorithms based on current increments for directional transverse differential protection with no voltage inputs in radial networks. Weak points of the algorithms are identified and discussed. A new algorithm based on phase-change of double-line currents with improved sensitivity is proposed. For testing purposes, three-phase power system model has been created. On the basis of detailed simulation tests, advantages of the new algorithm are presented. In order to ensure protection sensitivity even in the cases of faults from open circuit regime, current register locking technique has been developed and used in combination with new algorithm.