Transient selectivity for enhancing autonomous fault management in unearthed distribution networks with DFIG-based distributed generations

- The transient directionality is incorporated in the autonomous control to enhance the fault management in the distribution networks.
- This directional transient selectivity mainly depends on the waveform chopping features extracted from the front slope of the fault currents.
- The proposed approach is evaluated for both earth and phase faults in unearthed distribution networks with distributed generations.

This paper proposes a method for identifying the faulty section in unearthed distribution networks connected with Doubly-Fed Induction Generator (DFIG)-based distributed generation. The proposed method depends on a dedicated transient-based selectivity function that is incorporated in an autonomous fault management procedure. Faulty section discrimination is performed by extracting the relative polarities of the front slopes at the terminals of each section generated by the fault current. The integration procedure of the protection selectivity function with the autonomous control is designed for the unearthed MV networks. Both earth and phase faults are considered in order to realize a broad, versatile and practical classification for such networks. Simulation cases are prepared using the ATP-EMTP package for testing purposes. The results corroborate the efficacy of the proposed method for classifying the faulty segment in distribution networks even for high impedance arcing faults as well as with considerable amounts of distributed wind turbines.