Single-Ended Remote Backup Protection Based on Fault Distance Factor of Traveling Wavefront

Zone III distance protection has long operating time and its sensitivity decreases significantly in renewable energy scenarios. In this paper, novel single-ended remote backup protection is proposed based on fault location information contained in traveling wavefront. Firstly, it is demonstrated that the fault distance factor of traveling wavefront is effective in reflecting location of fault in both radial and meshed topologies. Then fault distance-operating time inverse-time characteristic is designed based on fault distance factor, realizing spontaneous sequencing of operating time between the relays at higher and lower zones. This inverse-time characteristic is only determined by location of fault and not influenced by operation mode, control strategy, fault type, fault resistance, etc. A robust algorithm is proposed to efficiently extract the fault distance factor, ensuring protection reliability. Resetting criterions are designed to re-check the existence of fault, avoiding leapfrog tripping and maloperation confronting disturbances. The setting of proposed protection is simple, without the need to update the threshold value according to the system status. Verifications have demonstrated that the proposed protection can be self-adaptive to flexible operation mode of renewable energy transmission system and different topologies. The proposed method also demonstrates high tolerance to fault resistance and noise while maintaining fast operating speed.