Anti-Fault Resistance Protection of AC Outgoing Transmission Lines Emanating from Inverter-interfaced Renewable Energy Power Plants

The existence of fault resistance can significantly weaken the fault characteristics of AC outgoing transmission lines emanating from inverter-interfaced renewable energy power plants. To solve the problems caused by different types of the faults through fault resistance (FTFR, the faults that the fault point resistance is greater than zero) in AC outgoing transmission lines, a novel anti-fault resistance protection principle based on the energy consumption of fault resistance is proposed in this paper as the backup protection of FTFR. The theoretical analysis show that this protection principle can identify different types of internal FTFR in AC outgoing transmission lines effectively, it can also isolate the FTFR with high reliability and high sensitivity by adopting self-adaptive threshold, and is not affected by the factors such as the fault position, the fault resistance value, and etc. Finally, a model is established in PSCAD/EMTDC to verify the validity of the protection principle.