Three-Phase Adaptive Reclosing Scheme for AC Outgoing Lines of Renewable Energy Stations Based on Active Injection from Energy Storage System

For the problem of blind auto-reclosing onto permanent faults causing secondary impacts on the AC grids of renewable energy sending ends, a fault nature discrimination method for outgoing lines of renewable energy stations based on active injection from energy storage system (ESS) is proposed in this paper. The voltage characteristics of outgoing lines under active injection from grid-forming ESS are investigated, and a fault criterion is proposed based on the difference in voltage characteristics at the sending end of the line between permanent faults and healthy condition. On this basis, a three-phase adaptive reclosing scheme is proposed. The theoretical derivation and simulation results based on the PSCAD/EMTDC platform prove that the scheme can reliably discriminate between permanent faults and transient faults, and can achieve smooth reconnection of renewable energy stations to the grid through voltage/phase pre-synchronous control when the fault disappears, ensuring the prompt restoration of power export from the renewable energy stations. This scheme only requires single-end line information to discriminate the fault nature. It has a strong ability to adapt to transition resistance changes and is unaffected by the fault locations.