A Hybrid Transient Voltage-Based Fast Auto-Reclosing Scheme for Renewable Energy Outgoing Lines

Considering the widespread utilization of conventional auto-reclosing strategies in renewable energy outgoing lines, the inability to distinguish fault characteristics before reclosing poses risks to the safe operation of renewable energy systems, particularly in cases of permanent faults causing severe secondary impacts. Therefore, a fast adaptive auto-reclosing scheme for renewable energy outgoing lines based on transient voltage without shunt reactors on 220kV is proposed. Firstly, the equivalent circuit models for transient and permanent faulty phase voltages are established, expressions for faulty phase voltages are derived. Secondly, Fast Fourier Transform (FFT) analysis methods are employed to extract data features from each simulated fault and faulty phase fundamental frequency voltage under different fault characteristics is investigated. Finally, a fast adaptive auto-reclosing scheme based on fundamental frequency voltage amplitude is proposed. Theoretical derivations and real-time simulations on the RTDS platform confirmed that the proposed adaptive reclosing scheme can prevent system overvoltage, achieve fault location even in the case of permanent faults, and provide immunity to fault resistance up to 100Ω.