Adaptive single-phase auto-reclosing method for bundled renewable energy transmission lines based on temporal structural mutation of coupled voltage

The integration of renewable energy (RE) into power system complicates fault nature identification and adaptive single-phase auto-reclosing (ASPAR). This paper analyzes the harmonic output mechanism of RE in high-penetration scenarios in China, and confirms the occurrence of odd-order harmonics during ASPAR. A novel adaptive single-phase auto-reclosing method based on the temporal structural mutation of coupled voltage is proposed. By analyzing the voltage coupling loop, it is found that the temporal structural mutation feature remains unaffected by the harmonics of RE or the configurations of line shunt reactors, which is quantified by the integral root mean square (RMS) value of the fault-phase coupled voltage. Two consecutive sliding windows are used for integral RMS calculation and the adaptive threshold is set to enhance reliability. After arc extinction of transient faults, the integral RMS value exceeds the threshold, while in permanent faults, the value remains below the threshold. The proposed method is validated through PSCAD/EMTDC simulations. It adapts to various fault scenarios, RE penetration levels, and shunt reactor configurations, while demonstrating robustness to noise. By mitigating risks introduced by RE, it enhances the success rate of ASPAR.