Lightweight Monitoring Method of Transient Power Quality Disturbances Based on Phase-Robust Kurtosis

Transient power quality disturbances (PQDs) are highly abrupt and destructive, therefore their reliable monitoring is essential for secure and stable power system operation. A wide variety of monitoring indices and the full-data upload architecture pose increasing challenges for lightweight monitoring of transient PQDs. High-order statistics (HOSs), especially kurtosis, can effectively capture abrupt waveform changes, making them suitable as unified monitoring indices of multi-type transient PQDs. However, traditional kurtosis has reduced monitoring accuracy due to its phase sensitivity. To address this issue, a lightweight monitoring method for transient PQDs based on a phase-robust kurtosis (PRK) index is proposed. This method first introduces kurtosis as a lightweight monitoring index and explains the cause of phase sensitivity from both theory and waveform distribution characteristics. Then, a PRK index is proposed based on phase-aligned coupling component to eliminate the phase sensitivity and accurately characterize the severity of transient PQDs. In addition, a cloud-edge-end collaborate lightweight monitoring method is developed to clarify the monitoring process of PRK index, which effectively guides the lightweight acquisition and transmission of monitoring data and supports intelligent analysis. Both simulation and actual measured data demonstrate the significant capability of the proposed method to reduce data volume and improve monitoring accuracy.