Nonintrusive Anomaly Detection of Users’ Reactive Power Compensators Using Metering Data

Fault detection in users’ reactive power compensators (URPCs) remains a critical challenge, particularly for general commercial and industrial consumers lacking technical expertise. Undetected URPC malfunctions not only increase electricity costs for users but also aggravate utility power losses. To address this issue, we propose a novel remote fault detection framework that exploits the joint distribution of active load levels and power factors derived from metering data. A vision transformer with a large margin-aware focal model is then employed to effectively classify the operational states of URPCs, using joint frequency distribution matrices as characteristic representations. Unlike conventional approaches, the proposed method relies exclusively on metering data, thereby simplifying deployment and enhancing accessibility for nonspecialist users. This enables timely operation and maintenance of URPCs, reducing electricity costs and improving overall power system efficiency. The effectiveness of the proposed approach is validated through extensive simulations.