In practical data-driven applications on electrical equipment fault diagnosis, training data can be poisoned by sensor failures, which can severely degrade the performance of machine learning (ML) models. However, once the ML model has been trained, removing the influence of such harmful data is challenging, as full retraining is both computationally intensive and time-consuming. To address this challenge, this paper proposes a SISA (Sharded, Isolated, Sliced, and Aggregated)-based machine unlearning (MU) framework for power transformer inter-turn short-circuit fault (ITSCF) localization. The SISA method partitions the training data into shards and slices, ensuring that the influence of each data point is isolated within specific constituent models through independent training. When poisoned data are detected, only the affected shards are retrained, avoiding retraining the entire model from scratch. Experiments on simulated ITSCF conditions demonstrate that the proposed framework achieves almost identical diagnostic accuracy to full retraining, while reducing retraining time significantly.
Figures & tables
Fig. 1: The SISA framework for power transformer ITSCF localization.
Fig. 2: Training accuracy and time on different numbers of shards, i.e., S . If S=1 , it is a non-SISA model, and the training process removing poisoned data is full retraining.
Fig. 3: Comparison of confusion matrices for four cases under 1 ITSCF condition with poisoned data caused by sensor failures.
Fig. 4: Comparison of confusion matrices for four cases under 6 ITSCF conditions with poisoned data caused by sensor failures.
Machine unlearning removes the influence of selected data or concepts from trained models while preserving useful behavior and avoiding full retraining.
Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg · Institute of Electrical Energy Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg