Core Concepts
A novel attention-based convolutional autoencoder (ABCD) framework that effectively detects anomalies in cooling liquid conductivity and identifies potential risks in HVDC systems, enabling informed maintenance decisions.
Abstract
The paper proposes a novel attention-based convolutional autoencoder (ABCD) framework for anomaly detection and risk assessment in HVDC cooling systems. The key highlights are:
The ABCD framework leverages convolutional layers and an attention mechanism to capture intricate patterns and relationships within the complex cooling system data, transforming the high-dimensional data into a lower-dimensional latent space.
The encoder portion of the ABCD maps the original data onto this latent space, while the decoder reconstructs the original data from the latent representations. The attention mechanism helps the model focus on the critical features during training, improving the representation learning.
The anomalies detected by the ABCD model are then evaluated for potential risks using Failure Mode Effect and Criticality Analysis (FMECA). The risk priority rank is calculated based on the severity, probability, and detection probability of the anomalies.
To ensure the reliability and trustworthiness of the model's predictions, a calibration technique is employed to quantify the match between the predicted probabilities and actual observations. The well-calibrated model produces predictions that align closely with real-world outcomes, enhancing confidence in the assessments.
Experiments on real-world HVDC cooling system data demonstrate the effectiveness of the ABCD framework, with a 57.4% increase in performance and a 9.37% reduction in false alarms compared to a convolutional autoencoder without attention.
The risk insights derived from the ABCD framework can help cooling system designers and service personnel make informed decisions about maintenance strategies, optimizing the balance between the costs of resin replacement and the risks of system failures.
Stats
The HVDC station's cooling subsystem data from 2020 to 2023 was used for the study.
The 2021 and 2022 data were used for training, while the 2020 data served as unseen test data.
Quotes
"The anomalies detected by the ABCD model are then evaluated for potential risks using Failure Mode Effect and Criticality Analysis (FMECA). The risk priority rank is calculated based on the severity, probability, and detection probability of the anomalies."
"To ensure the reliability and trustworthiness of the model's predictions, a calibration technique is employed to quantify the match between the predicted probabilities and actual observations. The well-calibrated model produces predictions that align closely with real-world outcomes, enhancing confidence in the assessments."