Multi-Module Based CVAE to Predict HVCM Faults in the SNS Accelerator

Abstract

We present a multi-module framework based on Conditional Variational Autoencoder (CVAE) to detect anomalies in the power signals coming from multiple High Voltage Converter Modulators (HVCMs).We condition the model with  the specific modulator type to capture different representations of the $normal$ waveforms and to improve the sensitivity of the model to identify a specific type of fault when we have limited samples for a given module type. We studied several neural network (NN) architectures for our CVAE model and evaluated the model performance by looking at their loss landscape for stability and generalization. Our results for the Spallation Neutron Source (SNS) experimental data show that the trained model generalizes well to detecting multiple fault types for several HVCM module types.The results of this study can be used to improve the HVCM reliability and overall SNS uptime.

Keywords: Anomaly detection, Particle Accelerators, Variational Autoencoder, Spallation Neutron Source, High Voltage Converter Modulator