Power Interpretable Causal ODE Networks: A Unified Model for Explainable Anomaly Detection and Root Cause Analysis in Power Systems

TL;DR

This paper introduces PICODE networks, a causality-informed model for power systems that detects anomalies and provides explanations, including root cause localization and anomaly classification, with competitive accuracy and enhanced interpretability.

Contribution

The paper presents a novel causality-based ODE network that jointly detects anomalies and explains their causes, improving interpretability over existing black-box models.

Findings

Achieves competitive anomaly detection performance.

Provides interpretable explanations for detected anomalies.

Reduces dependence on labeled data and external causal graphs.

Abstract

Anomaly detection and root cause analysis (RCA) are critical for ensuring the safety and resilience of cyber-physical systems such as power grids. However, existing machine learning models for time series anomaly detection often operate as black boxes, offering only binary outputs without any explanation, such as identifying anomaly type and origin. To address this challenge, we propose Power Interpretable Causality Ordinary Differential Equation (PICODE) Networks, a unified, causality-informed architecture that jointly performs anomaly detection along with the explanation why it is detected as an anomaly, including root cause localization, anomaly type classification, and anomaly shape characterization. Experimental results in power systems demonstrate that PICODE achieves competitive detection performance while offering improved interpretability and reduced reliance on labeled data or external causal graphs. We provide theoretical results demonstrating the alignment between the shape of anomaly functions and the changes in the weights of the extracted causal graphs.