Detecting and interpreting faults in vulnerable power grids with machine learning

TL;DR

This paper uses machine learning to predict and interpret faults in a Norwegian Arctic power grid, providing insights into causes and enabling better prevention strategies.

Contribution

It introduces a methodology combining classifiers and Integrated Gradients for fault prediction and interpretation in power grids, with a focus on local explanations for individual faults.

Findings

Both linear and non-linear classifiers perform well in fault prediction.

Power-quality and weather variables are effective in explaining disturbances.

Integrated Gradients provide detailed, fault-specific insights for system operators.

Abstract

Unscheduled power disturbances cause severe consequences both for customers and grid operators. To defend against such events, it is necessary to identify the causes of interruptions in the power distribution network. In this work, we focus on the power grid of a Norwegian community in the Arctic that experiences several faults whose sources are unknown. First, we construct a data set consisting of relevant meteorological data and information about the current power quality logged by power-quality meters. Then, we adopt machine-learning techniques to predict the occurrence of faults. Experimental results show that both linear and non-linear classifiers achieve good classification performance. This indicates that the considered power-quality and weather variables explain well the power disturbances. Interpreting the decision process of the classifiers provides valuable insights to understand the main causes of disturbances. Traditional features selection methods can only indicate which are the variables that, on average, mostly explain the fault occurrences in the dataset. Besides providing such a global interpretation, it is also important to identify the specific set of variables that explain each individual fault. To address this challenge, we adopt a recent technique to interpret the decision process of a deep learning model, called Integrated Gradients. The proposed approach allows to gain detailed insights on the occurrence of a specific fault, which are valuable for the distribution system operators to implement strategies to prevent and mitigate power disturbances.