Flowchart of ELM-based rule extraction.

<p>Flowchart of ELM-based rule extraction.</p

Test results in Case-1.

<p>Test results in Case-1.</p

Influence of the pheromone evaporation rate on accuracy (with 400 ants).

<p>Influence of the pheromone evaporation rate on accuracy (with 400 ants).</p

Transient stable case.

<p>Transient stable case.</p

The ROC curve in Case-1.

<p>The ROC curve in Case-1.</p

Transient unstable case.

<p>Transient unstable case.</p

The input features for the southern power system of Hebei province.

<p>The input features for the southern power system of Hebei province.</p

Areas under the receiver operating characteristic curve (AUC) value of test data and training data based on 10-fold cross validation ascending in order by AUC value.

<p>X-axis label 1–10 represents the model code. The mean test AUC value is 0.93 and the mean training AUC value is 0.95.</p

The input features for the New England 39-bus test system.

<p>The input features for the New England 39-bus test system.</p

Test results in Case-2.

<p>Test results in Case-2.</p