Propagating brush discharge testing systems include an initiation electrode, a high-voltage switch, a sensor, and a controller. The initiation electrode has an exposed tip positioned adjacent to a surface of a test article. The high-voltage switch is configured to selectively isolate the initiation electrode from ground potential. The sensor is positioned and configured to detect a propagating brush discharge between the initiation electrode and the test article. The controller is programmed to operate the high-voltage switch to ground the initiation electrode.