Systems and methods for propagating brush discharge testing

A system for performing a propagating brush discharge test, the system comprising:

• a grounded layer;
• a dielectric layer that has a first surface and is backed by the grounded layer opposite the first surface of the dielectric layer;
• an initiation electrode with a conductive element that has a body and an exposed tip, wherein the exposed tip is adjacent to the first surface of the dielectric layer such that a voltage differential between the exposed tip and the first surface of less than 50 kV is sufficient to cause an electrical contact between the exposed tip and the first surface, wherein the body of the conductive element is electrically isolated from the dielectric layer, wherein the initiation electrode includes an insulating sheath along the body of the conductive element, wherein the insulating sheath is spaced apart from the first surface of the dielectric layer;
• a high-voltage switch connected to the initiation electrode and configured to selectively isolate the conductive element of the initiation electrode from ground potential;
• a flammable gas in contact with the first surface of the dielectric layer;
• an optical sensor positioned and configured to detect light generated by ignition of the flammable gas due to a propagating brush discharge centered at the exposed tip of the initiation electrode;
• and
• a controller programmed to operate the high-voltage switch to electrically ground the initiation electrode and to operate the optical sensor to collect light.

A method for performing a propagating brush discharge test on a dielectric layer, the method comprising:

• positioning an exposed tip of an initiation electrode adjacent to a first surface of the dielectric layer, wherein the dielectric layer is backed by a grounded layer opposite the first surface of the dielectric layer;
• after positioning, electrically charging the first surface of the dielectric layer to a voltage with a magnitude of at least 4 kV relative to ground potential, while the grounded layer is at ground potential and the initiation electrode is isolated from ground potential;
• and
• after electrically charging, electrically connecting the initiation electrode to ground potential so that the exposed tip of the initiation electrode neutralizes charge on the first surface of the dielectric layer.