Data for: "Characteristics of Impulse-driven Surface Flashover across Polymers with Different Surface Conditions"

This dataset includes raw and processed data for the characterisation of impulsive flashover across solid-gas (laboratory air) interfaces, where the solid materials included PVC (polyvinylchloride), Delrin (polyoxymethylene), Torlon (polamide-imide), Ultem (polyetherimide), and Perspex (polymethymethacrylate). Includes the effects of material, rate-of-rise, and energisation polarity.

Samples were prepared as cylindrical samples of 20 mm diameter and ~10 mm height, with two different surface conditions on the top and bottom flat cross-sectional surfaces: “as-received” and “machined” – the latter treated using a ZCC EMP02-040-A16-AP11-05C shoulder mill. Each cylinder had profilometry data recorded across four evenly-spaced evaluation lengths separated by 90 degrees on the circular surfaces then processed using the motif characterisation method according to the ISO 12085 Geometric Product Specifications (GPS) international standard. Surface profiles were measured using the Accretech Handysurf 35+ manual profilometer for every sample subject to a different set of experimental conditions, along evaluation lengths of 5 mm at 0.6 mm/s.

In total, raw profilometry data includes 5 materials × 4 measurement locations × 2 surface conditions × 2 polarity × 2 rates-of-rise × 2 samples per surface condition = 320 primary profile curves, provided as plaintext .txt files direct from the profilometer using the CNOMO setting.

Surface flashover voltage and current waveforms were collected by inducing electrical breakdown across each sample surface that was embedded within a cylindrical ground electrode. Samples were energised through a needle electrode (soft-tone gramophone needle) of ~80 μm tip radius, placed perpendicular and centred on the circular surface. Each sample was subjected to 20 high-voltage shots using two different rates-of-rise and of both polarities, with 1 m 30 seconds delay between each shot. Nanosecond rise-time impulses (~20 ns) were generated using a stacked-Blumlein generator, and long-rise time (~100 μs) impulses using a Samtech TG-01 trigger generator. High voltage diagnostics for the former included a copper-sulphate divider paired with a NorthStar PVM-5 high-voltage probe, with breakdown current waveforms captures using a Pearson model 6600 current transformer. The latter utilised a Tektronix P6015A probe, and no current waveforms were captured. All waveforms were captured and exported from a Tektronix TDS3054C digital oscilloscope.

In total, raw breakdown data includes 5 materials × 2 polarity × 20 shots × 2 surface condition × 2 samples per surface condition × 2 rates-of-rise = 1600 sets of breakdown voltage and current oscillograms, provided as .csv files. Note that current waveforms are only present for tests involving the Blumlein generator.

This dataset further includes a complete set of processed data, which includes 5 materials × 2 polarity × 2 rate-of-rise × 2 surface condition × 2 samples per surface condition = 80 separate .xml files, one per tested surface. These enclose the averaged surface motif characteristics from the four measurement locations and processed using the ISO 12085 standard. Also included are an additional 80 .xml files containing the impulsive flashover statistics arising from the fitting of 2-parameter Weibull distributions to breakdown voltages and times. Note that breakdown voltages are not reported for the case of the Blumlein due to the inability to induce overstressed breakdown, and only times-to-breakdown are included.