Hold-Off and Nanosecond-Scale Delay Times of C4F7N Electric Breakdown Compared to Other Insulating Gases at Up to 3 Atm Pressure

The presented work expands the tested pressure regime of C4F7N electric high-voltage pulse breakdown to ~3 atmospheres for tens of nanoseconds pulse applications. Previously, the normalized pulsed electric field vs. breakdown delay time was determined for a variety of gases, such as mixtures of C4F7N, SF6, N2, CO2, between 1 atm and 2 atm. It was found that C4F7N mixtures outperformed SF6 mixtures breakdown hold-off in this pressure region. Gas mixtures of C4F7N with 50% CO2 also exhibited increased breakdown fields when compared to 100% SF6 test in the 1 atm to 2 atm regime. These mixtures also displayed an increased time delay-pressure product compared to 100% SF6.