Insulating Synergy of Two-Component Gas Mixtures Under Conditions of Fast and Ultrafast Voltage Loading

The study investigates the impulse breakdown voltage values of two-component mixtures of SF₆ gas with N₂, He, and CF₄ gases. These types of mixtures are chosen because they are commonly used in engineering practice, all with the aim of reducing SF₆ gas emissions into the atmosphere (SF₆ gas is considered one of the main contributors to the greenhouse effect). The tests are conducted using impulse voltages of three types: 1) switching impulse (250/2500 μs), 2) lightning impulse (1.2/50 μs), and 3) ultra-fast impulse voltages attributed to nuclear explosions in the atmosphere (1/1000 ns). The applied impulses are selected because such impulse types occur in industrial practice. Naturally, the ultra-fast impulse (1/1000 ns) is not used in engineering practice, but its occurrence would be a precursor to catastrophic consequences. The measured parameter is the percentage composition of components in the two-component mixtures. Measurements are performed under well-controlled laboratory conditions with a combined measurement uncertainty of up to 5%.