Switching Impulse Breakdown Characteristics of Environmental-Friendly Insulation Material C₅F₁₀O Under Highly Non-Uniform Field

C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O is a promising eco-friendly alternative material to SF6 for insulation in electrical equipment. Its behavior under operational impulse voltage is key for insulation design. This research delves into how gas pressure, the species of buffer gas, and their mixing proportions affect the impulse voltage endurance of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O mixtures used as an insulating medium. The findings indicate that in highly non-uniform electric fields, the C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O blend exhibits a notable polarity-dependent behavior under operational impulse voltage conditions. Specifically, the 50% breakdown voltage (U<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50%</inf>) in the negative polarity rises linearly with an increase in gas pressure. Conversely, the U<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50</inf>% in the positive polarity shows a “hump” pattern as gas pressure varies, which is linked to the electric field distortion caused by space charge. At low mixing ratios, the insulating strength of the mixed gases significantly improves with an increase in C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O content and tends to saturate at high mixing ratios. The study further confirms that by increasing gas pressure or the content of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O, the operational impulse withstand performance of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf>O mixed gas in highly non-uniform electric fields can be effectively enhanced, giving it the potential to replace SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> under application conditions.