Research on Flashover Characteristics and Charge Evolution Mechanism of Silicone Rubber Under Different Temperature and Pressure

The interface between gas and insulation dielectric is one of the weakest links in the insulation of electrical equipment. This paper focuses on the influence of temperature and pressure on the surface flashover of silicone rubber under the action of AC electric field was studied by combining simulation and experiment, and the influence mechanism of temperature and pressure on the surface flashover was revealed. The experimental results show that the flashover voltage decreases from 12.24 kV to 9.43 kV when the temperature increases from −40 °C to 60 °C. Meanwhile, the pressure decreases from 1 atm to 0.5 atm, and the flashover voltage decreases from 10.24 kV to 6.43 kV. At the same time, the lower temperature weakens the ionization process, resulting in less electron accumulation. The simulation results show that the electron density of the material surface decreases from 1.41 × 10¹⁹ m⁻³ to 8.46 × 10¹⁸ m⁻³. As the pressure decreases, the impact-ionization process is enhanced, resulting in increased electron accumulation. The electron density of the material surface increases from 2.25 × 10¹⁹ m⁻³ to 6.59 × 10¹⁹ m⁻³. This work has important guiding significance for studying the influence mechanism of different environments on flashover.