Numerical simulation method for three-dimensional dynamic evolution process of streamer discharge of insulating oil

Abstract

The invention discloses a numerical simulation method for the three-dimensional dynamic evolution process of streamer discharge of insulating oil. The method comprises the steps of firstly, establishing an insulating oil discharge model and an electrohydrodynamics model describing the physical process of discharge of the insulating oil; then, determining physical quantity parameters in a governing equation, setting physical disturbance points, determining boundary conditions and carrying out mesh division on a solution domain and a boundary; carrying out numerical solution and postprocessing on the governing equation through finite element software to obtain the spatial-temporal evolution dynamic state of the electric field intensity, the particle concentration distribution characteristics and discharge channel furcation behavior in streamer discharge. According to the method, the electric field intensity and charged particle concentration distribution in discharge of the insulating oil can be directly estimated, the influence of the space charge effect in the discharge channel forming process can be quantitatively evaluated, the discharge furcation behavior caused by stochastic disturbance can be simulated, and therefore important data support and theoretical bases can be provided for research on the harmfulness of discharge of liquid dielectrics.

Description

【Technical field】 [0001] The invention belongs to the field of liquid dielectric discharge under high electric field, and specifically relates to a numerical simulation method for the three-dimensional dynamic evolution process of streamer discharge in insulating oil. Numerical simulation of dynamic and charge distribution properties. 【Background technique】 [0002] As an excellent engineering liquid dielectric, insulating oil is widely used in large-scale power equipment and pulse power devices, and the electrical insulation and discharge problems under high electric fields are one of the bottlenecks that limit the overall performance and reliability of such equipment. Breakdown in liquid dielectrics is generally considered a form of streamer discharge, meaning all forms of conductive channel formation, such as diffuse and dendritic discharges. The streamer discharge electrode is easy to develop into a flashover or direct breakdown event along the surface, directly destroy...

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Problems solved by technology

However, two-dimensional simulation cannot describe the bifurcation behavior and tree structure of liquid dielectric discharge caused by external physical random disturbances, such as changes in the local density of the dielectric and changes in the local dielectric constant. It is urgent to carry out research on full three-dimensional discharge simulation in insulating oil. This is not only conducive to comprehensively revealing the microscopic dynamic evolution characteristics of liquid dielectric discharge and the bifurcation behavior mechanism of discharge channels, but also provides strong data support for the evaluation of discharge hazards in liquid dielectrics, which has important theoretical value and practical significance

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