I want you to summarise the following words and explain it to me as points The s

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I want you to summarise the following words and explain it to me as points

The streamer criterion is a well-known explanation of the flashover mechanism [6, 8]. Some methods have been derived from it to calculate the flashover in non-uniform electrode air gaps [9, 10]. Larry Warne et al [10] proposed an approach that uses an ionization coefficient for the modeling of breakdown of non-uniform electrode geometries. This offers a good procedure for calculating the breakdown of air gaps.

The application of this method to glass insulators raises the problem of the influence of the dielectric surface onto the flashover process. A surface flashover implies that electrons will collide with the surface generating secondary electrons or sticking into it. Due to the inert nature of glass these phenomena can be neglected if a bigger error is tolerated.

Although the method cannot provide a very accurate estimation of the flashover voltage of glass insulators in power frequency, it allows the analysis of the influence of parameters as arcing distance, electrodes shape or glass thickness.

The procedure is based on the integration of the first Townsend coefficient through the path of the discharge. To calculate the integral, it is necessary to solve first the voltage distribution of the system (geometry, permittivity and conductivity of the materials must be known, as well as the voltage between electrodes).

Explanation / Answer

A streamer discharge is a transient discharge. Streamer discharges can form when an insulating medium like air is exposed to a large potential difference. When the electric field created by the applied voltage is sufficiently large, accelerated electrons strike air molecules with enough energy to knock other electrons off them, ionizing them, and the freed electrons go on to strike more molecules in a chain reaction. These electron avalanches (Townsend discharges) create ionized, electrically conductive regions in the air near the electrode creating the electric field. The space charge created by the electron avalanches gives rise to an additional electric field. This field can enhance the growth of new avalanches in a particular direction. It cause the breakdown of air gap. Then the ionized region grows quickly in that direction, forming a finger-like discharge called a streamer. So that flashover produced in the medium.

There are some methods availabe to calculate the flashover in non uniform electrode. Larry warne proposed a methode to calculate the break down of the air gap between the non uniform electrode . He uses ionization coefficient for this method. There is a problem using this method in case of glass. Because there is surface flashover in case of glass. The electron collinding on the glass produces seconday electron or they sticks to it. For this reason this method can't give a aacurate estimation of the flashover voltage. But it gives analysis of arcing distance, electrode shape , and the thickness of glass.

In this procedure the integration of the first townsend coefficient is done through the path of discharge .

The first townsend coefficient is used where secondary ionization occurs. So in ordet to calculate the integral of townsends first coefficient the voltage distribution shoud be known . This voltage distribution depends upon the geometry, permittivity and conductivity of the matrrial and the voltage between the electrode.  

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