The analysis and discrimination of the element is often performed during production and operation of the coupling capacitor.In this paper

the relationship among capacitance variation rate

increment of tanδ

number of elements n and resistance of the breakdown point of the coupling capacitor in the element breakdown is described by way of setting up the element breakdown model.The conclusions that the maximum variation of capacitance is about k/n

the maximum increment of tanδis no more than k/2n in case of breakdown of element k is obtained.These conclusions are helpful to analyze the parameters variation in the element breakdown

or make discrimination of the breakdown and its severity in accordance with the parameters variation.