A surface discharge non-equilibrium plasma model of air–polyimide under pulsed electrical stress is established, by considering the reaction of charged particles on the dielectric surface and the secondary electron emission caused by the condition that high-energy particles bombard the material surface. The model defines the chemical reaction of air discharge by using simplified set of reactions, which greatly reduces the complexity of the model. To avoid the negative value of particle density in the process of solution, the logarithmic finite-element method is used to solve the model established, so as to implement the dynamic simulation of the surface discharge process. Also, the temporal and spatial evolution of the microparameters such as charge and electric field distribution during discharge are obtained, and the reliability of the model is verified by experiments in terms of discharge development pattern and surface charge accumulation. By comparing the development process of surface discharge under single pulse and repetitive pulses, it can be seen that surface discharge develops from needle electrode to ground electrode under both repetitive pulses and single pulse stress, but the relationship between the discharge propagation time under repetitive pulses and pulse repetition rate is a ‘u’ curve, and the inflection point moves to higher repetition rate region with the increase of voltage.

中文翻译：

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脉冲电应力下大气压下空气中聚酰亚胺绝缘表面放电的有限元分析

通过考虑电介质表面上的带电粒子与高能粒子轰击材料表面的条件引起的二次电子发射之间的反应，建立了空气-聚酰亚胺在脉冲电应力下的表面放电非平衡等离子体模型。该模型使用简化的反应集定义了空气排放的化学反应，这大大降低了模型的复杂性。为避免在求解过程中出现颗粒密度的负值，采用对数有限元方法对所建立的模型进行求解，从而实现了表面放电过程的动力学模拟。此外，还可以获得诸如放电过程中的电荷和电场分布之类的微观参数的时空演化，并通过实验验证了模型的可靠性。通过比较单脉冲和重复脉冲下表面放电的发展过程，可以看出，在重复脉冲和单脉冲应力下，表面放电都从针状电极向接地电极发展，但是重复脉冲和放电条件下放电传播时间与放电时间之间的关系。脉冲重复率是一个“ u”曲线，拐点随着电压的增加而移到较高的重复率区域。