Estudo de modelos para definição de um critério de início de corona através da análise de experimentos e simulações computacionais

Abstract

Corona is a phenomenon that may lead to a series of undesirable consequences to power systems. The degradation of surfaces, such as those of polymer insulators, is one of the main concerns. The presence of corona in an arrangment is associated with highlevels of electric field. However, there is no clear understanding on the exact value of the field that leads to corona. This work aims to study the models, proposed in the literature, for corona prediction. Empirical formulations, such as Peeks formula and Schwaigers non-uniformity factor are discussed, their applicability is investigated, and a modified model is proposed. Additionally, the work aims to stimulate the search for models that can be used in practical arrangments, such as the surface of polymer insulators under operational conditions. The proposed model is tested computationally and experimentally. The results show good agreement with experiments, indicating the efficiency of the model to estimate the corona onset voltage. Additionally, the statistical nature of corona is taken into account, so that to each applied voltage a probability of corona occurrence is assigned.