Avaliação da Criticidade do Campo Elétrico em Isoladores de Vidro
Keywords: Electrical field, sacrificial ring, glass insulator string, finite element method, pollution, cement reduction
AbstractThis paper presents an evaluation of the electric field criticality and the electric potential distribution in a chain of 69 kV glass insulators. The analysis was performed under different operating conditions: glass chain insulators with cement reduction, with sacrificial ring, with bell touching the glass and under pollution effect. For this, a multhiphysics simulation software was used. As results, it was noted that the cement reduction and the sacrificial ring presence intensified the electric fields values close to the pin of the first insulator of the chain by more than 40%, which could cause flashovers, increase the pin corrosion rate and puncture in the glass, unlike pollution, which didn´t cause significant changes in the electric field. On the other hand, the electric potential distribution along the glass shed of the first insulator remained standardized, with the exception of the cases with sacrificial ring, which resulted in an increase in the electric potential at all points along the glass skirt.