Predicting Contamination Flashover of Insulators: Successes and Shortcomings of Tests and Simulations

Perhaps no single area of insulator behavior has fascinated researchers more so than predicting flashover under contaminated conditions. For traditional porcelain and glass insulators, there is a large body of literature published that includes both theoretical models and experimental tests to simulate this interesting and practically important aspect of insulator performance. Yet there still some critical gaps in the understanding of this complex problem. This article summarizes the state of the art for porcelain and glass insulators, which are still the workhorses of industry. In such insulators, the dielectric being inorganic, there is no interaction of the surface with the contamination layer on the surface. We know that with nonceramic (composite) insulators, there is an interaction (for example, hydrophobic recovery), which further complicates the flashover process. Needless to say, we understand even less about the flashover process on nonceramic insulators. It is therefore important that this subject be researched further from the point of view of obtaining reliable performance from both ceramic and nonceramic insulators.