Predictive maintenance of electric grid assets: HV transmission line, distribution, substations, rotating machines, switchgears etc * Acceptance tests and commissioning of new installations * Maintenance * Research * Environmental issues * Hazardous materials

Awareness to corona and arcing

The awareness of electrical engineers to corona and arcing effects is growing in the last years and is backed up by worldwide research. Corona and arcing on power lines and substations. besides generating audio noise (environmental consideration) and radio interference (safety issues), accelerate degradation of various grid components such as ceramic and non ceramic insulators, and are indicators of defective components that may cause outage.

Non-Ceramic Insulators (NCI)

With the advent of non-ceramic insulators (NCI), as alternatives to traditional ceramic insulators, new maintenance concerns emerged. Polymer insulators are cheaper and easier to handle than the porcelain or glass insulators and therefore appeal to construction and maintenance managements. But, NCI are susceptible to degradation by corona discharge.

Corona and arcing create corrosive substances

Corona activity creates corrosive substances, like nitrogen oxides and ozone, which degrade the polymer housing and allow moisture and acid to penetrate the fiberglass rod leading thereby to insulators' failure. A fault on a polymer insulator usually progresses rapidly and may eventually lead to line drop.

Reliability of power lines with polymer insulators requires, therefore, efficient and regular UV inspection for corona and arcing, to allow corrective measures to be performed in time.