Corona Rings: Are They Needed? Modeling predicts corona levels based on configuration, hardware and line voltage

摘要

Since 2006, some utilities have been experiencing an increased number of polymer insulator failures on their 115-kV and 138-kV transmission lines. Investigations have shown these failures can be attributed to high electric fields (E-fields) occurring close to, or on the high-voltage end fittings of, these insulators. The findings of the investigations suggest that, contrary to conventional wisdom, it might be necessary to consider the application of corona protection on polymer insulators applied below 161 kV.