Failure of transmission line cap and pin insulators under DC stresses

The available statistics on the failure rates of transmission line ceramic cap and pin insulators due to self-shattering for most HVDC operating lines indicate an unacceptably high value. The authors discuss these statistics and the possible primary causes for the high failure rate. They describe some of the research carried out as well as the major results obtained. Some means to improve the quality of insulators for DC applications, and areas for further research are indicated.<
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