Progress in the evaluation of solid-core high-voltage bushings

A HIGH-VOLTAGE bushing which successfully sustains repeated application of 60-cycle and impulse test voltages may not be adequate for prolonged operation at rated line-to-ground voltage. Methods to evaluate bushings at voltages slightly in excess of operating voltages have therefore been devised. The techniques developed have been used to evaluate the life characteristics of the solid compound core type of bushing and to provide a routine quality control of bushing production.