On-line a off-line diagnostics for power station HV equipment

Abstract

Experience accumulated from online and offline diagnostics and nondestructive tests to reliably determine the condition of service-aged HV electrical equipment are discussed. Under test were: switchgear; power transformers; underground transmission lines; metalclad substations; and rotating machines. Methods for assessing the condition of their electrical insulation systems included: partial discharge activity tests and complex conductivity measurements; infrared thermography; dissolved gas analysis; and dissipation-factor measurements applied to current transformers and bushings.