High-Voltage Testing on Site

Abstract

High-voltage (HV) tests on-site are performed for two different reasons: First, to assure the insulation integrity after new equipment or systems have been assembled on site, and second, to assess the condition of aged equipment, e.g. after maintenance and repair. The first category covers commissioning tests where classical HV withstand voltage tests are nowadays combined more and more with non-destructive dielectric tests, such as C/tanδ and PD measurements to demonstrate the necessary quality and reliability. Such tests complete the quality assurance tests carried out in the factory and should follow their philosophy based on insulation coordination. The aim of the second group of tests, which are commonly referred to as diagnostic tests, is to assess the insulation condition as well as the remaining life time of service-aged equipment. For diagnostic purposes, usually a set of tests and measurements is performed. HV tests after repair are in between these both categories, because the repaired part is new, but the other insulation of the equipment or system is service-aged. After a consideration of the general requirements to HV test systems used on site, the applied test voltages according to IEC 60060-3:2006 are introduced. Moreover, the chapter provides examples for both quality acceptance withstand tests and diagnostic tests on site, which are usually applied for compressed-gas-insulated equipment (GIS), cable systems, power transformers and rotating HV machines.