Partial discharge measurement as a Diagnostic Tool for HV-Equipments

Insulation monitoring and diagnostic are the base of condition maintenance and essential for an economic usage of high voltage equipment. Electrical breakdowns in a small region of the insulating system are called partial discharge. The appearance and the intensity of these partial discharges are a quality criterion for an electrical equipment rating and therefore an estimation of the condition of the insulation system can be done. So the partial discharge measurement has become a fix part in industrial applications as a non destructive high voltage test. It uses the different physical effects in different insulating systems to detect significant parameters to give directly or indirectly information about the equipment condition. Not only high frequency electrical transient phenomena and especially currents are caused by partial discharges also optical, acoustical and chemical reactions and effects occur. Different techniques are in use to observe relevant parameters and are supposed to provide an early warning. In the full paper an overview of partial discharge measurement techniques, particularly in the area of non conventional measurements, for diagnostics is given