Fundamentals in computer aided PD processing, PD pattern recognition and automated diagnosis in GIS

The partial discharge (PD) measurement is a sensitive method for testing and monitoring the insulation condition of Hv apparatus. Digital PD measurements have become state of the art. Computer-based PD diagnostic systems nowadays can be used to increase the reliability of modem gas-insulated system (GIS). Also on-line monitoring of HV equipment is becoming increasingly important to enable prevention of a sudden breakdown of PD affected components, On-line monitoring must be done on-site, but an important problem of on-site PD measurement is the superposition of PD data and interference, Furthermore, reliable recognition of the type or nature of the insulation defect is necessary for any risk assessment. Traditionally; this is achieved with reference to expert knowledge. An alternative approach is presented in this paper, which treats the fundamentals of automated computer-based PD diagnosis, taking into account that successful noise suppression is essential for a successful on-site diagnosis.