Diagnosis and monitoring of high-voltage insulation using computerized analysis of partial discharge measurements

Transmission of electrical power requires various types of apparatus. All the apparatus and transmission-line conductors must be insulated from the high and extra-high voltages arising from the need of transmitting a large quantum of energy. As the need grows, the quality and reliability of the insulator must also grow to handle extra stresses. Hence an attempt is made to evaluate insulation in power apparatus based on the computerized analysis of partial discharge (PD) testing measurements and observations, leading to the identification of PD fault-sources of electrical insulation degradation. The database offers a decision-making aid for product development and supports condition monitoring, assessing the state of insulation. By conducting suitable experiments on two-electrode models, one does partial discharge characterization by considering one PD defect at a time. Using the database extracted from the various PD distributions attained from physical models fabricated, PD sources or defects in simple power apparatus such as surge arrestors, current transformers and artificially created defects such as slot models and rigid terminal connectors are identified successfully and evaluated. Successful recognition rate is achieved with the developed software package even in the presence of two PD sources; say, surface and internal discharges contributing to electrical insulation degradation.