A method for studying partial discharges location and propagation within power transformer winding based on the structural data

Power transformer inner insulation system is a very critical component. Its degradation may pose apparatus to fail while in service. On the other hand, experimental experiences prove that partial discharges are a major source of insulation failure in power transformers. If the deterioration of the insulation system caused by PD activity can be detected at an early stage, preventive maintenance measures may be taken. Because of the complex structure of the transformer, accurate PD location is difficult and is one of the challenges power utilities are faced with. This problem comes to be vital in open access systems. In this paper a theory for locating partial discharge and its propagation along the winding is proposed, which is based on structural data of a transformer. The lumped element winding model is constructed. Quasi-static condition is applied and each turn of the winding is considered as a segment. Then an algorithm is developed to use the constructed matrices for PD location. A software package in Visual Basic environment has been developed. This paper introduces the background theory and utilized techniques.