Power transformer asset management on-line partial discharge measurement-a new approach

The traditional approach to power transformer asset management is largely based on gas-in-oil analysis, wherein generation of specific gases and their levels are used to assess the condition of the transformer. The maintenance decisions that follows usually needs supplementary information like position of the fault within the transformer dielectric structure and realistic risk that poses in operating the transformer. It is well documented that acoustic emission based technique could serve to identify the position of the fault in the electrical apparatus. However, it is not widely known that some thermal faults could be detected and located using acoustic emission technique. This contribution demonstrates using practical case studies how on-line acoustic emission based partial discharge measurement technique could be used to detect transformer faults of thermal origin and also how it could help in managing scientifically transformer assets.