Field Results from an Integrated On-Line Transformer Tank and Bushing Monitoring System.
Transformers are a critical part of an electrical utility’s asset base. Loss of a transformer in a transmission utility, generation plant or industrial plant can cost many millions of dollars, depending on how long it is out-of-service.
On-line monitoring and diagnostics is a useful tool to help operators manage their assets and make decisions on continuing operation, maintenance or replacement. Transformer bushings have been identified as the cause of a large number of transformer failures and GE has developed an on-line bushing monitoring system that will monitor the bushing insulation and also detect partial discharge within the bushing and tank.
The bushing/PD monitoring system can be integrated with GE’s existing DGA monitors. It uses sensors on the bushing tap of the transformer to measure the low frequency and high frequency components of the leakage current, to identify changes in the bushing insulation properties and to detect partial discharges within the bushing and transformer tank.
This paper describes the results of field trials of the integrated system on a transformer.