Research on insulation condition monitoring system for power transformers

Power transformer is one of the most important components in the power system. The operating reliability of transformers mainly depends on their insulation status. An integrated system which contains the monitoring of gas-in-off analysis (DGA), partial discharge (PD), contamination of the bushing surface, the equivalent capacitance and dissipation factor (tan delta) of the bushing is introduced in this paper. Based on the above parameters, the engineer could get further detailed information about the insulation status of the transformer. This system has been applied in several substations and obtained good results.