A power transformer consists of several components, e.g. transformer tank with active part and oil-paper insulation, conservator, cooling system, on-load tap changer and oil impregnated bushings. These components can be fitted with various sensors, which are integrated into the online condition monitoring and expert system by means of analogue or digital signals and different protocols e.g. IEC 60870-5-101/104, Modbus, DNP3. The sensor outputs are stored, analysed by means of implemented models and recorded in the IED of the on-line condition monitoring and expert system.
A comprehensive and interactive on-line transformer condition monitoring system integrates all relevant main components of the power transformer within only one system. The database and all algorithms are located on only one IED. Thereby a correlation of all data of the transformer or even of several transformers is possible. The interpretation of the data delivers health information about the transformer and all of its components. The concept of the comprehensive on-line monitoring system is based on field bus and process control technology. This approach gives highest flexibility concerning system architecture. This concept allows monitoring of several transformers with only one server. The analogue signals from the sensors are connected to the bus terminals inside the monitoring cubicle at the transformer. The analogue signals are digitalized and transferred to the server via field bus.
The expert system and its diagnosis functions support the user in making right decisions regarding foresighted operation and maintenance of the power transformer and also early warnings.