On-line condition monitoring of power transformers

The development in sensor and computer technology allows the realisation of on-line monitoring systems for application to power transformers, in order to use this most expensive transmission equipment in the optimum technical and economical manner. This means the controlled utilisation of overload and life capacity of the transformer, as well as early warning in case of an oncoming insulation fault and condition-based maintenance. In this contribution a state-of-the-art monitoring system for power transformers based on field bus technology and process control software is described. The presentation of experiences in operation shows considerable possibilities regarding optimisation of service and early fault recognition.