Reliability and vulnerability of transformers for electricity transmission and distribution

In the last years the failure frequency of transformers increased, e.g. due to ageing or external hazards. In particular fires and explosions of main oil-filled transformers are considered as critical. Therefore, international experiences of transformer failures at nuclear and non-nuclear power plants and at substations have been investigated in more detail. Consequences of transformer failures with respect to a reliable electricity transmission and distribution as well as measures to enhance the reliability of critical infrastructure and to avoid blackouts are addressed.