Forecasting reliability of transformer populations

The expected replacement wave in the current power grid faces asset managers with challenging questions. Setting up a replacement strategy and planning calls for a forecast of the long term component reliability. For transformers the future failure probability can be predicted based on the ongoing physical degradation processes and the future loading scenarios as input. In previous work we have presented a modeling approach for individual transformers. We here present a probabilistic approach for predicting the reliability of a transformer population from the individual transformer reliabilities. This method has been successfully applied to a small transformer population by calculating the impact of different asset management scenarios.