An inspection of the most significant components such as converter valves, cables and power transformers showed that the equipment is generally in a good state. In particular, the HVDC transformers (196 MVA HVDC classic units for the 550-kV level on the high voltage side) are still in a healthy condition after 10 years of operation. To get more insight on their ageing and behavior under full load, they were equipped with additional sensors that allow the operator to get a complete picture of the thermal conditions in real time. With the data measured, significantly improved simulation and visualization of thermal images of the transformer now becomes possible. By logging and documenting these pictures, an individual thermal model can be set up. It simulates future transformer operational conditions based on a pre-defined set of parameters and user-defined parameters. Consequently, an improved load prediction algorithm can be implemented for a pre-defined loss of life scenario and for a given time in operation. This so-called digital twin operation enables prediction of loads for the transformer and the transmission line, based on a real-time image of the transformer based on the operation of the individual unit. Basslink’s site engineer Mark Bostedt is convinced that the digital twin will boost the interconnector’s operation: “Siemens’ continuing close cooperation with Basslink is assisting in the development of new software models that will benefit the ongoing successful operation of the Basslink interconnector. Both companies are working collaboratively to reach a favorable outcome.”