US Patent 10026537 Fault tolerant subsea transformer

According to some embodiments, subsea fault tolerant transformer includes an arrangement of two tanks mounted one above the other. A lower tank houses the transformer windings and core and is below and abutting an upper tank. Both tanks are filled with respective dielectric oil. The electrical terminals for the primary and secondary power connections are on the second/instrument tank and the conductors pass through the instrument tank and then through the shared wall to the transformer tank. The design allows for enhanced cooling of the transformer through a single wall portion of the lower tank as well as fault tolerance associated with double barriers.