A comparison of AC and DC power feeding systems based on the NEMO experiences

The NEMO Collaboration is involved in an intense activity to develop, apply and test technical solutions for an underwater laboratory with two prototypes called NEMO Phase 1 and NEMO Phase 2. In this framework both options of AC and DC power feeding systems have been explored. The design, realization, test and operation of NEMO Phase 1 AC electrical power and control systems were carried out and concluded. The operational experience with this system will be reported. Presently the design and realization of the DC power system of NEMO Phase 2 is under way. Both these systems are described and compared, with a special focus on the results of NEMO Phase 1, on the tower power subsystem, and on the long term high pressure tests that have been carried out on the electric and electronic devices.