Investigation of AC and DC power distributions to seafloor mining equipment

The main goal of this paper is to study and compare different power distribution alternatives for subsea electrical components for deep-sea mining in the Norwegian Sea. Such application requires power delivery in the multi-MW range at water depth of more than 3000 m. Hence, AC (50Hz), DC, high frequency AC and low frequency AC can be possible options to transfer electrical power to the mining equipment. Comparing them at the preliminary stages of projects is beneficial in order to select the most suitable alternative. Minimizing voltage drop and distribution losses, in addition to reducing the number of components, their weight and cost are critical and often conflicting aspects, to design the electrical system appropriately. In this paper, the basic processes of deep-sea mining (regarding Seafloor Massive Sulfides) will be described briefly. In addition, an estimation of the amount of required power to feed the subsea mining equipment for the Norwegian Sea case will be given and finally, different power distribution schemes will be analyzed and compared, using the PowerFactory/DIgSILENT software for simulations.