Principle Experiment and Analysis of Seawater as a Transmission Circuit in Seafloor Monopolar DC Transmission System

With the seafloor observatory network's long-term,continuous,long-distance power supply characteristics,the adoption of monopolar direct current(DC)transmission mode has become a trend.The use of a length of copper wire of transmission from optic/electric composite cable and the seawater as transmission circuit mode has reduced not only the cost but also the transmission loop loss.The key technology of the seawater as a conductor in monopolar DC transmission mode is analyzed.The main influencing factors of seawater loop resistance are verified by experiment.The potential effect of seawater as a conductor on the marine environment,marine life and human security are dealt with.