As the cabled seafloor observatory network based on constant current power transmission needs constant current branching technology to implement grid topology

there is a variety of primary power supply circuit and branched power supply circuit combining schemes. To solve this problem

a method of selecting constant current power scheme is proposed. According to the working characteristics of constant branching technology

the concept of N loop is proposed and the power scheme is abstracted into a one-to-one correspondence connected graph. In addition

the survival rate is presented as evaluation standards and

a variable time increment method based Monte Carlo method combined with the depth-first-search algorithm is adopted to estimate the survival rate of each power scheme. This method is suitable for optimization options to power supply schemes with known network topological structure. A numerical example shows that the model and algorithm can accurately analyze the influence of power supply solutions on system reliability with good convergence at that. This work is supported by General Armament Department Pre-research Project (No. 51327020105) and National High Technology Research and Development Program of China (863 Program) (No. 2009AAJ128).